diff --git a/examples/parameter_example.yml b/examples/parameter_example.yml
index 6aeeaad3e41498b48e215f0a761ecdffb486a118..996e35e41a3a6090a11ecf30a9decb391865ed63 100644
--- a/examples/parameter_example.yml
+++ b/examples/parameter_example.yml
@@ -338,11 +338,6 @@ EAGLEChemistry:
 
 # Parameters related to star formation models  -----------------------------------------------
 
-# GEAR star formation model (Revaz and Jablonka 2018)
-GEARStarFormation:
-  star_formation_efficiency: 0.01   # star formation efficiency (c_*)
-  maximal_temperature:  3e4         # Upper limit to the temperature of a star forming particle
-
 # EAGLE star formation model (Schaye and Dalla Vecchia 2008)
 EAGLEStarFormation:
   EOS_density_norm_H_p_cm3:          0.1       # Physical density used for the normalisation of the EOS assumed for the star-forming gas in Hydrogen atoms per cm^3.
diff --git a/src/cell.c b/src/cell.c
index 0649d31b38279f3a75ec2b439f71de105425ae27..f4903f024b10c7cc7867291b597a3bdf42997c27 100644
--- a/src/cell.c
+++ b/src/cell.c
@@ -4413,7 +4413,7 @@ void cell_drift_part(struct cell *c, const struct engine *e, int force) {
       if (part_is_active(p, e)) {
         hydro_init_part(p, &e->s->hs);
         chemistry_init_part(p, e->chemistry);
-        star_formation_init_part(p, xp, e->star_formation);
+        star_formation_init_part(p, e->star_formation);
         tracers_after_init(p, xp, e->internal_units, e->physical_constants,
                            with_cosmology, e->cosmology, e->hydro_properties,
                            e->cooling_func, e->time);
diff --git a/src/collectgroup.c b/src/collectgroup.c
index 8dd9e974f41c979f4c50e84fb555f9b80db19e25..d17608d67a291ae412728b3fcd9ea80c192802bf 100644
--- a/src/collectgroup.c
+++ b/src/collectgroup.c
@@ -122,8 +122,7 @@ void collectgroup1_apply(const struct collectgroup1 *grp1, struct engine *e) {
   e->total_nr_cells = grp1->total_nr_cells;
   e->total_nr_tasks = grp1->total_nr_tasks;
   e->tasks_per_cell_max = grp1->tasks_per_cell_max;
-
-  star_formation_logger_add_to_accumulator(&e->sfh, &grp1->sfh);
+  e->sfh = grp1->sfh;
 }
 
 /**
diff --git a/src/cooling/grackle/cooling.h b/src/cooling/grackle/cooling.h
index 57f4b146c451557365e08d260ddd45276844af9c..1abbe5d3827726bde34502cd2b6a1d18cd309950 100644
--- a/src/cooling/grackle/cooling.h
+++ b/src/cooling/grackle/cooling.h
@@ -697,17 +697,6 @@ __attribute__((always_inline)) INLINE static void cooling_cool_part(
   xp->cooling_data.radiated_energy -= hydro_get_mass(p) * cooling_du_dt * dt;
 }
 
-/**
- * @brief Compute the temperature of a #part based on the cooling function.
- *
- * @param phys_const #phys_const data structure.
- * @param hydro_props The properties of the hydro scheme.
- * @param us The internal system of units.
- * @param cosmo #cosmology data structure.
- * @param cooling #cooling_function_data struct.
- * @param p #part data.
- * @param xp Pointer to the #xpart data.
- */
 static INLINE float cooling_get_temperature(
     const struct phys_const* restrict phys_const,
     const struct hydro_props* restrict hydro_props,
@@ -715,30 +704,9 @@ static INLINE float cooling_get_temperature(
     const struct cosmology* restrict cosmo,
     const struct cooling_function_data* restrict cooling,
     const struct part* restrict p, const struct xpart* restrict xp) {
-  // TODO use the grackle library
-
-  /* Physical constants */
-  const double m_H = phys_const->const_proton_mass;
-  const double k_B = phys_const->const_boltzmann_k;
 
-  /* Gas properties */
-  const double T_transition = hydro_props->hydrogen_ionization_temperature;
-  const double mu_neutral = hydro_props->mu_neutral;
-  const double mu_ionised = hydro_props->mu_ionised;
-
-  /* Particle temperature */
-  const double u = hydro_get_physical_internal_energy(p, xp, cosmo);
-
-  /* Temperature over mean molecular weight */
-  const double T_over_mu = hydro_gamma_minus_one * u * m_H / k_B;
-
-  /* Are we above or below the HII -> HI transition? */
-  if (T_over_mu > (T_transition + 1.) / mu_ionised)
-    return T_over_mu * mu_ionised;
-  else if (T_over_mu < (T_transition - 1.) / mu_neutral)
-    return T_over_mu * mu_neutral;
-  else
-    return T_transition;
+  error("This function needs implementing!!");
+  return 0.;
 }
 
 /**
diff --git a/src/engine.c b/src/engine.c
index 33f94e9c16475b5281cdb5948e6b31e1026c7d46..8f14cfd0088cff9d47bee38662a5aeff357dd8e0 100644
--- a/src/engine.c
+++ b/src/engine.c
@@ -5062,11 +5062,6 @@ void engine_init(struct engine *e, struct space *s, struct swift_params *params,
         parser_get_opt_param_double(params, "FOF:delta_time", -1.);
   }
 
-  /* Initialize the star formation history structure */
-  if (e->policy & engine_policy_star_formation) {
-    star_formation_logger_accumulator_init(&e->sfh);
-  }
-
   engine_init_output_lists(e, params);
 }
 
diff --git a/src/engine.h b/src/engine.h
index 967a430871648ac4cb91f390f8b85675a314d3a8..8296933561b5f7664904d439ec6ca20f1e37a4b8 100644
--- a/src/engine.h
+++ b/src/engine.h
@@ -237,7 +237,7 @@ struct engine {
   long long b_updates_since_rebuild;
 
   /* Star formation logger information */
-  struct star_formation_history_accumulator sfh;
+  struct star_formation_history sfh;
 
   /* Properties of the previous step */
   int step_props;
diff --git a/src/hydro/Gadget2/hydro_part.h b/src/hydro/Gadget2/hydro_part.h
index 853d2adf17bc069434562fa96ddb881f760f6830..7a8844d560561dae80c676a0b5bb72b34416d080 100644
--- a/src/hydro/Gadget2/hydro_part.h
+++ b/src/hydro/Gadget2/hydro_part.h
@@ -155,9 +155,6 @@ struct part {
   /*! Black holes information (e.g. swallowing ID) */
   struct black_holes_part_data black_holes_data;
 
-  /* Additional data used by the star formation */
-  struct star_formation_part_data sf_data;
-
   /* Time-step length */
   timebin_t time_bin;
 
diff --git a/src/runner.c b/src/runner.c
index 644d7f6171887a3a44395767353c1de84aa513d9..7320fd8744948632cd6a08b2434768b47d837360 100644
--- a/src/runner.c
+++ b/src/runner.c
@@ -2272,7 +2272,7 @@ void runner_do_ghost(struct runner *r, struct cell *c, int timer) {
             /* Re-initialise everything */
             hydro_init_part(p, hs);
             chemistry_init_part(p, chemistry);
-            star_formation_init_part(p, xp, star_formation);
+            star_formation_init_part(p, star_formation);
             tracers_after_init(p, xp, e->internal_units, e->physical_constants,
                                with_cosmology, e->cosmology,
                                e->hydro_properties, e->cooling_func, e->time);
diff --git a/src/runner_doiact.h b/src/runner_doiact.h
index 1a39c8d49f2c4234c04982e255705f06ec1c5d38..6caa287cf726f85778ef5abdc184acaf759e8b0e 100644
--- a/src/runner_doiact.h
+++ b/src/runner_doiact.h
@@ -884,6 +884,7 @@ void DOSELF_SUBSET(struct runner *r, struct cell *restrict ci,
 
   const int count_i = ci->hydro.count;
   struct part *restrict parts_j = ci->hydro.parts;
+
   /* Loop over the parts in ci. */
   for (int pid = 0; pid < count; pid++) {
 
diff --git a/src/space.c b/src/space.c
index 250af5efafa506408c9fd91c1adffb7cd96a1a21..49c714743728a3b93f631434d87de69a61dd716f 100644
--- a/src/space.c
+++ b/src/space.c
@@ -4365,7 +4365,7 @@ void space_init_parts_mapper(void *restrict map_data, int count,
   for (int k = 0; k < count; k++) {
     hydro_init_part(&parts[k], hs);
     chemistry_init_part(&parts[k], e->chemistry);
-    star_formation_init_part(&parts[k], &xparts[k], e->star_formation);
+    star_formation_init_part(&parts[k], e->star_formation);
     tracers_after_init(&parts[k], &xparts[k], e->internal_units,
                        e->physical_constants, with_cosmology, e->cosmology,
                        e->hydro_properties, e->cooling_func, e->time);
diff --git a/src/star_formation.c b/src/star_formation.c
index 60cff1e2e68feaf7e71705b5079294ec478fad42..698a64cc636dd79f00feac3f6cc88bf519fe09c1 100644
--- a/src/star_formation.c
+++ b/src/star_formation.c
@@ -24,7 +24,6 @@
 #include "part.h"
 #include "restart.h"
 #include "star_formation.h"
-#include "star_formation_io.h"
 #include "units.h"
 
 /**
diff --git a/src/star_formation/EAGLE/star_formation.h b/src/star_formation/EAGLE/star_formation.h
index f2c77e036842b4ca040c58a6bcad1513b03a42bd..694cac1512d91ef3d640185cbf9b614773263a75 100644
--- a/src/star_formation/EAGLE/star_formation.h
+++ b/src/star_formation/EAGLE/star_formation.h
@@ -691,7 +691,6 @@ star_formation_first_init_part(const struct phys_const* restrict phys_const,
  * @param data The global star_formation information.
  */
 __attribute__((always_inline)) INLINE static void star_formation_init_part(
-    struct part* restrict p, struct xpart* restrict xp,
-    const struct star_formation* data) {}
+    struct part* restrict p, const struct star_formation* data) {}
 
 #endif /* SWIFT_EAGLE_STAR_FORMATION_H */
diff --git a/src/star_formation/EAGLE/star_formation_logger.h b/src/star_formation/EAGLE/star_formation_logger.h
index a843f63ce518aa9be6b1d389d42cf71c8608b903..d634c876e52d45588ed0b93c0afc09731317c037 100644
--- a/src/star_formation/EAGLE/star_formation_logger.h
+++ b/src/star_formation/EAGLE/star_formation_logger.h
@@ -87,28 +87,6 @@ INLINE static void star_formation_logger_add(
   sf_update->SFR_inactive += sf_add->SFR_inactive;
 }
 
-/**
- * @brief add a star formation history struct to the engine star formation
- * history accumulator struct
- *
- * @param sf_add the star formation accumulator struct which we want to add to
- * the star formation history
- * @param sf_update the star formation structure which we want to update
- */
-INLINE static void star_formation_logger_add_to_accumulator(
-    struct star_formation_history_accumulator *sf_update,
-    const struct star_formation_history *sf_add) {
-
-  /* Update the SFH structure */
-  sf_update->new_stellar_mass += sf_add->new_stellar_mass;
-
-  sf_update->SFR_active += sf_add->SFR_active;
-
-  sf_update->SFRdt_active += sf_add->SFRdt_active;
-
-  sf_update->SFR_inactive += sf_add->SFR_inactive;
-}
-
 /**
  * @brief Initialize the star formation history structure in the #engine
  *
@@ -127,24 +105,6 @@ INLINE static void star_formation_logger_init(
   sfh->SFR_inactive = 0.f;
 }
 
-/**
- * @brief Initialize the star formation history structure in the #engine
- *
- * @param sfh The pointer to the star formation history structure
- */
-INLINE static void star_formation_logger_accumulator_init(
-    struct star_formation_history_accumulator *sfh) {
-
-  /* Initialize the collecting SFH structure to zero */
-  sfh->new_stellar_mass = 0.f;
-
-  sfh->SFR_active = 0.f;
-
-  sfh->SFRdt_active = 0.f;
-
-  sfh->SFR_inactive = 0.f;
-}
-
 /**
  * @brief Write the final SFH to a file
  *
@@ -157,7 +117,7 @@ INLINE static void star_formation_logger_accumulator_init(
  */
 INLINE static void star_formation_logger_write_to_log_file(
     FILE *fp, const double time, const double a, const double z,
-    const struct star_formation_history_accumulator sf, const int step) {
+    const struct star_formation_history sf, const int step) {
 
   /* Calculate the total SFR */
   const float totalSFR = sf.SFR_active + sf.SFR_inactive;
diff --git a/src/star_formation/EAGLE/star_formation_logger_struct.h b/src/star_formation/EAGLE/star_formation_logger_struct.h
index c03a00c97ead46f552350a43574c5bbe7ac6df1b..2a23659c4d931735d1b82a6143b3d9f871f7137a 100644
--- a/src/star_formation/EAGLE/star_formation_logger_struct.h
+++ b/src/star_formation/EAGLE/star_formation_logger_struct.h
@@ -34,21 +34,4 @@ struct star_formation_history {
   float SFRdt_active;
 };
 
-/* Starformation history struct for the engine.
- Allows to integrate in time some values.
- Nothing to do in EAGLE => copy of star_formation_history */
-struct star_formation_history_accumulator {
-  /*! Total new stellar mass */
-  float new_stellar_mass;
-
-  /*! SFR of all particles */
-  float SFR_inactive;
-
-  /*! SFR of active particles */
-  float SFR_active;
-
-  /*! SFR*dt of active particles */
-  float SFRdt_active;
-};
-
 #endif /* SWIFT_EAGLE_STAR_FORMATION_LOGGER_STRUCT_H */
diff --git a/src/star_formation/EAGLE/star_formation_struct.h b/src/star_formation/EAGLE/star_formation_struct.h
index 8caac49d4b57652c5db9ae93e3789dc690e6d23f..41247e160a3eddbc9184c59b67cfa2a1d7259a05 100644
--- a/src/star_formation/EAGLE/star_formation_struct.h
+++ b/src/star_formation/EAGLE/star_formation_struct.h
@@ -29,6 +29,4 @@ struct star_formation_xpart_data {
   float SFR;
 };
 
-struct star_formation_part_data {};
-
 #endif /* SWIFT_EAGLE_STAR_FORMATION_STRUCT_H */
diff --git a/src/star_formation/GEAR/star_formation.h b/src/star_formation/GEAR/star_formation.h
index ac423a51865609460e870f65b1eeeb266182e2ef..c479feb5c66328f9fab8bf62593ca66b6658b79e 100644
--- a/src/star_formation/GEAR/star_formation.h
+++ b/src/star_formation/GEAR/star_formation.h
@@ -1,7 +1,6 @@
 /*******************************************************************************
  * This file is part of SWIFT.
- * Coypright (c) 2019 Loic Hausammann (loic.hausammann@epfl.ch)
- *               2019 Fabien Jeanquartier (fabien.jeanquartier@epfl.ch)
+ * Copyright (c) 2018 Folkert Nobels (nobels@strw.leidenuniv.nl)
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published
@@ -21,24 +20,20 @@
 #define SWIFT_GEAR_STAR_FORMATION_H
 
 /* Local includes */
-#include "cooling.h"
 #include "cosmology.h"
-#include "engine.h"
 #include "entropy_floor.h"
 #include "error.h"
 #include "hydro_properties.h"
 #include "parser.h"
 #include "part.h"
 #include "physical_constants.h"
-#include "random.h"
-#include "star_formation_struct.h"
 #include "units.h"
 
 /**
  * @brief Calculate if the gas has the potential of becoming
  * a star.
  *
- * Use the star formation criterion given by eq. 3 in Revaz & Jablonka 2018.
+ * No star formation should occur, so return 0.
  *
  * @param starform the star formation law properties to use.
  * @param p the gas particles.
@@ -51,7 +46,7 @@
  *
  */
 INLINE static int star_formation_is_star_forming(
-    struct part* restrict p, struct xpart* restrict xp,
+    const struct part* restrict p, const struct xpart* restrict xp,
     const struct star_formation* starform, const struct phys_const* phys_const,
     const struct cosmology* cosmo,
     const struct hydro_props* restrict hydro_props,
@@ -59,43 +54,14 @@ INLINE static int star_formation_is_star_forming(
     const struct cooling_function_data* restrict cooling,
     const struct entropy_floor_properties* restrict entropy_floor) {
 
-  const float temperature = cooling_get_temperature(phys_const, hydro_props, us,
-                                                    cosmo, cooling, p, xp);
-
-  const float temperature_max = starform->maximal_temperature;
-
-  /* Check the temperature criterion */
-  if (temperature > temperature_max) {
-    return 0;
-  }
-
-  /* Get the required variables */
-  const float sigma2 = p->sf_data.sigma2;
-  const float n_jeans_2_3 = starform->n_jeans_2_3;
-
-  const float h = p->h;
-  const float density = hydro_get_physical_density(p, cosmo);
-
-  // TODO use GRACKLE */
-  const float mu = hydro_props->mu_neutral;
-
-  /* Compute the density criterion */
-  const float coef =
-      M_PI_4 / (phys_const->const_newton_G * n_jeans_2_3 * h * h);
-  const float density_criterion =
-      coef * (hydro_gamma * phys_const->const_boltzmann_k * temperature /
-                  (mu * phys_const->const_proton_mass) +
-              sigma2);
-
-  /* Check the density criterion */
-  return density > density_criterion;
+  return 0;
 }
 
 /**
- * @brief Compute the star-formation rate of a given particle.
+ * @brief Compute the star-formation rate of a given particle and store
+ * it into the #xpart.
  *
- * Nothing to do here. Everything is done in
- * #star_formation_should_convert_to_star.
+ * Nothing to do here.
  *
  * @param p #part.
  * @param xp the #xpart.
@@ -105,15 +71,15 @@ INLINE static int star_formation_is_star_forming(
  * @param dt_star The time-step of this particle.
  */
 INLINE static void star_formation_compute_SFR(
-    struct part* restrict p, struct xpart* restrict xp,
+    const struct part* restrict p, struct xpart* restrict xp,
     const struct star_formation* starform, const struct phys_const* phys_const,
     const struct cosmology* cosmo, const double dt_star) {}
 
 /**
  * @brief Decides whether a particle should be converted into a
  * star or not.
-
- * Compute the star formation rate from eq. 4 in Revaz & Jablonka 2012.
+ *
+ * No SF should occur, so return 0.
  *
  * @param p The #part.
  * @param xp The #xpart.
@@ -123,38 +89,18 @@ INLINE static void star_formation_compute_SFR(
  * @return 1 if a conversion should be done, 0 otherwise.
  */
 INLINE static int star_formation_should_convert_to_star(
-    struct part* p, struct xpart* xp, const struct star_formation* starform,
-    const struct engine* e, const double dt_star) {
-
-  const struct phys_const* phys_const = e->physical_constants;
-  const struct cosmology* cosmo = e->cosmology;
-
-  /* Check that we are running a full time step */
-  if (dt_star == 0.) {
-    return 0;
-  }
-
-  /* Get a few variables */
-  const float G = phys_const->const_newton_G;
-  const float density = hydro_get_physical_density(p, cosmo);
-
-  /* Compute the probability */
-  const float inv_free_fall_time =
-      sqrtf(density * 32.f * G * 0.33333333f * M_1_PI);
-  const float prob = 1.f - exp(-starform->star_formation_efficiency *
-                               inv_free_fall_time * dt_star);
-
-  /* Roll the dice... */
-  const float random_number =
-      random_unit_interval(p->id, e->ti_current, random_number_star_formation);
+    const struct part* p, const struct xpart* xp,
+    const struct star_formation* starform, const struct engine* e,
+    const double dt_star) {
 
-  /* Can we form a star? */
-  return random_number < prob;
+  return 0;
 }
 
 /**
  * @brief Update the SF properties of a particle that is not star forming.
  *
+ * Nothing to do here.
+ *
  * @param p The #part.
  * @param xp The #xpart.
  * @param e The #engine.
@@ -169,6 +115,8 @@ INLINE static void star_formation_update_part_not_SFR(
  * @brief Copies the properties of the gas particle over to the
  * star particle.
  *
+ * Nothing to do here.
+ *
  * @param e The #engine
  * @param p the gas particles.
  * @param xp the additional properties of the gas particles.
@@ -185,33 +133,21 @@ INLINE static void star_formation_copy_properties(
     const struct phys_const* phys_const,
     const struct hydro_props* restrict hydro_props,
     const struct unit_system* restrict us,
-    const struct cooling_function_data* restrict cooling) {
-
-  /* Store the current mass */
-  sp->mass = hydro_get_mass(p);
-  sp->birth.mass = sp->mass;
-
-  /* Store either the birth_scale_factor or birth_time depending  */
-  if (with_cosmology) {
-    sp->birth_scale_factor = cosmo->a;
-  } else {
-    sp->birth_time = e->time;
-  }
-
-  // TODO copy only metals
-  /* Store the chemistry struct in the star particle */
-  sp->chemistry_data = p->chemistry_data;
-
-  /* Store the tracers data */
-  sp->tracers_data = xp->tracers_data;
-
-  /* Store the birth density in the star particle */
-  sp->birth.density = hydro_get_physical_density(p, cosmo);
+    const struct cooling_function_data* restrict cooling) {}
 
-  /* Store the birth temperature*/
-  sp->birth.temperature = cooling_get_temperature(phys_const, hydro_props, us,
-                                                  cosmo, cooling, p, xp);
-}
+/**
+ * @brief initialization of the star formation law
+ *
+ * @param parameter_file The parsed parameter file
+ * @param phys_const Physical constants in internal units
+ * @param us The current internal system of units
+ * @param starform the star formation law properties to initialize
+ *
+ */
+INLINE static void starformation_init_backend(
+    struct swift_params* parameter_file, const struct phys_const* phys_const,
+    const struct unit_system* us, const struct hydro_props* hydro_props,
+    const struct star_formation* starform) {}
 
 /**
  * @brief Prints the used parameters of the star formation law
@@ -220,6 +156,7 @@ INLINE static void star_formation_copy_properties(
  */
 INLINE static void starformation_print_backend(
     const struct star_formation* starform) {
+
   message("Star formation law is 'GEAR'");
 }
 
@@ -227,22 +164,12 @@ INLINE static void starformation_print_backend(
  * @brief Finishes the density calculation.
  *
  * @param p The particle to act upon
- * @param xp The extended particle data to act upon
- * @param sf The global star_formation information.
+ * @param cd The global star_formation information.
  * @param cosmo The current cosmological model.
  */
 __attribute__((always_inline)) INLINE static void star_formation_end_density(
-    struct part* restrict p, const struct star_formation* sf,
-    const struct cosmology* cosmo) {
-
-  // TODO move into pressure floor
-  /* To finish the turbulence estimation we devide by the density */
-  p->sf_data.sigma2 /=
-      pow_dimension(p->h) * hydro_get_physical_density(p, cosmo);
-
-  /* Add the cosmological factor */
-  p->sf_data.sigma2 *= cosmo->a * cosmo->a;
-}
+    struct part* restrict p, const struct star_formation* cd,
+    const struct cosmology* cosmo) {}
 
 /**
  * @brief Sets all particle fields to sensible values when the #part has 0 ngbs.
@@ -256,46 +183,39 @@ __attribute__((always_inline)) INLINE static void
 star_formation_part_has_no_neighbours(struct part* restrict p,
                                       struct xpart* restrict xp,
                                       const struct star_formation* cd,
-                                      const struct cosmology* cosmo) {
-
-  // TODO move into pressure floor
-  /* If part has 0 neighbours, the estimation of turbulence is 0 */
-  p->sf_data.sigma2 = 0.f;
-}
+                                      const struct cosmology* cosmo) {}
 
 /**
  * @brief Sets the star_formation properties of the (x-)particles to a valid
  * start state.
  *
- * @param p Pointer to the particle data.
- * @param xp Pointer to extended particle data
- * @param data The global star_formation information.
- */
-__attribute__((always_inline)) INLINE static void star_formation_init_part(
-    struct part* restrict p, struct xpart* restrict xp,
-    const struct star_formation* data) {
-  p->sf_data.sigma2 = 0.f;
-}
-
-/**
- * @brief Sets the star_formation properties of the (x-)particles to a valid
- * start state.
+ * Nothing to do here.
+ *
  * @param phys_const The physical constant in internal units.
  * @param us The unit system.
  * @param cosmo The current cosmological model.
  * @param data The global star_formation information used for this run.
  * @param p Pointer to the particle data.
+ * @param xp Pointer to the extended particle data.
  */
 __attribute__((always_inline)) INLINE static void
 star_formation_first_init_part(const struct phys_const* restrict phys_const,
                                const struct unit_system* restrict us,
                                const struct cosmology* restrict cosmo,
                                const struct star_formation* data,
-                               struct part* restrict p,
-                               struct xpart* restrict xp) {
+                               const struct part* restrict p,
+                               struct xpart* restrict xp) {}
 
-  /* Nothing special here */
-  star_formation_init_part(p, xp, data);
-}
+/**
+ * @brief Sets the star_formation properties of the (x-)particles to a valid
+ * start state.
+ *
+ * Nothing to do here.
+ *
+ * @param p Pointer to the particle data.
+ * @param data The global star_formation information.
+ */
+__attribute__((always_inline)) INLINE static void star_formation_init_part(
+    struct part* restrict p, const struct star_formation* data) {}
 
 #endif /* SWIFT_GEAR_STAR_FORMATION_H */
diff --git a/src/star_formation/GEAR/star_formation_iact.h b/src/star_formation/GEAR/star_formation_iact.h
index 7325b92af2840b317cf1a924a1e509b34bdffba3..749b608068650a27cbe4c9a0ca4126d2740337f3 100644
--- a/src/star_formation/GEAR/star_formation_iact.h
+++ b/src/star_formation/GEAR/star_formation_iact.h
@@ -1,7 +1,6 @@
 /*******************************************************************************
  * This file is part of SWIFT.
- * Coypright (c) 2019 Loic Hausammann (loic.hausammann@epfl.ch)
- *               2019 Fabien Jeanquartier (fabien.jeanquartier@epfl.ch)
+ * Copyright (c) 2019 Loic Hausammann (loic.hausammann@epfl.ch)
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published
@@ -29,8 +28,6 @@
  * @brief do star_formation computation after the runner_iact_density (symmetric
  * version)
  *
- * Compute the velocity dispersion follow eq. 2 in Revaz & Jablonka 2018.
- *
  * @param r2 Comoving square distance between the two particles.
  * @param dx Comoving vector separating both particles (pi - pj).
  * @param hi Comoving smoothing-length of particle i.
@@ -42,28 +39,7 @@
  */
 __attribute__((always_inline)) INLINE static void runner_iact_star_formation(
     float r2, const float *dx, float hi, float hj, struct part *restrict pi,
-    struct part *restrict pj, float a, float H) {
-
-  float wi;
-  float wj;
-  /* Evaluation of the SPH kernel */
-  kernel_eval(sqrt(r2) / hi, &wi);
-  kernel_eval(sqrt(r2) / hj, &wj);
-
-  /* Delta v */
-  float dv[3] = {pi->v[0] - pj->v[0], pi->v[1] - pj->v[1], pi->v[2] - pj->v[2]};
-
-  /* Norms at power 2 */
-  const float norm_v2 = dv[0] * dv[0] + dv[1] * dv[1] + dv[2] * dv[2];
-  const float norm_x2 = dx[0] * dx[0] + dx[1] * dx[1] + dx[2] * dx[2];
-
-  /* Compute the velocity dispersion */
-  const float sigma2 = norm_v2 + H * norm_x2;
-
-  /* Compute the velocity dispersion */
-  pi->sf_data.sigma2 += sigma2 * wi * hydro_get_mass(pj);
-  pj->sf_data.sigma2 += sigma2 * wj * hydro_get_mass(pi);
-}
+    struct part *restrict pj, float a, float H) {}
 
 /**
  * @brief do star_formation computation after the runner_iact_density (non
@@ -82,23 +58,6 @@ __attribute__((always_inline)) INLINE static void
 runner_iact_nonsym_star_formation(float r2, const float *dx, float hi, float hj,
                                   struct part *restrict pi,
                                   const struct part *restrict pj, float a,
-                                  float H) {
-  float wi;
-  /* Evaluation of the SPH kernel */
-  kernel_eval(sqrt(r2) / hi, &wi);
-
-  /* Delta v */
-  float dv[3] = {pi->v[0] - pj->v[0], pi->v[1] - pj->v[1], pi->v[2] - pj->v[2]};
-
-  /* Norms at power 2 */
-  const float norm_v2 = dv[0] * dv[0] + dv[1] * dv[1] + dv[2] * dv[2];
-  const float norm_x2 = dx[0] * dx[0] + dx[1] * dx[1] + dx[2] * dx[2];
-
-  /* Compute the velocity dispersion */
-  const float sigma2 = norm_v2 + H * norm_x2;
-
-  /* Compute the velocity dispersion */
-  pi->sf_data.sigma2 += sigma2 * wi * hydro_get_mass(pj);
-}
+                                  float H) {}
 
 #endif /* SWIFT_GEAR_STAR_FORMATION_IACT_H */
diff --git a/src/star_formation/GEAR/star_formation_io.h b/src/star_formation/GEAR/star_formation_io.h
index 3e021f7844c1deaeca40d7144d6f7b69cb6c2bdb..6ef04c49c4abcd00175aaa164271628a9ff89360 100644
--- a/src/star_formation/GEAR/star_formation_io.h
+++ b/src/star_formation/GEAR/star_formation_io.h
@@ -1,7 +1,6 @@
 /*******************************************************************************
  * This file is part of SWIFT.
- * Coypright (c) 2019 Loic Hausammann (loic.hausammann@epfl.ch)
- *               2019 Fabien Jeanquartier (fabien.jeanquartier@epfl.ch)
+ * Copyright (c) 2018 Folkert Nobels (nobels@strw.leidenuniv.nl)
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published
@@ -38,40 +37,8 @@
 __attribute__((always_inline)) INLINE static int star_formation_write_particles(
     const struct part* parts, const struct xpart* xparts,
     struct io_props* list) {
-  /* Nothing to write here */
-  return 0;
-}
 
-/**
- * @brief initialization of the star formation law
- *
- * @param parameter_file The parsed parameter file
- * @param phys_const Physical constants in internal units
- * @param us The current internal system of units
- * @param starform the star formation law properties to initialize
- *
- */
-INLINE static void starformation_init_backend(
-    struct swift_params* parameter_file, const struct phys_const* phys_const,
-    const struct unit_system* us, const struct hydro_props* hydro_props,
-    struct star_formation* starform) {
-
-  // TODO move into pressure floor
-  starform->n_jeans_2_3 =
-      parser_get_param_float(parameter_file, "GEARStarFormation:NJeans");
-  starform->n_jeans_2_3 = pow(starform->n_jeans_2_3, 2. / 3.);
-
-  /* Star formation efficiency */
-  starform->star_formation_efficiency = parser_get_param_double(
-      parameter_file, "GEARStarFormation:star_formation_efficiency");
-
-  /* Maximum temperature for star formation */
-  starform->maximal_temperature = parser_get_param_double(
-      parameter_file, "GEARStarFormation:maximal_temperature");
-
-  /* Apply unit change */
-  starform->maximal_temperature *=
-      units_cgs_conversion_factor(us, UNIT_CONV_TEMPERATURE);
+  return 0;
 }
 
 #endif /* SWIFT_STAR_FORMATION_GEAR_IO_H */
diff --git a/src/star_formation/GEAR/star_formation_logger.h b/src/star_formation/GEAR/star_formation_logger.h
index 84475909c0f524a4f930a48dbcc3b0943719f8b0..5b9e033d21d3d202f3c289d1dd6a843ba17fa524 100644
--- a/src/star_formation/GEAR/star_formation_logger.h
+++ b/src/star_formation/GEAR/star_formation_logger.h
@@ -1,7 +1,6 @@
 /*******************************************************************************
  * This file is part of SWIFT.
- * Coypright (c) 2019 Loic Hausammann (loic.hausammann@epfl.ch)
- *               2019 Fabien Jeanquartier (fabien.jeanquartier@epfl.ch)
+ * Copyright (c) 2019 Folkert Nobels (nobels@strw.leidenuniv.nl)
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published
@@ -28,28 +27,16 @@
 #include "hydro.h"
 #include "part.h"
 #include "star_formation_logger_struct.h"
-#include "units.h"
 
 /**
- * @brief Update the stellar quantities in the current cell after creating
- * the new star particle spart sp.
+ * @brief Update the stellar mass in the current cell after creating
+ * the new star particle spart sp
  *
- * @param time_step, the current time step of the simulation
  * @param sp new created star particle
  * @param sf the star_formation_history struct of the current cell
  */
 INLINE static void star_formation_logger_log_new_spart(
-    const struct spart *sp, struct star_formation_history *sf) {
-
-  /* Add mass of created sparticle to the total stellar mass in this cell */
-  sf->new_stellar_mass += sp->mass;
-
-  /* Increase the number of stars */
-  sf->number_new_stars += 1;
-
-  /* No need to deal with the integrated quantities, only the engine's one is
-   * updated */
-}
+    struct spart *sp, struct star_formation_history *sf) {}
 
 /**
  * @brief Initialize the star formation history struct in the case the cell is
@@ -58,25 +45,7 @@ INLINE static void star_formation_logger_log_new_spart(
  * @param sf the star_formation_history struct we want to initialize
  */
 INLINE static void star_formation_logger_log_inactive_cell(
-    struct star_formation_history *sf) {
-
-  /* Initialize the stellar mass to zero */
-  sf->new_stellar_mass = 0.f;
-
-  /* initialize number of stars to zero*/
-  sf->number_new_stars = 0;
-}
-/**
- * @brief Initialize the star formation history structure in the #engine
- *
- * @param sfh The pointer to the star formation history structure
- */
-INLINE static void star_formation_logger_init(
-    struct star_formation_history *sfh) {
-  /* Initialize the collecting SFH structure to zero */
-  sfh->new_stellar_mass = 0.f;
-  sfh->number_new_stars = 0;
-}
+    struct star_formation_history *sf) {}
 
 /**
  * @brief add a star formation history struct to an other star formation history
@@ -88,12 +57,29 @@ INLINE static void star_formation_logger_init(
  */
 INLINE static void star_formation_logger_add(
     struct star_formation_history *sf_update,
-    const struct star_formation_history *sf_add) {
+    const struct star_formation_history *sf_add) {}
+
+/**
+ * @brief Initialize the star formation history structure in the #engine
+ *
+ * @param sfh The pointer to the star formation history structure
+ */
+INLINE static void star_formation_logger_init(
+    struct star_formation_history *sfh) {}
 
-  /* Update the SFH structure */
-  sf_update->number_new_stars += sf_add->number_new_stars;
-  sf_update->new_stellar_mass += sf_add->new_stellar_mass;
-}
+/**
+ * @brief Write the final SFH to a file
+ *
+ * @param fp The file to write to.
+ * @param time the simulation time (time since Big Bang) in internal units.
+ * @param a the scale factor.
+ * @param z the redshift.
+ * @param sf the #star_formation_history struct.
+ * @param step The time-step of the simulation.
+ */
+INLINE static void star_formation_logger_write_to_log_file(
+    FILE *fp, const double time, const double a, const double z,
+    const struct star_formation_history sf, const int step) {}
 
 /**
  * @brief Initialize the SFH logger file
@@ -104,47 +90,13 @@ INLINE static void star_formation_logger_add(
  */
 INLINE static void star_formation_logger_init_log_file(
     FILE *fp, const struct unit_system *restrict us,
-    const struct phys_const *phys_const) {
-
-  /* Write some general text to the logger file */
-  fprintf(fp, "# Star Formation History Logger file\n");
-  fprintf(fp, "######################################################\n");
-  fprintf(fp, "# The quantities are all given in internal physical units!\n");
-  fprintf(fp, "#\n");
-  fprintf(fp, "# (0) Simulation step\n");
-  fprintf(fp,
-          "# (1) Time since Big Bang (cosmological run), Time since start of "
-          "the simulation (non-cosmological run).\n");
-  fprintf(fp, "#     Unit = %e seconds\n", us->UnitTime_in_cgs);
-  fprintf(fp, "#     Unit = %e yr or %e Myr\n", 1.f / phys_const->const_year,
-          1.f / phys_const->const_year / 1e6);
-  fprintf(fp, "# (2) Scale factor (no unit)\n");
-  fprintf(fp, "# (3) Redshift     (no unit)\n");
-  fprintf(fp,
-          "# (4) Total number of stars formed in the simulation (no unit)\n");
-  fprintf(fp, "# (5) Total stellar mass formed in the simulation.\n");
-  fprintf(fp, "#     Unit = %e gram\n", us->UnitMass_in_cgs);
-  fprintf(fp, "#     Unit = %e solar mass\n",
-          1.f / phys_const->const_solar_mass);
-  fprintf(fp,
-          "# (6) Number of stars formed in the current time step (no unit).\n");
-  fprintf(fp, "# (7) Mass of stars formed in the current time step.\n");
-  fprintf(fp, "#     Unit = %e gram\n", us->UnitMass_in_cgs);
-  fprintf(fp, "#     Unit = %e solar mass\n",
-          1.f / phys_const->const_solar_mass);
-  fprintf(fp,
-          "# (0)         (1)            (2)          (3)                   (4) "
-          "      (5)        (6)        (7)\n");
-}
+    const struct phys_const *phys_const) {}
 
 /**
  * @brief Add the SFR tracer to the total active SFR of this cell
  *
- * Nothing to do here
- *
  * @param p the #part
  * @param xp the #xpart
- *
  * @param sf the SFH logger struct
  * @param dt_star The length of the time-step in physical internal units.
  */
@@ -156,8 +108,6 @@ INLINE static void star_formation_logger_log_active_part(
  * @brief Add the SFR tracer to the total inactive SFR of this cell as long as
  * the SFR tracer is larger than 0
  *
- * Nothing to do here
- *
  * @param p the #part
  * @param xp the #xpart
  * @param sf the SFH logger struct
@@ -166,57 +116,4 @@ INLINE static void star_formation_logger_log_inactive_part(
     const struct part *p, const struct xpart *xp,
     struct star_formation_history *sf) {}
 
-/**
- * @brief add a star formation history struct to an other star formation history
- * struct
- *
- * @param sf_add the star formation struct which we want to add to the star
- * formation history
- * @param sf_update the star formation structure which we want to update
- */
-INLINE static void star_formation_logger_add_to_accumulator(
-    struct star_formation_history_accumulator *sf_update,
-    const struct star_formation_history *sf_add) {
-
-  /* Update the SFH structure */
-  sf_update->number_new_stars = sf_add->number_new_stars;
-  sf_update->new_stellar_mass = sf_add->new_stellar_mass;
-  sf_update->total_number_stars += sf_add->number_new_stars;
-  sf_update->total_stellar_mass += sf_add->new_stellar_mass;
-}
-
-/**
- * @brief Write the final SFH to a file
- *
- * @param fp The file to write to.
- * @param time the simulation time (time since Big Bang) in internal units.
- * @param a the scale factor.
- * @param z the redshift.
- * @param sf the #star_formation_history struct.
- * @param step The time-step of the simulation.
- */
-INLINE static void star_formation_logger_write_to_log_file(
-    FILE *fp, const double time, const double a, const double z,
-    struct star_formation_history_accumulator sf, const int step) {
-
-  fprintf(fp, "%6d %16e %12.7f %14e %14ld %14e %14ld %14e\n", step, time, a, z,
-          sf.total_number_stars, sf.total_stellar_mass, sf.number_new_stars,
-          sf.new_stellar_mass);
-}
-
-/**
- * @brief Initialize the star formation history struct in the #engine when
- * starting the simulation.
- *
- * @param sfh the star_formation_history struct we want to initialize
- */
-INLINE static void star_formation_logger_accumulator_init(
-    struct star_formation_history_accumulator *sfh) {
-  /* Initialize all values to zero */
-  sfh->new_stellar_mass = 0.f;
-  sfh->number_new_stars = 0;
-  sfh->total_number_stars = 0;
-  sfh->total_stellar_mass = 0.f;
-}
-
 #endif /* SWIFT_GEAR_STARFORMATION_LOGGER_H */
diff --git a/src/star_formation/GEAR/star_formation_logger_struct.h b/src/star_formation/GEAR/star_formation_logger_struct.h
index 63e3af06a7cd5af375662a1ba28dc5000a69dc3f..04b5dfdc038f7b684cfb1f2079d13eb312624b3f 100644
--- a/src/star_formation/GEAR/star_formation_logger_struct.h
+++ b/src/star_formation/GEAR/star_formation_logger_struct.h
@@ -1,7 +1,6 @@
 /*******************************************************************************
  * This file is part of SWIFT.
- * Coypright (c) 2019 Loic Hausammann (loic.hausammann@epfl.ch)
- *               2019 Fabien Jeanquartier (fabien.jeanquartier@epfl.ch)
+ * Copyright (c) 2019 Folkert Nobels (nobels@strw.leidenuniv.nl)
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published
@@ -20,33 +19,7 @@
 #ifndef SWIFT_GEAR_STAR_FORMATION_LOGGER_STRUCT_H
 #define SWIFT_GEAR_STAR_FORMATION_LOGGER_STRUCT_H
 
-/**
- * Structure containing the star formation information from the cells.
- */
-struct star_formation_history {
-  /*! Stellar mass created in the current timestep */
-  float new_stellar_mass;
+/* Starformation history struct */
+struct star_formation_history {};
 
-  /*! Number of stars created in this timestep */
-  long int number_new_stars;
-};
-
-/**
- * Structure containing the global star formation information (including time
- * integrated variables).
- */
-struct star_formation_history_accumulator {
-  /*! Total stellar mass from the begining of the simulation */
-  float total_stellar_mass;
-
-  /*! Total number of stars */
-  long int total_number_stars;
-
-  /*! Stellar mass created in the current timestep */
-  float new_stellar_mass;
-
-  /*! Number of stars created in this timestep */
-  long int number_new_stars;
-};
-
-#endif /* SWIFT_GEAR_STAR_FORMATION_LOGGER_STRUCT_H */
+#endif /* SWIFT_NONE_STAR_FORMATION_STRUCT_H */
diff --git a/src/star_formation/GEAR/star_formation_struct.h b/src/star_formation/GEAR/star_formation_struct.h
index 2e9a7548f83ca6ae9bb78ee7bcf4be69a0a31489..9b4e216fd2955f29d89dade6ee46c0e1af715cdb 100644
--- a/src/star_formation/GEAR/star_formation_struct.h
+++ b/src/star_formation/GEAR/star_formation_struct.h
@@ -25,27 +25,7 @@
  */
 struct star_formation_xpart_data {};
 
-struct star_formation_part_data {
-  // TODO move it to the pressure floor
-  /*! Estimation of local turbulence (squared) */
-  float sigma2;
-};
-
-/**
- * @brief Global star formation properties
- */
-struct star_formation {
-
-  // TODO move it to pressure floor
-  /*! Number of particle required to resolved the Jeans criterion (at power 2/3)
-   */
-  float n_jeans_2_3;
-
-  /*! Maximal temperature for forming a star */
-  float maximal_temperature;
-
-  /*! Star formation efficiency */
-  float star_formation_efficiency;
-};
+/* Starformation struct */
+struct star_formation {};
 
 #endif /* SWIFT_GEAR_STAR_FORMATION_STRUCT_H */
diff --git a/src/star_formation/none/star_formation.h b/src/star_formation/none/star_formation.h
index 6b83010ec5f8935778af8c9ad21010ff3452fc0e..412bda2cc356729bb9f3e3657689fb5bb7b36d8f 100644
--- a/src/star_formation/none/star_formation.h
+++ b/src/star_formation/none/star_formation.h
@@ -220,7 +220,6 @@ star_formation_first_init_part(const struct phys_const* restrict phys_const,
  * @param data The global star_formation information.
  */
 __attribute__((always_inline)) INLINE static void star_formation_init_part(
-    struct part* restrict p, struct xpart* restrict xp,
-    const struct star_formation* data) {}
+    struct part* restrict p, const struct star_formation* data) {}
 
 #endif /* SWIFT_NONE_STAR_FORMATION_H */
diff --git a/src/star_formation/none/star_formation_logger.h b/src/star_formation/none/star_formation_logger.h
index 552df0c6cae533d1eb2678cb23dd675e0a058715..b4e6987c03d295348fc8c22d66cb20d10e54378c 100644
--- a/src/star_formation/none/star_formation_logger.h
+++ b/src/star_formation/none/star_formation_logger.h
@@ -59,18 +59,6 @@ INLINE static void star_formation_logger_add(
     struct star_formation_history *sf_update,
     const struct star_formation_history *sf_add) {}
 
-/**
- * @brief add a star formation history accumulator struct to an other star
- * formation history struct
- *
- * @param sf_add the star formation accumulator struct which we want to add to
- * the star formation history
- * @param sf_update the star formation structure which we want to update
- */
-INLINE static void star_formation_logger_add_to_accumulator(
-    struct star_formation_history_accumulator *sf_update,
-    const struct star_formation_history *sf_add) {}
-
 /**
  * @brief Initialize the star formation history structure in the #engine
  *
@@ -79,14 +67,6 @@ INLINE static void star_formation_logger_add_to_accumulator(
 INLINE static void star_formation_logger_init(
     struct star_formation_history *sfh) {}
 
-/**
- * @brief Initialize the star formation history structure in the #engine
- *
- * @param sfh The pointer to the star formation history structure
- */
-INLINE static void star_formation_logger_accumulator_init(
-    struct star_formation_history_accumulator *sfh) {}
-
 /**
  * @brief Write the final SFH to a file
  *
@@ -94,12 +74,12 @@ INLINE static void star_formation_logger_accumulator_init(
  * @param time the simulation time (time since Big Bang) in internal units.
  * @param a the scale factor.
  * @param z the redshift.
- * @param sf the #star_formation_history_accumulator struct.
+ * @param sf the #star_formation_history struct.
  * @param step The time-step of the simulation.
  */
 INLINE static void star_formation_logger_write_to_log_file(
     FILE *fp, const double time, const double a, const double z,
-    const struct star_formation_history_accumulator sf, const int step) {}
+    const struct star_formation_history sf, const int step) {}
 
 /**
  * @brief Initialize the SFH logger file
diff --git a/src/star_formation/none/star_formation_logger_struct.h b/src/star_formation/none/star_formation_logger_struct.h
index b60c64f2eb47894db828a1bde0ca20803892c7db..9efda271da96faf2088169fd75d0e3c01247a429 100644
--- a/src/star_formation/none/star_formation_logger_struct.h
+++ b/src/star_formation/none/star_formation_logger_struct.h
@@ -22,10 +22,4 @@
 /* Starformation history struct */
 struct star_formation_history {};
 
-/* Starformation history accumulator struct.
-   This structure is only defined in the engine and
-   allows the user to integrate some quantities over time.
-*/
-struct star_formation_history_accumulator {};
-
 #endif /* SWIFT_NONE_STAR_FORMATION_STRUCT_H */
diff --git a/src/star_formation/none/star_formation_struct.h b/src/star_formation/none/star_formation_struct.h
index 2f5241a58caf1ca70fa98a40d467c8ff5a3237f7..27a2adaf83d0a02a0d08e7eef8b45bea630689e4 100644
--- a/src/star_formation/none/star_formation_struct.h
+++ b/src/star_formation/none/star_formation_struct.h
@@ -25,10 +25,4 @@
  */
 struct star_formation_xpart_data {};
 
-/**
- * @brief Star-formation-related properties stored in the particle
- * data.
- */
-struct star_formation_part_data {};
-
 #endif /* SWIFT_NONE_STAR_FORMATION_STRUCT_H */
diff --git a/src/stars.h b/src/stars.h
index dea6e07a87cabd7d1778ec2a850be4f3b16b04b0..dd8390e0206580fc2a07a08e51bb69c6ee5ab5ed 100644
--- a/src/stars.h
+++ b/src/stars.h
@@ -29,9 +29,6 @@
 #elif defined(STARS_EAGLE)
 #include "./stars/EAGLE/stars.h"
 #include "./stars/EAGLE/stars_iact.h"
-#elif defined(STARS_GEAR)
-#include "./stars/GEAR/stars.h"
-#include "./stars/GEAR/stars_iact.h"
 #else
 #error "Invalid choice of star model"
 #endif
diff --git a/src/stars/GEAR/stars.h b/src/stars/GEAR/stars.h
deleted file mode 100644
index 467aaa164ba9762d85f8dfae85db86ff76ae779e..0000000000000000000000000000000000000000
--- a/src/stars/GEAR/stars.h
+++ /dev/null
@@ -1,172 +0,0 @@
-/*******************************************************************************
- * This file is part of SWIFT.
- * Coypright (c) 2019 Loic Hausammann (loic.hausammann@epfl.ch)
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Lesser General Public License as published
- * by the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- *
- ******************************************************************************/
-#ifndef SWIFT_GEAR_STARS_H
-#define SWIFT_GEAR_STARS_H
-
-#include <float.h>
-#include "minmax.h"
-
-/**
- * @brief Computes the gravity time-step of a given star particle.
- *
- * @param sp Pointer to the s-particle data.
- */
-__attribute__((always_inline)) INLINE static float stars_compute_timestep(
-    const struct spart* const sp) {
-
-  return FLT_MAX;
-}
-
-/**
- * @brief Initialises the s-particles for the first time
- *
- * This function is called only once just after the ICs have been
- * read in to do some conversions.
- *
- * @param sp The particle to act upon
- * @param stars_properties The properties of the stellar model.
- */
-__attribute__((always_inline)) INLINE static void stars_first_init_spart(
-    struct spart* sp, const struct stars_props* stars_properties) {
-
-  sp->time_bin = 0;
-}
-
-/**
- * @brief Prepares a s-particle for its interactions
- *
- * @param sp The particle to act upon
- */
-__attribute__((always_inline)) INLINE static void stars_init_spart(
-    struct spart* sp) {
-
-#ifdef DEBUG_INTERACTIONS_STARS
-  for (int i = 0; i < MAX_NUM_OF_NEIGHBOURS_STARS; ++i)
-    sp->ids_ngbs_density[i] = -1;
-  sp->num_ngb_density = 0;
-#endif
-
-  sp->density.wcount = 0.f;
-  sp->density.wcount_dh = 0.f;
-}
-
-/**
- * @brief Predict additional particle fields forward in time when drifting
- *
- * @param sp The particle
- * @param dt_drift The drift time-step for positions.
- */
-__attribute__((always_inline)) INLINE static void stars_predict_extra(
-    struct spart* restrict sp, float dt_drift) {}
-
-/**
- * @brief Sets the values to be predicted in the drifts to their values at a
- * kick time
- *
- * @param sp The particle.
- */
-__attribute__((always_inline)) INLINE static void stars_reset_predicted_values(
-    struct spart* restrict sp) {}
-
-/**
- * @brief Finishes the calculation of (non-gravity) forces acting on stars
- *
- * @param sp The particle to act upon
- */
-__attribute__((always_inline)) INLINE static void stars_end_feedback(
-    struct spart* sp) {}
-
-/**
- * @brief Kick the additional variables
- *
- * @param sp The particle to act upon
- * @param dt The time-step for this kick
- */
-__attribute__((always_inline)) INLINE static void stars_kick_extra(
-    struct spart* sp, float dt) {}
-
-/**
- * @brief Finishes the calculation of density on stars
- *
- * @param sp The particle to act upon
- * @param cosmo The current cosmological model.
- */
-__attribute__((always_inline)) INLINE static void stars_end_density(
-    struct spart* sp, const struct cosmology* cosmo) {
-
-  /* Some smoothing length multiples. */
-  const float h = sp->h;
-  const float h_inv = 1.0f / h;                       /* 1/h */
-  const float h_inv_dim = pow_dimension(h_inv);       /* 1/h^d */
-  const float h_inv_dim_plus_one = h_inv_dim * h_inv; /* 1/h^(d+1) */
-
-  /* Finish the calculation by inserting the missing h-factors */
-  sp->density.wcount *= h_inv_dim;
-  sp->density.wcount_dh *= h_inv_dim_plus_one;
-}
-
-/**
- * @brief Sets all particle fields to sensible values when the #spart has 0
- * ngbs.
- *
- * @param sp The particle to act upon
- * @param cosmo The current cosmological model.
- */
-__attribute__((always_inline)) INLINE static void stars_spart_has_no_neighbours(
-    struct spart* restrict sp, const struct cosmology* cosmo) {
-
-  /* Some smoothing length multiples. */
-  const float h = sp->h;
-  const float h_inv = 1.0f / h;                 /* 1/h */
-  const float h_inv_dim = pow_dimension(h_inv); /* 1/h^d */
-
-  /* Re-set problematic values */
-  sp->density.wcount = kernel_root * h_inv_dim;
-  sp->density.wcount_dh = 0.f;
-}
-
-/**
- * @brief Reset acceleration fields of a particle
- *
- * This is the equivalent of hydro_reset_acceleration.
- * We do not compute the acceleration on star, therefore no need to use it.
- *
- * @param p The particle to act upon
- */
-__attribute__((always_inline)) INLINE static void stars_reset_feedback(
-    struct spart* restrict p) {
-
-#ifdef DEBUG_INTERACTIONS_STARS
-  for (int i = 0; i < MAX_NUM_OF_NEIGHBOURS_STARS; ++i)
-    p->ids_ngbs_force[i] = -1;
-  p->num_ngb_force = 0;
-#endif
-}
-
-/**
- * @brief Initializes constants related to stellar evolution, initializes imf,
- * reads and processes yield tables
- *
- * @param params swift_params parameters structure
- * @param stars stars_props data structure
- */
-inline static void stars_evolve_init(struct swift_params* params,
-                                     struct stars_props* restrict stars) {}
-
-#endif /* SWIFT_GEAR_STARS_H */
diff --git a/src/stars/GEAR/stars_debug.h b/src/stars/GEAR/stars_debug.h
deleted file mode 100644
index 41953367f6c8771ffd7460cee493c8330ecd874b..0000000000000000000000000000000000000000
--- a/src/stars/GEAR/stars_debug.h
+++ /dev/null
@@ -1,31 +0,0 @@
-/*******************************************************************************
- * This file is part of SWIFT.
- * Coypright (c) 2019 Loic Hausammann (loic.hausammann@epfl.ch)
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Lesser General Public License as published
- * by the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- *
- ******************************************************************************/
-#ifndef SWIFT_GEAR_STARS_DEBUG_H
-#define SWIFT_GEAR_STARS_DEBUG_H
-
-__attribute__((always_inline)) INLINE static void stars_debug_particle(
-    const struct spart* p) {
-  printf(
-      "x=[%.3e,%.3e,%.3e], "
-      "v_full=[%.3e,%.3e,%.3e] p->mass=%.3e \n t_begin=%d, t_end=%d\n",
-      p->x[0], p->x[1], p->x[2], p->v_full[0], p->v_full[1], p->v_full[2],
-      p->mass, p->ti_begin, p->ti_end);
-}
-
-#endif /* SWIFT_GEAR_STARS_DEBUG_H */
diff --git a/src/stars/GEAR/stars_iact.h b/src/stars/GEAR/stars_iact.h
deleted file mode 100644
index c7bda43fc0c66fcc890e6b05bacf871edfd10b5a..0000000000000000000000000000000000000000
--- a/src/stars/GEAR/stars_iact.h
+++ /dev/null
@@ -1,94 +0,0 @@
-/*******************************************************************************
- * This file is part of SWIFT.
- * Coypright (c) 2019 Loic Hausammann (loic.hausammann@epfl.ch)
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Lesser General Public License as published
- * by the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- *
- ******************************************************************************/
-#ifndef SWIFT_GEAR_STARS_IACT_H
-#define SWIFT_GEAR_STARS_IACT_H
-
-/**
- * @brief Density interaction between two particles (non-symmetric).
- *
- * @param r2 Comoving square distance between the two particles.
- * @param dx Comoving vector separating both particles (pi - pj).
- * @param hi Comoving smoothing-length of particle i.
- * @param hj Comoving smoothing-length of particle j.
- * @param si First sparticle.
- * @param pj Second particle (not updated).
- * @param a Current scale factor.
- * @param H Current Hubble parameter.
- */
-__attribute__((always_inline)) INLINE static void
-runner_iact_nonsym_stars_density(const float r2, const float *dx,
-                                 const float hi, const float hj,
-                                 struct spart *restrict si,
-                                 const struct part *restrict pj, const float a,
-                                 const float H) {
-
-  float wi, wi_dx;
-
-  /* Get r and 1/r. */
-  const float r_inv = 1.0f / sqrtf(r2);
-  const float r = r2 * r_inv;
-
-  /* Compute the kernel function */
-  const float hi_inv = 1.0f / hi;
-  const float ui = r * hi_inv;
-  kernel_deval(ui, &wi, &wi_dx);
-
-  /* Compute contribution to the number of neighbours */
-  si->density.wcount += wi;
-  si->density.wcount_dh -= (hydro_dimension * wi + ui * wi_dx);
-
-#ifdef DEBUG_INTERACTIONS_STARS
-  /* Update ngb counters */
-  if (si->num_ngb_density < MAX_NUM_OF_NEIGHBOURS_STARS)
-    si->ids_ngbs_density[si->num_ngb_density] = pj->id;
-
-  /* Update ngb counters */
-  ++si->num_ngb_density;
-#endif
-}
-
-/**
- * @brief Feedback interaction between two particles (non-symmetric).
- *
- * @param r2 Comoving square distance between the two particles.
- * @param dx Comoving vector separating both particles (pi - pj).
- * @param hi Comoving smoothing-length of particle i.
- * @param hj Comoving smoothing-length of particle j.
- * @param si First sparticle.
- * @param pj Second particle (not updated).
- * @param a Current scale factor.
- * @param H Current Hubble parameter.
- */
-__attribute__((always_inline)) INLINE static void
-runner_iact_nonsym_stars_feedback(const float r2, const float *dx,
-                                  const float hi, const float hj,
-                                  struct spart *restrict si,
-                                  struct part *restrict pj, const float a,
-                                  const float H) {
-#ifdef DEBUG_INTERACTIONS_STARS
-  /* Update ngb counters */
-  if (si->num_ngb_force < MAX_NUM_OF_NEIGHBOURS_STARS)
-    si->ids_ngbs_force[si->num_ngb_force] = pj->id;
-
-  /* Update ngb counters */
-  ++si->num_ngb_force;
-#endif
-}
-
-#endif
diff --git a/src/stars/GEAR/stars_io.h b/src/stars/GEAR/stars_io.h
deleted file mode 100644
index ebd72aa50a4194bf8c6f747e55d265ace0550c35..0000000000000000000000000000000000000000
--- a/src/stars/GEAR/stars_io.h
+++ /dev/null
@@ -1,248 +0,0 @@
-/*******************************************************************************
- * This file is part of SWIFT.
- * Coypright (c) 2019 Loic Hausammann (loic.hausammann@epfl.ch)
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Lesser General Public License as published
- * by the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- *
- ******************************************************************************/
-#ifndef SWIFT_GEAR_STARS_IO_H
-#define SWIFT_GEAR_STARS_IO_H
-
-#include "io_properties.h"
-#include "stars_part.h"
-
-/**
- * @brief Specifies which s-particle fields to read from a dataset
- *
- * @param sparts The s-particle array.
- * @param list The list of i/o properties to read.
- * @param num_fields The number of i/o fields to read.
- */
-INLINE static void stars_read_particles(struct spart *sparts,
-                                        struct io_props *list,
-                                        int *num_fields) {
-
-  /* Say how much we want to read */
-  *num_fields = 5;
-
-  /* List what we want to read */
-  list[0] = io_make_input_field("Coordinates", DOUBLE, 3, COMPULSORY,
-                                UNIT_CONV_LENGTH, sparts, x);
-  list[1] = io_make_input_field("Velocities", FLOAT, 3, COMPULSORY,
-                                UNIT_CONV_SPEED, sparts, v);
-  list[2] = io_make_input_field("Masses", FLOAT, 1, COMPULSORY, UNIT_CONV_MASS,
-                                sparts, mass);
-  list[3] = io_make_input_field("ParticleIDs", LONGLONG, 1, COMPULSORY,
-                                UNIT_CONV_NO_UNITS, sparts, id);
-  list[4] = io_make_input_field("SmoothingLength", FLOAT, 1, OPTIONAL,
-                                UNIT_CONV_LENGTH, sparts, h);
-}
-
-/**
- * @brief Specifies which s-particle fields to write to a dataset
- *
- * @param sparts The s-particle array.
- * @param list The list of i/o properties to write.
- * @param num_fields The number of i/o fields to write.
- * @param with_cosmology Is it a cosmological run?
- */
-INLINE static void stars_write_particles(const struct spart *sparts,
-                                         struct io_props *list, int *num_fields,
-                                         const int with_cosmology) {
-
-  /* Say how much we want to write */
-  *num_fields = 9;
-
-  /* List what we want to write */
-  list[0] =
-      io_make_output_field("Coordinates", DOUBLE, 3, UNIT_CONV_LENGTH, 1.,
-                           sparts, x, "Co-moving positions of the particles");
-
-  list[1] = io_make_output_field(
-      "Velocities", FLOAT, 3, UNIT_CONV_SPEED, 0.f, sparts, v,
-      "Peculiar velocities of the stars. This is (a * dx/dt) where x is the "
-      "co-moving positions of the particles");
-
-  list[2] = io_make_output_field("Masses", FLOAT, 1, UNIT_CONV_MASS, 0.f,
-                                 sparts, mass, "Masses of the particles");
-
-  list[3] =
-      io_make_output_field("ParticleIDs", LONGLONG, 1, UNIT_CONV_NO_UNITS, 0.f,
-                           sparts, id, "Unique IDs of the particles");
-
-  list[4] = io_make_output_field(
-      "SmoothingLength", FLOAT, 1, UNIT_CONV_LENGTH, 1.f, sparts, h,
-      "Co-moving smoothing lengths (FWHM of the kernel) of the particles");
-
-  if (with_cosmology) {
-    list[5] = io_make_output_field(
-        "BirthScaleFactors", FLOAT, 1, UNIT_CONV_NO_UNITS, 0.f, sparts,
-        birth_scale_factor, "Scale-factors at which the stars were born");
-  } else {
-    list[5] = io_make_output_field("BirthTimes", FLOAT, 1, UNIT_CONV_TIME, 0.f,
-                                   sparts, birth_time,
-                                   "Times at which the stars were born");
-  }
-
-  list[6] = io_make_output_field(
-      "BirthDensities", FLOAT, 1, UNIT_CONV_DENSITY, 0.f, sparts, birth.density,
-      "Physical densities at the time of birth of the gas particles that "
-      "turned into stars (note that "
-      "we store the physical density at the birth redshift, no conversion is "
-      "needed)");
-
-  list[7] =
-      io_make_output_field("BirthTemperatures", FLOAT, 1, UNIT_CONV_TEMPERATURE,
-                           0.f, sparts, birth.temperature,
-                           "Temperatures at the time of birth of the gas "
-                           "particles that turned into stars");
-
-  list[7] = io_make_output_field("BirthMasses", FLOAT, 1, UNIT_CONV_MASS, 0.f,
-                                 sparts, birth.mass,
-                                 "Masses of the star particles at birth time");
-
-#ifdef DEBUG_INTERACTIONS_STARS
-
-  list += *num_fields;
-  *num_fields += 4;
-
-  list[0] = io_make_output_field("Num_ngb_density", INT, 1, UNIT_CONV_NO_UNITS,
-                                 sparts, num_ngb_density);
-  list[1] = io_make_output_field("Num_ngb_force", INT, 1, UNIT_CONV_NO_UNITS,
-                                 sparts, num_ngb_force);
-  list[2] = io_make_output_field("Ids_ngb_density", LONGLONG,
-                                 MAX_NUM_OF_NEIGHBOURS_STARS,
-                                 UNIT_CONV_NO_UNITS, sparts, ids_ngbs_density);
-  list[3] = io_make_output_field("Ids_ngb_force", LONGLONG,
-                                 MAX_NUM_OF_NEIGHBOURS_STARS,
-                                 UNIT_CONV_NO_UNITS, sparts, ids_ngbs_force);
-#endif
-}
-
-/**
- * @brief Initialize the global properties of the stars scheme.
- *
- * By default, takes the values provided by the hydro.
- *
- * @param sp The #stars_props.
- * @param phys_const The physical constants in the internal unit system.
- * @param us The internal unit system.
- * @param params The parsed parameters.
- * @param p The already read-in properties of the hydro scheme.
- * @param cosmo The cosmological model.
- */
-INLINE static void stars_props_init(struct stars_props *sp,
-                                    const struct phys_const *phys_const,
-                                    const struct unit_system *us,
-                                    struct swift_params *params,
-                                    const struct hydro_props *p,
-                                    const struct cosmology *cosmo) {
-
-  /* Kernel properties */
-  sp->eta_neighbours = parser_get_opt_param_float(
-      params, "Stars:resolution_eta", p->eta_neighbours);
-
-  /* Tolerance for the smoothing length Newton-Raphson scheme */
-  sp->h_tolerance =
-      parser_get_opt_param_float(params, "Stars:h_tolerance", p->h_tolerance);
-
-  /* Get derived properties */
-  sp->target_neighbours = pow_dimension(sp->eta_neighbours) * kernel_norm;
-  const float delta_eta = sp->eta_neighbours * (1.f + sp->h_tolerance);
-  sp->delta_neighbours =
-      (pow_dimension(delta_eta) - pow_dimension(sp->eta_neighbours)) *
-      kernel_norm;
-
-  /* Number of iterations to converge h */
-  sp->max_smoothing_iterations = parser_get_opt_param_int(
-      params, "Stars:max_ghost_iterations", p->max_smoothing_iterations);
-
-  /* Time integration properties */
-  const float max_volume_change =
-      parser_get_opt_param_float(params, "Stars:max_volume_change", -1);
-  if (max_volume_change == -1)
-    sp->log_max_h_change = p->log_max_h_change;
-  else
-    sp->log_max_h_change = logf(powf(max_volume_change, hydro_dimension_inv));
-}
-
-/**
- * @brief Print the global properties of the stars scheme.
- *
- * @param sp The #stars_props.
- */
-INLINE static void stars_props_print(const struct stars_props *sp) {
-
-  /* Now stars */
-  message("Stars kernel: %s with eta=%f (%.2f neighbours).", kernel_name,
-          sp->eta_neighbours, sp->target_neighbours);
-
-  message("Stars relative tolerance in h: %.5f (+/- %.4f neighbours).",
-          sp->h_tolerance, sp->delta_neighbours);
-
-  message(
-      "Stars integration: Max change of volume: %.2f "
-      "(max|dlog(h)/dt|=%f).",
-      pow_dimension(expf(sp->log_max_h_change)), sp->log_max_h_change);
-
-  message("Maximal iterations in ghost task set to %d",
-          sp->max_smoothing_iterations);
-}
-
-#if defined(HAVE_HDF5)
-INLINE static void stars_props_print_snapshot(hid_t h_grpstars,
-                                              const struct stars_props *sp) {
-
-  io_write_attribute_s(h_grpstars, "Kernel function", kernel_name);
-  io_write_attribute_f(h_grpstars, "Kernel target N_ngb",
-                       sp->target_neighbours);
-  io_write_attribute_f(h_grpstars, "Kernel delta N_ngb", sp->delta_neighbours);
-  io_write_attribute_f(h_grpstars, "Kernel eta", sp->eta_neighbours);
-  io_write_attribute_f(h_grpstars, "Smoothing length tolerance",
-                       sp->h_tolerance);
-  io_write_attribute_f(h_grpstars, "Volume log(max(delta h))",
-                       sp->log_max_h_change);
-  io_write_attribute_f(h_grpstars, "Volume max change time-step",
-                       pow_dimension(expf(sp->log_max_h_change)));
-  io_write_attribute_i(h_grpstars, "Max ghost iterations",
-                       sp->max_smoothing_iterations);
-}
-#endif
-
-/**
- * @brief Write a #stars_props struct to the given FILE as a stream of bytes.
- *
- * @param p the struct
- * @param stream the file stream
- */
-INLINE static void stars_props_struct_dump(const struct stars_props *p,
-                                           FILE *stream) {
-  restart_write_blocks((void *)p, sizeof(struct stars_props), 1, stream,
-                       "starsprops", "stars props");
-}
-
-/**
- * @brief Restore a stars_props struct from the given FILE as a stream of
- * bytes.
- *
- * @param p the struct
- * @param stream the file stream
- */
-INLINE static void stars_props_struct_restore(const struct stars_props *p,
-                                              FILE *stream) {
-  restart_read_blocks((void *)p, sizeof(struct stars_props), 1, stream, NULL,
-                      "stars props");
-}
-
-#endif /* SWIFT_GEAR_STAR_IO_H */
diff --git a/src/stars/GEAR/stars_part.h b/src/stars/GEAR/stars_part.h
deleted file mode 100644
index bf68a580ef009f5a814fa17123301b5585d6084c..0000000000000000000000000000000000000000
--- a/src/stars/GEAR/stars_part.h
+++ /dev/null
@@ -1,154 +0,0 @@
-/*******************************************************************************
- * This file is part of SWIFT.
- * Coypright (c) 2019 Loic Hausammann (loic.hausammann@epfl.ch)
- *
- * This program is free software: you can redistribute it and/or modify
- * it under the terms of the GNU Lesser General Public License as published
- * by the Free Software Foundation, either version 3 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- * GNU General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public License
- * along with this program.  If not, see <http://www.gnu.org/licenses/>.
- *
- ******************************************************************************/
-#ifndef SWIFT_GEAR_STAR_PART_H
-#define SWIFT_GEAR_STAR_PART_H
-
-/* Some standard headers. */
-#include <stdlib.h>
-
-/* Read additional subgrid models */
-#include "chemistry_struct.h"
-#include "feedback_struct.h"
-#include "tracers_struct.h"
-
-/**
- * @brief Particle fields for the star particles.
- *
- * All quantities related to gravity are stored in the associate #gpart.
- */
-struct spart {
-
-  /*! Particle ID. */
-  long long id;
-
-  /*! Pointer to corresponding gravity part. */
-  struct gpart* gpart;
-
-  /*! Particle position. */
-  double x[3];
-
-  /* Offset between current position and position at last tree rebuild. */
-  float x_diff[3];
-
-  /* Offset between current position and position at last tree rebuild. */
-  float x_diff_sort[3];
-
-  /*! Particle velocity. */
-  float v[3];
-
-  /*! Star mass */
-  float mass;
-
-  /* Particle cutoff radius. */
-  float h;
-
-  /*! Union for the birth time and birth scale factor */
-  union {
-
-    /*! Birth time */
-    float birth_time;
-
-    /*! Birth scale factor */
-    float birth_scale_factor;
-  };
-
-  /*! Particle time bin */
-  timebin_t time_bin;
-
-  struct {
-
-    /* Number of neighbours. */
-    float wcount;
-
-    /* Number of neighbours spatial derivative. */
-    float wcount_dh;
-
-  } density;
-
-  struct {
-    /*! birth density*/
-    float density;
-
-    /*! birth temperature*/
-    float temperature;
-
-    /*! birth mass */
-    float mass;
-  } birth;
-
-  /*! Feedback structure */
-  struct feedback_spart_data feedback_data;
-
-  /*! Tracer structure */
-  struct tracers_xpart_data tracers_data;
-
-  /*! Chemistry structure */
-  struct chemistry_part_data chemistry_data;
-
-#ifdef SWIFT_DEBUG_CHECKS
-
-  /* Time of the last drift */
-  integertime_t ti_drift;
-
-  /* Time of the last kick */
-  integertime_t ti_kick;
-
-#endif
-
-#ifdef DEBUG_INTERACTIONS_STARS
-  /*! Number of interactions in the density SELF and PAIR */
-  int num_ngb_density;
-
-  /*! List of interacting particles in the density SELF and PAIR */
-  long long ids_ngbs_density[MAX_NUM_OF_NEIGHBOURS_STARS];
-
-  /*! Number of interactions in the force SELF and PAIR */
-  int num_ngb_force;
-
-  /*! List of interacting particles in the force SELF and PAIR */
-  long long ids_ngbs_force[MAX_NUM_OF_NEIGHBOURS_STARS];
-#endif
-
-} SWIFT_STRUCT_ALIGN;
-
-/**
- * @brief Contains all the constants and parameters of the stars scheme
- */
-struct stars_props {
-
-  /*! Resolution parameter */
-  float eta_neighbours;
-
-  /*! Target weightd number of neighbours (for info only)*/
-  float target_neighbours;
-
-  /*! Smoothing length tolerance */
-  float h_tolerance;
-
-  /*! Tolerance on neighbour number  (for info only)*/
-  float delta_neighbours;
-
-  /*! Maximal number of iterations to converge h */
-  int max_smoothing_iterations;
-
-  /*! Maximal change of h over one time-step */
-  float log_max_h_change;
-};
-
-#endif /* SWIFT_GEAR_STAR_PART_H */