diff --git a/src/gravity/ExternalPotential/gravity.h b/src/gravity/ExternalPotential/gravity.h
deleted file mode 100644
index 82bc52ad3e05794c8c05896075edc463a69197ff..0000000000000000000000000000000000000000
--- a/src/gravity/ExternalPotential/gravity.h
+++ /dev/null
@@ -1,35 +0,0 @@
-/*******************************************************************************
- * This file is part of SWIFT.
- * Coypright (c) 2015 Matthieu Schaller (matthieu.schaller@durham.ac.uk)
- *
- * 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/>.
- *
- ******************************************************************************/
-
-#include <float.h>
-
-/**
- * @brief Computes the gravity time-step of a given particle
- *
- * @param p Pointer to the particle data
- * @param xp Pointer to the extended particle data
- *
- */
-
-__attribute__((always_inline)) INLINE static float gravity_compute_timestep(
- struct part* p, struct xpart* xp) {
-
- /* Currently no limit is imposed */
- return FLT_MAX;
-}
diff --git a/src/gravity/ExternalPotential/gravity_io.h b/src/gravity/ExternalPotential/gravity_io.h
deleted file mode 100644
index 796d24a93dba5f051362c413edf3dd5c11d17239..0000000000000000000000000000000000000000
--- a/src/gravity/ExternalPotential/gravity_io.h
+++ /dev/null
@@ -1,71 +0,0 @@
-/*******************************************************************************
- * This file is part of SWIFT.
- * Coypright (c) 2016 Matthieu Schaller (matthieu.schaller@durham.ac.uk)
- *
- * 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/>.
- *
- ******************************************************************************/
-
-/**
- * @brief Reads the different particles to the HDF5 file
- *
- * @param h_grp The HDF5 group in which to read the arrays.
- * @param N The number of particles on that MPI rank.
- * @param N_total The total number of particles (only used in MPI mode)
- * @param offset The offset of the particles for this MPI rank (only used in MPI
- *mode)
- * @param parts The particle array
- *
- */
-__attribute__((always_inline)) INLINE static void darkmatter_read_particles(
- hid_t h_grp, int N, long long N_total, long long offset,
- struct gpart* gparts) {
- message("Reading Dark Matter particles\n");
- /* Read arrays */
- readArray(h_grp, "Coordinates", DOUBLE, N, 3, gparts, N_total, offset, x,
- COMPULSORY);
- readArray(h_grp, "Velocities", FLOAT, N, 3, gparts, N_total, offset, v,
- COMPULSORY);
- readArray(h_grp, "ParticleIDs", ULONGLONG, N, 1, gparts, N_total, offset, id,
- COMPULSORY);
-}
-
-/**
- * @brief Writes the different particles to the HDF5 file
- *
- * @param h_grp The HDF5 group in which to write the arrays.
- * @param fileName The name of the file (unsued in MPI mode).
- * @param xmfFile The XMF file to write to (unused in MPI mode).
- * @param N The number of particles on that MPI rank.
- * @param N_total The total number of particles (only used in MPI mode)
- * @param mpi_rank The MPI rank of this node (only used in MPI mode)
- * @param offset The offset of the particles for this MPI rank (only used in MPI
- *mode)
- * @param parts The particle array
- * @param us The unit system to use
- *
- */
-__attribute__((always_inline)) INLINE static void darkmatter_write_particles(
- hid_t h_grp, char* fileName, FILE* xmfFile, int N, long long N_total,
- int mpi_rank, long long offset, struct gpart* gparts, struct UnitSystem* us) {
-
- /* Write arrays */
- writeArray(h_grp, fileName, xmfFile, "Coordinates", DOUBLE, N, 3, gparts,
- N_total, mpi_rank, offset, x, us, UNIT_CONV_LENGTH);
- writeArray(h_grp, fileName, xmfFile, "Velocities", FLOAT, N, 3, gparts,
- N_total, mpi_rank, offset, v, us, UNIT_CONV_SPEED);
- writeArray(h_grp, fileName, xmfFile, "ParticleIDs", ULONGLONG, N, 1, gparts,
- N_total, mpi_rank, offset, id, us, UNIT_CONV_NO_UNITS);
-}
-
diff --git a/src/gravity/ExternalPotential/gravity_part.h b/src/gravity/ExternalPotential/gravity_part.h
deleted file mode 100644
index da3595fb89dc499cb5f8eb1aea15108544dc5ac4..0000000000000000000000000000000000000000
--- a/src/gravity/ExternalPotential/gravity_part.h
+++ /dev/null
@@ -1,73 +0,0 @@
-/*******************************************************************************
- * This file is part of SWIFT.
- * Copyright (c) 2012 Pedro Gonnet (pedro.gonnet@durham.ac.uk)
- *
- * 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_GPART_H
-#define SWIFT_GPART_H
-
-/* Some standard headers. */
-#include <stdlib.h>
-
-#ifdef DONOTUSEYET
-/* properties of external potential */
-static struct ExternalPointMass
-{
- const float Mass;
- const float Position[3];
-} PointMass = {.Mass = 1, .Position={0.,0.,0.}};
-#endif
-
-/* Gravity particle. */
-struct gpart {
-
- /* Particle position. */
- double x[3];
-
- /* Particle velocity. */
- float v_full[3];
-
- /* Particle acceleration. */
- float a[3];
-
- /* Particle external gravity acceleration */
- float a_grav_external[3];
-
- /* Particle mass. */
- float mass;
-
- /* Particle time of beginning of time-step. */
- int ti_begin;
-
- /* Particle time of end of time-step. */
- int ti_end;
-
- /* current time of x, and of v_full */
- float tx;
- float tv;
-
- /* Anonymous union for id/part. */
- union {
-
- /* Particle ID. By default: gravity only particles have a negative ID*/
- long long id;
-
- /* Pointer to corresponding SPH part. */
- struct part* part;
- };
-
-} __attribute__((aligned(part_align)));
-#endif /* SWIFT_GPART_H */
diff --git a/src/gravity/ExternalPotential/runner_iact_grav.h b/src/gravity/ExternalPotential/runner_iact_grav.h
deleted file mode 100644
index 16ea59c599b0352cd8add7a5efa1a3dbdbfb91c1..0000000000000000000000000000000000000000
--- a/src/gravity/ExternalPotential/runner_iact_grav.h
+++ /dev/null
@@ -1,123 +0,0 @@
-/*******************************************************************************
- * This file is part of SWIFT.
- * Copyright (c) 2013 Pedro Gonnet (pedro.gonnet@durham.ac.uk)
- * Matthieu Schaller (matthieu.schaller@durham.ac.uk)
- *
- * 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_RUNNER_IACT_GRAV_H
-#define SWIFT_RUNNER_IACT_GRAV_H
-
-/* Includes. */
-#include "const.h"
-#include "kernel.h"
-#include "vector.h"
-
-/**
- * @file runner_iact_grav.c
- * @brief Gravity interaction functions.
- *
- */
-
-/**
- * @brief Gravity potential
- */
-
-__attribute__((always_inline)) INLINE static void runner_iact_grav(
- float r2, float *dx, struct gpart *pi, struct gpart *pj) {
-
- float ir, r;
- float w, acc;
- float mi = pi->mass, mj = pj->mass;
- int k;
-
- /* Get the absolute distance. */
- ir = 1.0f / sqrtf(r2);
- r = r2 * ir;
-
- /* Evaluate the gravity kernel. */
- kernel_grav_eval(r, &acc);
-
- /* Scale the acceleration. */
- acc *= const_G * ir * ir * ir;
-
- /* Aggregate the accelerations. */
- for (k = 0; k < 3; k++) {
- w = acc * dx[k];
- pi->a[k] -= w * mj;
- pj->a[k] += w * mi;
- }
-}
-
-/**
- * @brief Gravity potential (Vectorized version)
- */
-__attribute__((always_inline)) INLINE static void runner_iact_vec_grav(
- float *R2, float *Dx, struct gpart **pi, struct gpart **pj) {
-
-#ifdef VECTORIZE
-
- vector ir, r, r2, dx[3];
- vector w, acc, ai, aj;
- vector mi, mj;
- int j, k;
-
-#if VEC_SIZE == 8
- mi.v = vec_set(pi[0]->mass, pi[1]->mass, pi[2]->mass, pi[3]->mass,
- pi[4]->mass, pi[5]->mass, pi[6]->mass, pi[7]->mass);
- mj.v = vec_set(pj[0]->mass, pj[1]->mass, pj[2]->mass, pj[3]->mass,
- pj[4]->mass, pj[5]->mass, pj[6]->mass, pj[7]->mass);
- for (k = 0; k < 3; k++)
- dx[k].v = vec_set(Dx[0 + k], Dx[3 + k], Dx[6 + k], Dx[9 + k], Dx[12 + k],
- Dx[15 + k], Dx[18 + k], Dx[21 + k]);
-#elif VEC_SIZE == 4
- mi.v = vec_set(pi[0]->mass, pi[1]->mass, pi[2]->mass, pi[3]->mass);
- mj.v = vec_set(pj[0]->mass, pj[1]->mass, pj[2]->mass, pj[3]->mass);
- for (k = 0; k < 3; k++)
- dx[k].v = vec_set(Dx[0 + k], Dx[3 + k], Dx[6 + k], Dx[9 + k]);
-#endif
-
- /* Get the radius and inverse radius. */
- r2.v = vec_load(R2);
- ir.v = vec_rsqrt(r2.v);
- ir.v = ir.v - vec_set1(0.5f) * ir.v * (r2.v * ir.v * ir.v - vec_set1(1.0f));
- r.v = r2.v * ir.v;
-
- /* Evaluate the gravity kernel. */
- blender_eval_vec(&r, &acc);
-
- /* Scale the acceleration. */
- acc.v *= vec_set1(const_G) * ir.v * ir.v * ir.v;
-
- /* Aggregate the accelerations. */
- for (k = 0; k < 3; k++) {
- w.v = acc.v * dx[k].v;
- ai.v = w.v * mj.v;
- aj.v = w.v * mi.v;
- for (j = 0; j < VEC_SIZE; j++) {
- pi[j]->a[k] -= ai.f[j];
- pj[j]->a[k] += aj.f[j];
- }
- }
-
-#else
-
- for (int k = 0; k < VEC_SIZE; k++)
- runner_iact_grav(R2[k], &Dx[3 * k], pi[k], pj[k]);
-
-#endif
-}
-
-#endif /* SWIFT_RUNNER_IACT_GRAV_H */