Check if there are any active particles within interaction distance and return if there are not. Only populate the cache from the first particle in a cell that interacts*and* is also active.

Perform padding of the cache when populating it instead of on the fly. Create fake particles to be maxed out in the inner interaction loop.

Fixed bug with finding the exit iteration of the inner loops, -1 and +1 to value. Replaced vec_load with vec_unaligned_load for GCC. Pad cache correctly when the number of iterations of the inner loop is not a multiple of the vector length.

Added function to populate max_d arrays without the cache and to find the first and last particles in ci and cj that interact with neighbouring cell.

Added statistics to runner_dopair1_vec to find the total number of interactions for each cell pair orientation.

Re-added version of dopair1_vec that does not process 2 pi at the same time and use 2 vectors for interaction loop.

Corrected 2nd loop limits in dopair1_density_vec_2 and added new version that will only read one cell into the cache at a time.

Added dopair1 version to use an unsorted cache. Improved sorted cache version by processing 2 pi at a time.

Fixed bug with intrinsic dopair1. Break in search loop and there is no need to pad cache and check for r2>0 in dopair as particles past the threshold will return false in r2<hig2.