Page MenuHomec4science
Files F61356926

pair_lj_cut_thole_long.cpp
No OneTemporary
Actions

File Metadata

Created
Mon, May 6, 04:12

pair_lj_cut_thole_long.cpp
View Options

/* ----------------------------------------------------------------------
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.
------------------------------------------------------------------------- */
/* ----------------------------------------------------------------------
Contributing author: Paul Crozier (SNL)
------------------------------------------------------------------------- */
#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "pair_lj_cut_thole_long.h"
#include "atom.h"
#include "comm.h"
#include "force.h"
#include "kspace.h"
#include "update.h"
#include "integrate.h"
#include "neighbor.h"
#include "neigh_list.h"
#include "neigh_request.h"
#include "math_const.h"
#include "memory.h"
#include "error.h"
using namespace LAMMPS_NS;
using namespace MathConst;
#define EWALD_F 1.12837917
#define EWALD_P 9.95473818e-1
#define B0 -0.1335096380159268
#define B1 -2.57839507e-1
#define B2 -1.37203639e-1
#define B3 -8.88822059e-3
#define B4 -5.80844129e-3
#define B5 1.14652755e-1
/* ---------------------------------------------------------------------- */
PairLJCutTholeLong::PairLJCutTholeLong(LAMMPS *lmp) : Pair(lmp)
{
ewaldflag = pppmflag = 1;
writedata = 1;
ftable = NULL;
qdist = 0.0;
fix_drude = NULL;
}
/* ---------------------------------------------------------------------- */
PairLJCutTholeLong::~PairLJCutTholeLong()
{
if (allocated) {
memory->destroy(setflag);
memory->destroy(cutsq);
memory->destroy(polar);
memory->destroy(thole);
memory->destroy(ascreen);
memory->destroy(cut_lj);
memory->destroy(cut_ljsq);
memory->destroy(scale);
memory->destroy(epsilon);
memory->destroy(sigma);
memory->destroy(lj1);
memory->destroy(lj2);
memory->destroy(lj3);
memory->destroy(lj4);
memory->destroy(offset);
}
if (ftable) free_tables();
}
/* ---------------------------------------------------------------------- */
void PairLJCutTholeLong::compute(int eflag, int vflag)
{
int i,j,ii,jj,inum,jnum,itype,jtype,itable;
double qi,qj,xtmp,ytmp,ztmp,delx,dely,delz,ecoul,fpair,evdwl;
double r,rsq,r2inv,forcecoul,factor_coul,forcelj,factor_lj,r6inv;
double fraction,table;
double grij,expm2,prefactor,t,erfc,u;
int *ilist,*jlist,*numneigh,**firstneigh;
double factor_f,factor_e;
int di,dj;
double dqi,dqj,dcoul,asr,exp_asr;
int di_closest;
evdwl = ecoul = 0.0;
if (eflag || vflag) ev_setup(eflag,vflag);
else evflag = vflag_fdotr = 0;
double **x = atom->x;
double **f = atom->f;
double *q = atom->q;
int *type = atom->type;
int nlocal = atom->nlocal;
double *special_coul = force->special_coul;
double *special_lj = force->special_lj;
int newton_pair = force->newton_pair;
double qqrd2e = force->qqrd2e;
int *drudetype = fix_drude->drudetype;
tagint *drudeid = fix_drude->drudeid;
inum = list->inum;
ilist = list->ilist;
numneigh = list->numneigh;
firstneigh = list->firstneigh;
// loop over neighbors of my atoms
for (ii = 0; ii < inum; ii++) {
i = ilist[ii];
qi = q[i];
xtmp = x[i][0];
ytmp = x[i][1];
ztmp = x[i][2];
itype = type[i];
jlist = firstneigh[i];
jnum = numneigh[i];
if (drudetype[type[i]] != NOPOL_TYPE){
di = atom->map(drudeid[i]);
if (di < 0) error->all(FLERR, "Drude partner not found");
di_closest = domain->closest_image(i, di);
if (drudetype[type[i]] == CORE_TYPE)
dqi = -q[di];
else
dqi = qi;
}
for (jj = 0; jj < jnum; jj++) {
j = jlist[jj];
factor_lj = special_lj[sbmask(j)];
factor_coul = special_coul[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]) {
r2inv = 1.0/rsq;
if (rsq < cut_coulsq) {
qj = q[j];
r = sqrt(rsq);
if (!ncoultablebits || rsq <= tabinnersq) {
grij = g_ewald * r;
expm2 = exp(-grij*grij);
t = 1.0 / (1.0 + EWALD_P*grij);
u = 1. - t;
erfc = t * (1.+u*(B0+u*(B1+u*(B2+u*(B3+u*(B4+u*B5)))))) * expm2;
prefactor = qqrd2e * qi*qj/r;
forcecoul = prefactor * (erfc + EWALD_F*grij*expm2);
if (factor_coul < 1.0) forcecoul -= (1.0-factor_coul)*prefactor;
} else {
union_int_float_t rsq_lookup;
rsq_lookup.f = rsq;
itable = rsq_lookup.i & ncoulmask;
itable >>= ncoulshiftbits;
fraction = (rsq_lookup.f - rtable[itable]) * drtable[itable];
table = ftable[itable] + fraction*dftable[itable];
forcecoul = qi*qj * table;
if (factor_coul < 1.0) {
table = ctable[itable] + fraction*dctable[itable];
prefactor = qi*qj * table;
forcecoul -= (1.0-factor_coul)*prefactor;
}
}
if (drudetype[type[i]] != NOPOL_TYPE &&
drudetype[type[j]] != NOPOL_TYPE){
if (j != di_closest){
if (drudetype[type[j]] == CORE_TYPE){
dj = atom->map(drudeid[j]);
dqj = -q[dj];
} else dqj = qj;
asr = ascreen[type[i]][type[j]] * r;
exp_asr = exp(-asr);
dcoul = qqrd2e * dqi * dqj / r;
factor_f = 0.5*(2. + (exp_asr * (-2. - asr * (2. + asr))))
- factor_coul;
if (eflag) factor_e = 0.5*(2. - (exp_asr * (2. + asr)))
- factor_coul;
forcecoul += factor_f * dcoul;
}
}
} else forcecoul = 0.0;
if (rsq < cut_ljsq[itype][jtype]) {
r6inv = r2inv*r2inv*r2inv;
forcelj = r6inv * (lj1[itype][jtype]*r6inv - lj2[itype][jtype]);
} else forcelj = 0.0;
fpair = (forcecoul + factor_lj*forcelj) * r2inv;
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) {
if (rsq < cut_coulsq) {
if (!ncoultablebits || rsq <= tabinnersq)
ecoul = prefactor*erfc;
else {
table = etable[itable] + fraction*detable[itable];
ecoul = qi*qj * table;
}
if (factor_coul < 1.0) ecoul -= (1.0-factor_coul)*prefactor;
if (drudetype[type[i]] != NOPOL_TYPE &&
drudetype[type[j]] != NOPOL_TYPE && j != di_closest){
ecoul += factor_e * dcoul;
}
} else ecoul = 0.0;
if (rsq < cut_ljsq[itype][jtype]) {
evdwl = r6inv*(lj3[itype][jtype]*r6inv-lj4[itype][jtype]) -
offset[itype][jtype];
evdwl *= factor_lj;
} else evdwl = 0.0;
}
if (evflag) ev_tally(i,j,nlocal,newton_pair,
evdwl,ecoul,fpair,delx,dely,delz);
}
}
}
if (vflag_fdotr) virial_fdotr_compute();
}
/* ----------------------------------------------------------------------
allocate all arrays
------------------------------------------------------------------------- */
void PairLJCutTholeLong::allocate()
{
allocated = 1;
int n = atom->ntypes;
memory->create(setflag,n+1,n+1,"pair:setflag");
for (int i = 1; i <= n; i++)
for (int j = i; j <= n; j++)
setflag[i][j] = 0;
memory->create(cutsq,n+1,n+1,"pair:cutsq");
memory->create(cut_lj,n+1,n+1,"pair:cut_lj");
memory->create(cut_ljsq,n+1,n+1,"pair:cut_ljsq");
memory->create(scale,n+1,n+1,"pair:scale");
memory->create(ascreen,n+1,n+1,"pair:ascreen");
memory->create(thole,n+1,n+1,"pair:thole");
memory->create(polar,n+1,n+1,"pair:polar");
memory->create(epsilon,n+1,n+1,"pair:epsilon");
memory->create(sigma,n+1,n+1,"pair:sigma");
memory->create(lj1,n+1,n+1,"pair:lj1");
memory->create(lj2,n+1,n+1,"pair:lj2");
memory->create(lj3,n+1,n+1,"pair:lj3");
memory->create(lj4,n+1,n+1,"pair:lj4");
memory->create(offset,n+1,n+1,"pair:offset");
}
/* ----------------------------------------------------------------------
global settings
------------------------------------------------------------------------- */
void PairLJCutTholeLong::settings(int narg, char **arg)
{
if (narg < 2 || narg > 3) error->all(FLERR,"Illegal pair_style command");
thole_global = force->numeric(FLERR,arg[0]);
cut_lj_global = force->numeric(FLERR,arg[1]);
if (narg == 2) cut_coul = cut_lj_global;
else cut_coul = force->numeric(FLERR,arg[2]);
// reset cutoffs that have been explicitly set
if (allocated) {
int i,j;
for (i = 1; i <= atom->ntypes; i++)
for (j = i; j <= atom->ntypes; j++)
if (setflag[i][j]) {
thole[i][j] = thole_global;
cut_lj[i][j] = cut_lj_global;
}
}
}
/* ----------------------------------------------------------------------
set coeffs for one or more type pairs
------------------------------------------------------------------------- */
void PairLJCutTholeLong::coeff(int narg, char **arg)
{
if (narg < 5 || narg > 7)
error->all(FLERR,"Incorrect args for pair coefficients");
if (!allocated) allocate();
int ilo,ihi,jlo,jhi;
force->bounds(FLERR,arg[0],atom->ntypes,ilo,ihi);
force->bounds(FLERR,arg[1],atom->ntypes,jlo,jhi);
double epsilon_one = force->numeric(FLERR,arg[2]);
double sigma_one = force->numeric(FLERR,arg[3]);
double polar_one = force->numeric(FLERR,arg[4]);
double thole_one = thole_global;
if (narg >=6) thole_one = force->numeric(FLERR,arg[5]);
double cut_lj_one = cut_lj_global;
if (narg == 7) cut_lj_one = force->numeric(FLERR,arg[6]);
int count = 0;
for (int i = ilo; i <= ihi; i++) {
for (int j = MAX(jlo,i); j <= jhi; j++) {
epsilon[i][j] = epsilon_one;
sigma[i][j] = sigma_one;
polar[i][j] = polar_one;
thole[i][j] = thole_one;
ascreen[i][j] = thole[i][j] / pow(polar[i][j], 1./3.);
cut_lj[i][j] = cut_lj_one;
scale[i][j] = 1.0;
setflag[i][j] = 1;
count++;
}
}
if (count == 0) error->all(FLERR,"Incorrect args for pair coefficients");
}
/* ----------------------------------------------------------------------
init specific to this pair style
------------------------------------------------------------------------- */
void PairLJCutTholeLong::init_style()
{
if (!atom->q_flag)
error->all(FLERR,"Pair style lj/cut/thole/long requires atom attribute q");
int ifix;
for (ifix = 0; ifix < modify->nfix; ifix++)
if (strcmp(modify->fix[ifix]->style,"drude") == 0) break;
if (ifix == modify->nfix)
error->all(FLERR, "Pair style lj/cut/thole/long requires fix drude");
fix_drude = (FixDrude *) modify->fix[ifix];
int irequest = neighbor->request(this,instance_me);
cut_coulsq = cut_coul * cut_coul;
// set rRESPA cutoffs
cut_respa = NULL;
// insure use of KSpace long-range solver, set g_ewald
if (force->kspace == NULL)
error->all(FLERR,"Pair style requires a KSpace style");
g_ewald = force->kspace->g_ewald;
// setup force tables
if (ncoultablebits) init_tables(cut_coul,cut_respa);
}
/* ----------------------------------------------------------------------
init for one type pair i,j and corresponding j,i
------------------------------------------------------------------------- */
double PairLJCutTholeLong::init_one(int i, int j)
{
if (setflag[i][j] == 0) {
epsilon[i][j] = mix_energy(epsilon[i][i],epsilon[j][j],
sigma[i][i],sigma[j][j]);
sigma[i][j] = mix_distance(sigma[i][i],sigma[j][j]);
cut_lj[i][j] = mix_distance(cut_lj[i][i],cut_lj[j][j]);
polar[i][j] = sqrt(polar[i][i] * polar[j][j]);
thole[i][j] = 0.5 * (thole[i][i] + thole[j][j]);
ascreen[i][j] = thole[i][j] / pow(polar[i][j], 1./3.);
}
// include TIP4P qdist in full cutoff, qdist = 0.0 if not TIP4P
double cut = MAX(cut_lj[i][j],cut_coul+2.0*qdist);
cut_ljsq[i][j] = cut_lj[i][j] * cut_lj[i][j];
lj1[i][j] = 48.0 * epsilon[i][j] * pow(sigma[i][j],12.0);
lj2[i][j] = 24.0 * epsilon[i][j] * pow(sigma[i][j],6.0);
lj3[i][j] = 4.0 * epsilon[i][j] * pow(sigma[i][j],12.0);
lj4[i][j] = 4.0 * epsilon[i][j] * pow(sigma[i][j],6.0);
if (offset_flag && (cut_lj[i][j] > 0.0)) {
double ratio = sigma[i][j] / cut_lj[i][j];
offset[i][j] = 4.0 * epsilon[i][j] * (pow(ratio,12.0) - pow(ratio,6.0));
} else offset[i][j] = 0.0;
cut_ljsq[j][i] = cut_ljsq[i][j];
lj1[j][i] = lj1[i][j];
lj2[j][i] = lj2[i][j];
lj3[j][i] = lj3[i][j];
lj4[j][i] = lj4[i][j];
offset[j][i] = offset[i][j];
polar[j][i] = polar[i][j];
thole[j][i] = thole[i][j];
ascreen[j][i] = ascreen[i][j];
scale[j][i] = scale[i][j];
// check interior rRESPA cutoff
if (cut_respa && MIN(cut_lj[i][j],cut_coul) < 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
if (tail_flag) {
int *type = atom->type;
int nlocal = atom->nlocal;
double count[2],all[2];
count[0] = count[1] = 0.0;
for (int k = 0; k < nlocal; k++) {
if (type[k] == i) count[0] += 1.0;
if (type[k] == j) count[1] += 1.0;
}
MPI_Allreduce(count,all,2,MPI_DOUBLE,MPI_SUM,world);
double sig2 = sigma[i][j]*sigma[i][j];
double sig6 = sig2*sig2*sig2;
double rc3 = cut_lj[i][j]*cut_lj[i][j]*cut_lj[i][j];
double rc6 = rc3*rc3;
double rc9 = rc3*rc6;
etail_ij = 8.0*MY_PI*all[0]*all[1]*epsilon[i][j] *
sig6 * (sig6 - 3.0*rc6) / (9.0*rc9);
ptail_ij = 16.0*MY_PI*all[0]*all[1]*epsilon[i][j] *
sig6 * (2.0*sig6 - 3.0*rc6) / (9.0*rc9);
}
return cut;
}
/* ----------------------------------------------------------------------
proc 0 writes to restart file
------------------------------------------------------------------------- */
void PairLJCutTholeLong::write_restart(FILE *fp)
{
write_restart_settings(fp);
int i,j;
for (i = 1; i <= atom->ntypes; i++)
for (j = i; j <= atom->ntypes; j++) {
fwrite(&setflag[i][j],sizeof(int),1,fp);
if (setflag[i][j]) {
fwrite(&epsilon[i][j],sizeof(double),1,fp);
fwrite(&sigma[i][j],sizeof(double),1,fp);
fwrite(&polar[i][j],sizeof(double),1,fp);
fwrite(&thole[i][j],sizeof(double),1,fp);
fwrite(&cut_lj[i][j],sizeof(double),1,fp);
}
}
}
/* ----------------------------------------------------------------------
proc 0 reads from restart file, bcasts
------------------------------------------------------------------------- */
void PairLJCutTholeLong::read_restart(FILE *fp)
{
read_restart_settings(fp);
allocate();
int i,j;
int me = comm->me;
for (i = 1; i <= atom->ntypes; i++)
for (j = i; j <= atom->ntypes; j++) {
if (me == 0) fread(&setflag[i][j],sizeof(int),1,fp);
MPI_Bcast(&setflag[i][j],1,MPI_INT,0,world);
if (setflag[i][j]) {
if (me == 0) {
fread(&epsilon[i][j],sizeof(double),1,fp);
fread(&sigma[i][j],sizeof(double),1,fp);
fread(&polar[i][j],sizeof(double),1,fp);
fread(&thole[i][j],sizeof(double),1,fp);
ascreen[i][j] = thole[i][j] / pow(polar[i][j], 1./3.);
fread(&cut_lj[i][j],sizeof(double),1,fp);
}
MPI_Bcast(&epsilon[i][j],1,MPI_DOUBLE,0,world);
MPI_Bcast(&sigma[i][j],1,MPI_DOUBLE,0,world);
MPI_Bcast(&polar[i][j],1,MPI_DOUBLE,0,world);
MPI_Bcast(&thole[i][j],1,MPI_DOUBLE,0,world);
MPI_Bcast(&ascreen[i][j],1,MPI_DOUBLE,0,world);
MPI_Bcast(&cut_lj[i][j],1,MPI_DOUBLE,0,world);
}
}
}
/* ----------------------------------------------------------------------
proc 0 writes to restart file
------------------------------------------------------------------------- */
void PairLJCutTholeLong::write_restart_settings(FILE *fp)
{
fwrite(&cut_lj_global,sizeof(double),1,fp);
fwrite(&cut_coul,sizeof(double),1,fp);
fwrite(&thole_global,sizeof(double),1,fp);
fwrite(&cut_global,sizeof(double),1,fp);
fwrite(&offset_flag,sizeof(int),1,fp);
fwrite(&mix_flag,sizeof(int),1,fp);
fwrite(&tail_flag,sizeof(int),1,fp);
fwrite(&ncoultablebits,sizeof(int),1,fp);
fwrite(&tabinner,sizeof(double),1,fp);
}
/* ----------------------------------------------------------------------
proc 0 reads from restart file, bcasts
------------------------------------------------------------------------- */
void PairLJCutTholeLong::read_restart_settings(FILE *fp)
{
if (comm->me == 0) {
fread(&cut_lj_global,sizeof(double),1,fp);
fread(&cut_coul,sizeof(double),1,fp);
fread(&thole_global,sizeof(double),1,fp);
fread(&cut_global,sizeof(double),1,fp);
fread(&offset_flag,sizeof(int),1,fp);
fread(&mix_flag,sizeof(int),1,fp);
fread(&tail_flag,sizeof(int),1,fp);
fread(&ncoultablebits,sizeof(int),1,fp);
fread(&tabinner,sizeof(double),1,fp);
}
MPI_Bcast(&cut_lj_global,1,MPI_DOUBLE,0,world);
MPI_Bcast(&cut_coul,1,MPI_DOUBLE,0,world);
MPI_Bcast(&thole_global,1,MPI_DOUBLE,0,world);
MPI_Bcast(&cut_global,1,MPI_DOUBLE,0,world);
MPI_Bcast(&offset_flag,1,MPI_INT,0,world);
MPI_Bcast(&mix_flag,1,MPI_INT,0,world);
MPI_Bcast(&tail_flag,1,MPI_INT,0,world);
MPI_Bcast(&ncoultablebits,1,MPI_INT,0,world);
MPI_Bcast(&tabinner,1,MPI_DOUBLE,0,world);
}
/* ----------------------------------------------------------------------
proc 0 writes to data file
------------------------------------------------------------------------- */
void PairLJCutTholeLong::write_data(FILE *fp)
{
for (int i = 1; i <= atom->ntypes; i++)
fprintf(fp,"%d %g %g %g %g\n",i,epsilon[i][i],sigma[i][i],polar[i][i],thole[i][i]);
}
/* ----------------------------------------------------------------------
proc 0 writes all pairs to data file
------------------------------------------------------------------------- */
void PairLJCutTholeLong::write_data_all(FILE *fp)
{
for (int i = 1; i <= atom->ntypes; i++)
for (int j = i; j <= atom->ntypes; j++)
fprintf(fp,"%d %d %g %g %g %g %g\n",i,j,epsilon[i][j],sigma[i][j],polar[i][j],thole[i][j],cut_lj[i][j]);
}
/* ---------------------------------------------------------------------- */
double PairLJCutTholeLong::single(int i, int j, int itype, int jtype,
double rsq, double factor_coul,
double factor_lj, double &fforce)
{
double r2inv,r6inv,r,grij,expm2,t,erfc,prefactor,u;
double fraction,table,forcecoul,forcelj,phicoul,philj;
int itable;
double factor_f,factor_e;
double dqi,dqj,dcoul,asr,exp_asr;
int di, dj, di_closest;
int *drudetype = fix_drude->drudetype;
tagint *drudeid = fix_drude->drudeid;
int *type = atom->type;
r2inv = 1.0/rsq;
if (rsq < cut_coulsq) {
r = sqrt(rsq);
if (!ncoultablebits || rsq <= tabinnersq) {
grij = g_ewald * r;
expm2 = exp(-grij*grij);
t = 1.0 / (1.0 + EWALD_P*grij);
u = 1. - t;
erfc = t * (1.+u*(B0+u*(B1+u*(B2+u*(B3+u*(B4+u*B5)))))) * expm2;
prefactor = force->qqrd2e * atom->q[i]*atom->q[j]/r;
forcecoul = prefactor * (erfc + EWALD_F*grij*expm2);
if (factor_coul < 1.0) forcecoul -= (1.0-factor_coul)*prefactor;
} else {
union_int_float_t rsq_lookup_single;
rsq_lookup_single.f = rsq;
itable = rsq_lookup_single.i & ncoulmask;
itable >>= ncoulshiftbits;
fraction = (rsq_lookup_single.f - rtable[itable]) * drtable[itable];
table = ftable[itable] + fraction*dftable[itable];
forcecoul = atom->q[i]*atom->q[j] * table;
if (factor_coul < 1.0) {
table = ctable[itable] + fraction*dctable[itable];
prefactor = atom->q[i]*atom->q[j] * table;
forcecoul -= (1.0-factor_coul)*prefactor;
}
}
if (drudetype[type[i]] != NOPOL_TYPE && drudetype[type[j]] != NOPOL_TYPE) {
di = atom->map(drudeid[i]);
di_closest = domain->closest_image(i, di);
if (j != di_closest){
if (drudetype[i] == CORE_TYPE) dqi = -atom->q[di];
else if (drudetype[i] == DRUDE_TYPE) dqi = atom->q[i];
else dqi = 0.0;
if (drudetype[j] == CORE_TYPE) {
dj = atom->map(drudeid[j]);
dqj = -atom->q[dj];
} else if (drudetype[j] == DRUDE_TYPE) dqj = atom->q[j];
else dqj = 0.0;
asr = ascreen[itype][jtype] * r;
exp_asr = exp(-asr);
dcoul = force->qqrd2e * dqi * dqj / r;
factor_f = 0.5*(2. + (exp_asr * (-2. - asr * (2. + asr))))
- factor_coul;
forcecoul += factor_f * dcoul;
factor_e = 0.5*(2. - (exp_asr * (2. + asr))) - factor_coul;
}
}
} else forcecoul = 0.0;
if (rsq < cut_ljsq[itype][jtype]) {
r6inv = r2inv*r2inv*r2inv;
forcelj = r6inv * (lj1[itype][jtype]*r6inv - lj2[itype][jtype]);
} else forcelj = 0.0;
fforce = (forcecoul + factor_lj*forcelj) * r2inv;
double eng = 0.0;
if (rsq < cut_coulsq) {
if (!ncoultablebits || rsq <= tabinnersq)
phicoul = prefactor*erfc;
else {
table = etable[itable] + fraction*detable[itable];
phicoul = atom->q[i]*atom->q[j] * table;
}
if (factor_coul < 1.0) phicoul -= (1.0-factor_coul)*prefactor;
if (drudetype[type[i]] != NOPOL_TYPE && drudetype[type[j]] != NOPOL_TYPE &&
di_closest != j)
phicoul += factor_e * dcoul;
eng += phicoul;
}
if (rsq < cut_ljsq[itype][jtype]) {
philj = r6inv*(lj3[itype][jtype]*r6inv-lj4[itype][jtype]) -
offset[itype][jtype];
eng += factor_lj*philj;
}
return eng;
}
/* ---------------------------------------------------------------------- */
void *PairLJCutTholeLong::extract(const char *str, int &dim)
{
dim = 0;
if (strcmp(str,"cut_coul") == 0) return (void *) &cut_coul;
dim = 6;
if (strcmp(str,"epsilon") == 0) return (void *) epsilon;
if (strcmp(str,"sigma") == 0) return (void *) sigma;
if (strcmp(str,"scale") == 0) return (void *) scale;
if (strcmp(str,"polar") == 0) return (void *) polar;
if (strcmp(str,"thole") == 0) return (void *) thole;
if (strcmp(str,"ascreen") == 0) return (void *) ascreen;
return NULL;
}

Event Timeline

c4science · Help