Merge pull request #1510 from evoyiatzis/respa_class_2

Implementation of inner/middle/outer compute methods for lj/class2
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Axel Kohlmeyer 2019-06-17 14:13:47 -04:00 committed by GitHub
commit 5d73b0790f
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3 changed files with 322 additions and 12 deletions

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@ -155,9 +155,12 @@ All of the lj/class2 pair styles write their information to "binary
restart files"_restart.html, so pair_style and pair_coeff commands do
not need to be specified in an input script that reads a restart file.
All of the lj/class2 pair styles can only be used via the {pair}
keyword of the "run_style respa"_run_style.html command. They do not
support the {inner}, {middle}, {outer} keywords.
Only the {lj/class2} pair style support the use of the
{inner}, {middle}, and {outer} keywords of the "run_style
respa"_run_style.html command, meaning the pairwise forces can be
partitioned by distance at different levels of the rRESPA hierarchy.
The other styles only support the {pair} keyword of run_style respa.
See the "run_style"_run_style.html command for details.
[Restrictions:]

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@ -2,12 +2,10 @@
LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
http://lammps.sandia.gov, Sandia National Laboratories
Steve Plimpton, sjplimp@sandia.gov
Copyright (2003) Sandia Corporation. Under the terms of Contract
DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
certain rights in this software. This software is distributed under
the GNU General Public License.
See the README file in the top-level LAMMPS directory.
------------------------------------------------------------------------- */
@ -19,7 +17,12 @@
#include "atom.h"
#include "comm.h"
#include "force.h"
#include "neighbor.h"
#include "neigh_list.h"
#include "neigh_request.h"
#include "update.h"
#include "integrate.h"
#include "respa.h"
#include "math_const.h"
#include "memory.h"
#include "error.h"
@ -31,6 +34,7 @@ using namespace MathConst;
PairLJClass2::PairLJClass2(LAMMPS *lmp) : Pair(lmp)
{
respa_enable = 1;
writedata = 1;
}
@ -133,6 +137,270 @@ void PairLJClass2::compute(int eflag, int vflag)
if (vflag_fdotr) virial_fdotr_compute();
}
/* ----------------------------------------------------------------------
*/
void PairLJClass2::compute_inner()
{
int i,j,ii,jj,inum,jnum,itype,jtype;
double xtmp,ytmp,ztmp,delx,dely,delz,fpair;
double rsq,rinv,r2inv,r3inv,r6inv,forcelj,factor_lj,rsw;
int *ilist,*jlist,*numneigh,**firstneigh;
double **x = atom->x;
double **f = atom->f;
int *type = atom->type;
int nlocal = atom->nlocal;
double *special_lj = force->special_lj;
int newton_pair = force->newton_pair;
inum = list->inum_inner;
ilist = list->ilist_inner;
numneigh = list->numneigh_inner;
firstneigh = list->firstneigh_inner;
double cut_out_on = cut_respa[0];
double cut_out_off = cut_respa[1];
double cut_out_diff = cut_out_off - cut_out_on;
double cut_out_on_sq = cut_out_on*cut_out_on;
double cut_out_off_sq = cut_out_off*cut_out_off;
// loop over neighbors of my atoms
for (ii = 0; ii < inum; ii++) {
i = ilist[ii];
xtmp = x[i][0];
ytmp = x[i][1];
ztmp = x[i][2];
itype = type[i];
jlist = firstneigh[i];
jnum = numneigh[i];
for (jj = 0; jj < jnum; jj++) {
j = jlist[jj];
factor_lj = special_lj[sbmask(j)];
j &= NEIGHMASK;
delx = xtmp - x[j][0];
dely = ytmp - x[j][1];
delz = ztmp - x[j][2];
rsq = delx*delx + dely*dely + delz*delz;
if (rsq < cut_out_off_sq) {
r2inv = 1.0/rsq;
rinv = sqrt(r2inv);
r3inv = r2inv*rinv;
r6inv = r3inv*r3inv;
jtype = type[j];
forcelj = r6inv * (lj1[itype][jtype]*r3inv - lj2[itype][jtype]);
fpair = factor_lj*forcelj*r2inv;
if (rsq > cut_out_on_sq) {
rsw = (sqrt(rsq) - cut_out_on)/cut_out_diff;
fpair *= 1.0 - rsw*rsw*(3.0 - 2.0*rsw);
}
f[i][0] += delx*fpair;
f[i][1] += dely*fpair;
f[i][2] += delz*fpair;
if (newton_pair || j < nlocal) {
f[j][0] -= delx*fpair;
f[j][1] -= dely*fpair;
f[j][2] -= delz*fpair;
}
}
}
}
}
/* ---------------------------------------------------------------------- */
void PairLJClass2::compute_middle()
{
int i,j,ii,jj,inum,jnum,itype,jtype;
double xtmp,ytmp,ztmp,delx,dely,delz,fpair;
double rsq,rinv,r2inv,r3inv,r6inv,forcelj,factor_lj,rsw;
int *ilist,*jlist,*numneigh,**firstneigh;
double **x = atom->x;
double **f = atom->f;
int *type = atom->type;
int nlocal = atom->nlocal;
double *special_lj = force->special_lj;
int newton_pair = force->newton_pair;
inum = list->inum_middle;
ilist = list->ilist_middle;
numneigh = list->numneigh_middle;
firstneigh = list->firstneigh_middle;
double cut_in_off = cut_respa[0];
double cut_in_on = cut_respa[1];
double cut_out_on = cut_respa[2];
double cut_out_off = cut_respa[3];
double cut_in_diff = cut_in_on - cut_in_off;
double cut_out_diff = cut_out_off - cut_out_on;
double cut_in_off_sq = cut_in_off*cut_in_off;
double cut_in_on_sq = cut_in_on*cut_in_on;
double cut_out_on_sq = cut_out_on*cut_out_on;
double cut_out_off_sq = cut_out_off*cut_out_off;
// loop over neighbors of my atoms
for (ii = 0; ii < inum; ii++) {
i = ilist[ii];
xtmp = x[i][0];
ytmp = x[i][1];
ztmp = x[i][2];
itype = type[i];
jlist = firstneigh[i];
jnum = numneigh[i];
for (jj = 0; jj < jnum; jj++) {
j = jlist[jj];
factor_lj = special_lj[sbmask(j)];
j &= NEIGHMASK;
delx = xtmp - x[j][0];
dely = ytmp - x[j][1];
delz = ztmp - x[j][2];
rsq = delx*delx + dely*dely + delz*delz;
if (rsq < cut_out_off_sq && rsq > cut_in_off_sq) {
r2inv = 1.0/rsq;
rinv = sqrt(r2inv);
r3inv = r2inv*rinv;
r6inv = r3inv*r3inv;
jtype = type[j];
forcelj = r6inv * (lj1[itype][jtype]*r3inv - lj2[itype][jtype]);
fpair = factor_lj*forcelj*r2inv;
if (rsq < cut_in_on_sq) {
rsw = (sqrt(rsq) - cut_in_off)/cut_in_diff;
fpair *= rsw*rsw*(3.0 - 2.0*rsw);
}
if (rsq > cut_out_on_sq) {
rsw = (sqrt(rsq) - cut_out_on)/cut_out_diff;
fpair *= 1.0 + rsw*rsw*(2.0*rsw - 3.0);
}
f[i][0] += delx*fpair;
f[i][1] += dely*fpair;
f[i][2] += delz*fpair;
if (newton_pair || j < nlocal) {
f[j][0] -= delx*fpair;
f[j][1] -= dely*fpair;
f[j][2] -= delz*fpair;
}
}
}
}
}
/* ---------------------------------------------------------------------- */
void PairLJClass2::compute_outer(int eflag, int vflag)
{
int i,j,ii,jj,inum,jnum,itype,jtype;
double xtmp,ytmp,ztmp,delx,dely,delz,evdwl,fpair;
double rsq,rinv,r2inv,r3inv,r6inv,forcelj,factor_lj,rsw;
int *ilist,*jlist,*numneigh,**firstneigh;
evdwl = 0.0;
ev_init(eflag,vflag);
double **x = atom->x;
double **f = atom->f;
int *type = atom->type;
int nlocal = atom->nlocal;
double *special_lj = force->special_lj;
int newton_pair = force->newton_pair;
inum = list->inum;
ilist = list->ilist;
numneigh = list->numneigh;
firstneigh = list->firstneigh;
double cut_in_off = cut_respa[2];
double cut_in_on = cut_respa[3];
double cut_in_diff = cut_in_on - cut_in_off;
double cut_in_off_sq = cut_in_off*cut_in_off;
double cut_in_on_sq = cut_in_on*cut_in_on;
// loop over neighbors of my atoms
for (ii = 0; ii < inum; ii++) {
i = ilist[ii];
xtmp = x[i][0];
ytmp = x[i][1];
ztmp = x[i][2];
itype = type[i];
jlist = firstneigh[i];
jnum = numneigh[i];
for (jj = 0; jj < jnum; jj++) {
j = jlist[jj];
factor_lj = special_lj[sbmask(j)];
j &= NEIGHMASK;
delx = xtmp - x[j][0];
dely = ytmp - x[j][1];
delz = ztmp - x[j][2];
rsq = delx*delx + dely*dely + delz*delz;
jtype = type[j];
if (rsq < cutsq[itype][jtype]) {
if (rsq > cut_in_off_sq) {
r2inv = 1.0/rsq;
rinv = sqrt(r2inv);
r3inv = r2inv*rinv;
r6inv = r3inv*r3inv;
forcelj = r6inv * (lj1[itype][jtype]*r3inv - lj2[itype][jtype]);
fpair = factor_lj*forcelj*r2inv;
if (rsq < cut_in_on_sq) {
rsw = (sqrt(rsq) - cut_in_off)/cut_in_diff;
fpair *= rsw*rsw*(3.0 - 2.0*rsw);
}
f[i][0] += delx*fpair;
f[i][1] += dely*fpair;
f[i][2] += delz*fpair;
if (newton_pair || j < nlocal) {
f[j][0] -= delx*fpair;
f[j][1] -= dely*fpair;
f[j][2] -= delz*fpair;
}
}
if (eflag) {
r2inv = 1.0/rsq;
rinv = sqrt(r2inv);
r3inv = r2inv*rinv;
r6inv = r3inv*r3inv;
evdwl = r6inv*(lj3[itype][jtype]*r3inv-lj4[itype][jtype]) -
offset[itype][jtype];
evdwl *= factor_lj;
}
if (vflag) {
if (rsq <= cut_in_off_sq) {
r2inv = 1.0/rsq;
rinv = sqrt(r2inv);
r3inv = r2inv*rinv;
r6inv = r3inv*r3inv;
forcelj = r6inv * (lj1[itype][jtype]*r3inv - lj2[itype][jtype]);
fpair = factor_lj*forcelj*r2inv;
} else if (rsq < cut_in_on_sq)
fpair = factor_lj*forcelj*r2inv;
}
if (evflag) ev_tally(i,j,nlocal,newton_pair,
evdwl,0.0,fpair,delx,dely,delz);
}
}
}
}
/* ----------------------------------------------------------------------
allocate all arrays
------------------------------------------------------------------------- */
@ -212,6 +480,38 @@ void PairLJClass2::coeff(int narg, char **arg)
if (count == 0) error->all(FLERR,"Incorrect args for pair coefficients");
}
/* ----------------------------------------------------------------------
init specific to this pair style
------------------------------------------------------------------------- */
void PairLJClass2::init_style()
{
// request regular or rRESPA neighbor list
int irequest;
int respa = 0;
if (update->whichflag == 1 && strstr(update->integrate_style,"respa")) {
if (((Respa *) update->integrate)->level_inner >= 0) respa = 1;
if (((Respa *) update->integrate)->level_middle >= 0) respa = 2;
}
irequest = neighbor->request(this,instance_me);
if (respa >= 1) {
neighbor->requests[irequest]->respaouter = 1;
neighbor->requests[irequest]->respainner = 1;
}
if (respa == 2) neighbor->requests[irequest]->respamiddle = 1;
// set rRESPA cutoffs
if (strstr(update->integrate_style,"respa") &&
((Respa *) update->integrate)->level_inner >= 0)
cut_respa = ((Respa *) update->integrate)->cutoff;
else cut_respa = NULL;
}
/* ----------------------------------------------------------------------
init for one type pair i,j and corresponding j,i
------------------------------------------------------------------------- */
@ -246,6 +546,11 @@ double PairLJClass2::init_one(int i, int j)
lj4[j][i] = lj4[i][j];
offset[j][i] = offset[i][j];
// check interior rRESPA cutoff
if (cut_respa && cut[i][j] < cut_respa[3])
error->all(FLERR,"Pair cutoff < Respa interior cutoff");
// compute I,J contribution to long-range tail correction
// count total # of atoms of type I and J via Allreduce

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@ -2,12 +2,10 @@
LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
http://lammps.sandia.gov, Sandia National Laboratories
Steve Plimpton, sjplimp@sandia.gov
Copyright (2003) Sandia Corporation. Under the terms of Contract
DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
certain rights in this software. This software is distributed under
the GNU General Public License.
See the README file in the top-level LAMMPS directory.
------------------------------------------------------------------------- */
@ -31,6 +29,7 @@ class PairLJClass2 : public Pair {
virtual void compute(int, int);
virtual void settings(int, char **);
void coeff(int, char **);
void init_style();
virtual double init_one(int, int);
void write_restart(FILE *);
void read_restart(FILE *);
@ -41,11 +40,16 @@ class PairLJClass2 : public Pair {
double single(int, int, int, int, double, double, double, double &);
void *extract(const char *, int &);
void compute_inner();
void compute_middle();
void compute_outer(int, int);
protected:
double cut_global;
double **cut;
double **epsilon,**sigma;
double **lj1,**lj2,**lj3,**lj4,**offset;
double *cut_respa;
virtual void allocate();
};
@ -56,15 +60,13 @@ class PairLJClass2 : public Pair {
#endif
/* ERROR/WARNING messages:
E: Illegal ... command
Self-explanatory. Check the input script syntax and compare to the
documentation for the command. You can use -echo screen as a
command-line option when running LAMMPS to see the offending line.
E: Incorrect args for pair coefficients
Self-explanatory. Check the input script or data file.
E: Pair cutoff < Respa interior cutoff
One or more pairwise cutoffs are too short to use with the specified
rRESPA cutoffs.
*/