In which part of the resource codes of LAMMPS Mixing, shift, table, tail correction, restart , rRESPA capabilities are set?

LAMMPS LAMMPS Development
1

Hi,
As you know, some pair_styles have the capabilities of Mixing, shift, table, tail correction, restart, and rRESPA. I want to know in which part of the resource codes of LAMMPS these capabilities are set and determined. This is because we are developing a new pair_style which have some similarities with Gay-Berne. So we want to use the Gay-Berne codes as a basis for developing our pair_style. But for the mentioned capabilities we have to know how and where they are introduced in the LAMMPS resource codes.
Any comment will be appreciated.
Regards,
Mehdi,

2

Within the pair style. Please look for example at the lj/cut pair style (which is a bit like the Drosophila fly for MD simulations. Specifically:

  • mixing is realized in the init_one function (indicated by setflag[i][j] == 0, i.e. unset between types i and j)
  • similarly computing the energy offset for shifting the potential to zero at cutoff (the request is indicated by offset_flag)
  • also the tail correction is computed in that function (see tail_flag)
  • for supporting r-RESPA in general, nothing needs to be done. Only if you want to support multi-cutoff r-RESPA for your pair style. In that case you need to request a r-RESPA style neighbor list in the init_style() function, set the respa_enable flag to 1 in the pair style constructor, and implement the compute_inner(), compute_middle() and compute_outer() functions in addition to the compute() function
  • the pair_modify table option only applies to long-range coulomb. You can study pair style coul/long for that (look for ncoultablebits)
  • for restart capabilities you need to implement the functions for reading and writing global and per-type settings
3

Many thanks for your nice and prompt answers. :ok_hand:
Lets apply them and back to you if encountered problem.