1017 lines
36 KiB
C++
1017 lines
36 KiB
C++
/* ----------------------------------------------------------------------
|
|
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: Pieter J. in 't Veld (SNL)
|
|
Tabulation for long-range dispersion added by Wayne Mitchell (Loyola
|
|
University New Orleans)
|
|
------------------------------------------------------------------------- */
|
|
|
|
#include "pair_lj_long_coul_long.h"
|
|
|
|
#include <cmath>
|
|
#include <cstring>
|
|
#include "math_vector.h"
|
|
#include "atom.h"
|
|
#include "comm.h"
|
|
#include "neighbor.h"
|
|
#include "neigh_list.h"
|
|
#include "neigh_request.h"
|
|
#include "force.h"
|
|
#include "kspace.h"
|
|
#include "update.h"
|
|
#include "respa.h"
|
|
#include "memory.h"
|
|
#include "error.h"
|
|
|
|
|
|
|
|
using namespace LAMMPS_NS;
|
|
|
|
#define EWALD_F 1.12837917
|
|
#define EWALD_P 0.3275911
|
|
#define A1 0.254829592
|
|
#define A2 -0.284496736
|
|
#define A3 1.421413741
|
|
#define A4 -1.453152027
|
|
#define A5 1.061405429
|
|
|
|
/* ---------------------------------------------------------------------- */
|
|
|
|
PairLJLongCoulLong::PairLJLongCoulLong(LAMMPS *lmp) : Pair(lmp)
|
|
{
|
|
dispersionflag = ewaldflag = pppmflag = 1;
|
|
respa_enable = 1;
|
|
writedata = 1;
|
|
ftable = NULL;
|
|
fdisptable = NULL;
|
|
qdist = 0.0;
|
|
cut_respa = NULL;
|
|
}
|
|
|
|
/* ----------------------------------------------------------------------
|
|
global settings
|
|
------------------------------------------------------------------------- */
|
|
|
|
void PairLJLongCoulLong::options(char **arg, int order)
|
|
{
|
|
const char *option[] = {"long", "cut", "off", NULL};
|
|
int i;
|
|
|
|
if (!*arg) error->all(FLERR,"Illegal pair_style lj/long/coul/long command");
|
|
for (i=0; option[i]&&strcmp(arg[0], option[i]); ++i);
|
|
switch (i) {
|
|
case 0: ewald_order |= 1<<order; break;
|
|
case 2: ewald_off |= 1<<order; break;
|
|
case 1: break;
|
|
default: error->all(FLERR,"Illegal pair_style lj/long/coul/long command");
|
|
}
|
|
}
|
|
|
|
void PairLJLongCoulLong::settings(int narg, char **arg)
|
|
{
|
|
if (narg != 3 && narg != 4) error->all(FLERR,"Illegal pair_style command");
|
|
|
|
ewald_order = 0;
|
|
ewald_off = 0;
|
|
|
|
options(arg,6);
|
|
options(++arg,1);
|
|
|
|
if (!comm->me && ewald_order == ((1<<1) | (1<<6)))
|
|
error->warning(FLERR,"Using largest cutoff for lj/long/coul/long");
|
|
if (!*(++arg))
|
|
error->all(FLERR,"Cutoffs missing in pair_style lj/long/coul/long");
|
|
if (!((ewald_order^ewald_off) & (1<<6)))
|
|
dispersionflag = 0;
|
|
if (!((ewald_order^ewald_off) & (1<<1)))
|
|
error->all(FLERR,
|
|
"Coulomb cut not supported in pair_style lj/long/coul/long");
|
|
cut_lj_global = utils::numeric(FLERR,*(arg++),false,lmp);
|
|
if (narg == 4 && ((ewald_order & 0x42) == 0x42))
|
|
error->all(FLERR,"Only one cutoff allowed when requesting all long");
|
|
if (narg == 4) cut_coul = utils::numeric(FLERR,*arg,false,lmp);
|
|
else cut_coul = cut_lj_global;
|
|
|
|
if (allocated) {
|
|
int i,j;
|
|
for (i = 1; i <= atom->ntypes; i++)
|
|
for (j = i; j <= atom->ntypes; j++)
|
|
if (setflag[i][j]) cut_lj[i][j] = cut_lj_global;
|
|
}
|
|
}
|
|
|
|
/* ----------------------------------------------------------------------
|
|
free all arrays
|
|
------------------------------------------------------------------------- */
|
|
|
|
PairLJLongCoulLong::~PairLJLongCoulLong()
|
|
{
|
|
if (allocated) {
|
|
memory->destroy(setflag);
|
|
memory->destroy(cutsq);
|
|
|
|
memory->destroy(cut_lj_read);
|
|
memory->destroy(cut_lj);
|
|
memory->destroy(cut_ljsq);
|
|
memory->destroy(epsilon_read);
|
|
memory->destroy(epsilon);
|
|
memory->destroy(sigma_read);
|
|
memory->destroy(sigma);
|
|
memory->destroy(lj1);
|
|
memory->destroy(lj2);
|
|
memory->destroy(lj3);
|
|
memory->destroy(lj4);
|
|
memory->destroy(offset);
|
|
}
|
|
if (ftable) free_tables();
|
|
if (fdisptable) free_disp_tables();
|
|
}
|
|
|
|
/* ----------------------------------------------------------------------
|
|
allocate all arrays
|
|
------------------------------------------------------------------------- */
|
|
|
|
void PairLJLongCoulLong::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_read,n+1,n+1,"pair:cut_lj_read");
|
|
memory->create(cut_lj,n+1,n+1,"pair:cut_lj");
|
|
memory->create(cut_ljsq,n+1,n+1,"pair:cut_ljsq");
|
|
memory->create(epsilon_read,n+1,n+1,"pair:epsilon_read");
|
|
memory->create(epsilon,n+1,n+1,"pair:epsilon");
|
|
memory->create(sigma_read,n+1,n+1,"pair:sigma_read");
|
|
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");
|
|
}
|
|
|
|
/* ----------------------------------------------------------------------
|
|
extract protected data from object
|
|
------------------------------------------------------------------------- */
|
|
|
|
void *PairLJLongCoulLong::extract(const char *id, int &dim)
|
|
{
|
|
const char *ids[] = {
|
|
"B", "sigma", "epsilon", "ewald_order", "ewald_cut", "ewald_mix",
|
|
"cut_coul", "cut_LJ", NULL};
|
|
void *ptrs[] = {
|
|
lj4, sigma, epsilon, &ewald_order, &cut_coul, &mix_flag,
|
|
&cut_coul, &cut_lj_global, NULL};
|
|
int i;
|
|
|
|
for (i=0; ids[i]&&strcmp(ids[i], id); ++i);
|
|
if (i <= 2) dim = 2;
|
|
else dim = 0;
|
|
return ptrs[i];
|
|
}
|
|
|
|
/* ----------------------------------------------------------------------
|
|
set coeffs for one or more type pairs
|
|
------------------------------------------------------------------------- */
|
|
|
|
void PairLJLongCoulLong::coeff(int narg, char **arg)
|
|
{
|
|
if (narg < 4 || narg > 5) error->all(FLERR,"Incorrect args for pair coefficients");
|
|
if (!allocated) allocate();
|
|
|
|
int ilo,ihi,jlo,jhi;
|
|
utils::bounds(FLERR,arg[0],1,atom->ntypes,ilo,ihi,error);
|
|
utils::bounds(FLERR,arg[1],1,atom->ntypes,jlo,jhi,error);
|
|
|
|
double epsilon_one = utils::numeric(FLERR,arg[2],false,lmp);
|
|
double sigma_one = utils::numeric(FLERR,arg[3],false,lmp);
|
|
|
|
double cut_lj_one = cut_lj_global;
|
|
if (narg == 5) cut_lj_one = utils::numeric(FLERR,arg[4],false,lmp);
|
|
|
|
int count = 0;
|
|
for (int i = ilo; i <= ihi; i++) {
|
|
for (int j = MAX(jlo,i); j <= jhi; j++) {
|
|
epsilon_read[i][j] = epsilon_one;
|
|
sigma_read[i][j] = sigma_one;
|
|
cut_lj_read[i][j] = cut_lj_one;
|
|
setflag[i][j] = 1;
|
|
count++;
|
|
}
|
|
}
|
|
|
|
if (count == 0) error->all(FLERR,"Incorrect args for pair coefficients");
|
|
}
|
|
|
|
/* ----------------------------------------------------------------------
|
|
init specific to this pair style
|
|
------------------------------------------------------------------------- */
|
|
|
|
void PairLJLongCoulLong::init_style()
|
|
{
|
|
// require an atom style with charge defined
|
|
|
|
if (!atom->q_flag && (ewald_order&(1<<1)))
|
|
error->all(FLERR,
|
|
"Invoking coulombic in pair style lj/long/coul/long requires atom attribute q");
|
|
|
|
// ensure use of KSpace long-range solver, set two g_ewalds
|
|
|
|
if (force->kspace == NULL)
|
|
error->all(FLERR,"Pair style requires a KSpace style");
|
|
if (ewald_order&(1<<1)) g_ewald = force->kspace->g_ewald;
|
|
if (ewald_order&(1<<6)) g_ewald_6 = force->kspace->g_ewald_6;
|
|
|
|
// 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;
|
|
|
|
// setup force tables
|
|
|
|
if (ncoultablebits && (ewald_order&(1<<1))) init_tables(cut_coul,cut_respa);
|
|
if (ndisptablebits && (ewald_order&(1<<6))) init_tables_disp(cut_lj_global);
|
|
|
|
// request regular or rRESPA neighbor lists if neighrequest_flag != 0
|
|
|
|
if (force->kspace->neighrequest_flag) {
|
|
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;
|
|
}
|
|
|
|
cut_coulsq = cut_coul * cut_coul;
|
|
}
|
|
|
|
/* ----------------------------------------------------------------------
|
|
init for one type pair i,j and corresponding j,i
|
|
------------------------------------------------------------------------- */
|
|
|
|
double PairLJLongCoulLong::init_one(int i, int j)
|
|
{
|
|
if (setflag[i][j] == 0) {
|
|
epsilon[i][j] = mix_energy(epsilon_read[i][i],epsilon_read[j][j],
|
|
sigma_read[i][i],sigma_read[j][j]);
|
|
sigma[i][j] = mix_distance(sigma_read[i][i],sigma_read[j][j]);
|
|
if (ewald_order&(1<<6))
|
|
cut_lj[i][j] = cut_lj_global;
|
|
else
|
|
cut_lj[i][j] = mix_distance(cut_lj_read[i][i],cut_lj_read[j][j]);
|
|
}
|
|
else {
|
|
sigma[i][j] = sigma_read[i][j];
|
|
epsilon[i][j] = epsilon_read[i][j];
|
|
cut_lj[i][j] = cut_lj_read[i][j];
|
|
}
|
|
|
|
double cut = MAX(cut_lj[i][j], cut_coul + 2.0*qdist);
|
|
cutsq[i][j] = cut*cut;
|
|
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);
|
|
|
|
// 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");
|
|
|
|
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;
|
|
|
|
cutsq[j][i] = cutsq[i][j];
|
|
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];
|
|
|
|
return cut;
|
|
}
|
|
|
|
/* ----------------------------------------------------------------------
|
|
proc 0 writes to restart file
|
|
------------------------------------------------------------------------- */
|
|
|
|
void PairLJLongCoulLong::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_read[i][j],sizeof(double),1,fp);
|
|
fwrite(&sigma_read[i][j],sizeof(double),1,fp);
|
|
fwrite(&cut_lj_read[i][j],sizeof(double),1,fp);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* ----------------------------------------------------------------------
|
|
proc 0 reads from restart file, bcasts
|
|
------------------------------------------------------------------------- */
|
|
|
|
void PairLJLongCoulLong::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) utils::sfread(FLERR,&setflag[i][j],sizeof(int),1,fp,NULL,error);
|
|
MPI_Bcast(&setflag[i][j],1,MPI_INT,0,world);
|
|
if (setflag[i][j]) {
|
|
if (me == 0) {
|
|
utils::sfread(FLERR,&epsilon_read[i][j],sizeof(double),1,fp,NULL,error);
|
|
utils::sfread(FLERR,&sigma_read[i][j],sizeof(double),1,fp,NULL,error);
|
|
utils::sfread(FLERR,&cut_lj_read[i][j],sizeof(double),1,fp,NULL,error);
|
|
}
|
|
MPI_Bcast(&epsilon_read[i][j],1,MPI_DOUBLE,0,world);
|
|
MPI_Bcast(&sigma_read[i][j],1,MPI_DOUBLE,0,world);
|
|
MPI_Bcast(&cut_lj_read[i][j],1,MPI_DOUBLE,0,world);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* ----------------------------------------------------------------------
|
|
proc 0 writes to restart file
|
|
------------------------------------------------------------------------- */
|
|
|
|
void PairLJLongCoulLong::write_restart_settings(FILE *fp)
|
|
{
|
|
fwrite(&cut_lj_global,sizeof(double),1,fp);
|
|
fwrite(&cut_coul,sizeof(double),1,fp);
|
|
fwrite(&offset_flag,sizeof(int),1,fp);
|
|
fwrite(&mix_flag,sizeof(int),1,fp);
|
|
fwrite(&ncoultablebits,sizeof(int),1,fp);
|
|
fwrite(&tabinner,sizeof(double),1,fp);
|
|
fwrite(&ewald_order,sizeof(int),1,fp);
|
|
fwrite(&dispersionflag,sizeof(int),1,fp);
|
|
}
|
|
|
|
/* ----------------------------------------------------------------------
|
|
proc 0 reads from restart file, bcasts
|
|
------------------------------------------------------------------------- */
|
|
|
|
void PairLJLongCoulLong::read_restart_settings(FILE *fp)
|
|
{
|
|
if (comm->me == 0) {
|
|
utils::sfread(FLERR,&cut_lj_global,sizeof(double),1,fp,NULL,error);
|
|
utils::sfread(FLERR,&cut_coul,sizeof(double),1,fp,NULL,error);
|
|
utils::sfread(FLERR,&offset_flag,sizeof(int),1,fp,NULL,error);
|
|
utils::sfread(FLERR,&mix_flag,sizeof(int),1,fp,NULL,error);
|
|
utils::sfread(FLERR,&ncoultablebits,sizeof(int),1,fp,NULL,error);
|
|
utils::sfread(FLERR,&tabinner,sizeof(double),1,fp,NULL,error);
|
|
utils::sfread(FLERR,&ewald_order,sizeof(int),1,fp,NULL,error);
|
|
utils::sfread(FLERR,&dispersionflag,sizeof(int),1,fp,NULL,error);
|
|
}
|
|
MPI_Bcast(&cut_lj_global,1,MPI_DOUBLE,0,world);
|
|
MPI_Bcast(&cut_coul,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(&ncoultablebits,1,MPI_INT,0,world);
|
|
MPI_Bcast(&tabinner,1,MPI_DOUBLE,0,world);
|
|
MPI_Bcast(&ewald_order,1,MPI_INT,0,world);
|
|
MPI_Bcast(&dispersionflag,1,MPI_INT,0,world);
|
|
}
|
|
|
|
/* ----------------------------------------------------------------------
|
|
proc 0 writes to data file
|
|
------------------------------------------------------------------------- */
|
|
|
|
void PairLJLongCoulLong::write_data(FILE *fp)
|
|
{
|
|
for (int i = 1; i <= atom->ntypes; i++)
|
|
fmt::print(fp,"{} {} {}\n",i,epsilon_read[i][i],sigma_read[i][i]);
|
|
}
|
|
|
|
/* ----------------------------------------------------------------------
|
|
proc 0 writes all pairs to data file. must use the "mixed" parameters.
|
|
also must not write out cutoff for lj = long
|
|
------------------------------------------------------------------------- */
|
|
|
|
void PairLJLongCoulLong::write_data_all(FILE *fp)
|
|
{
|
|
for (int i = 1; i <= atom->ntypes; i++) {
|
|
for (int j = i; j <= atom->ntypes; j++) {
|
|
if (ewald_order & (1<<6)) {
|
|
fmt::print(fp,"{} {} {} {}\n",i,j,
|
|
epsilon[i][j],sigma[i][j]);
|
|
} else {
|
|
fmt::print(fp,"{} {} {} {} {}\n",i,j,
|
|
epsilon[i][j],sigma[i][j],cut_lj[i][j]);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* ----------------------------------------------------------------------
|
|
compute pair interactions
|
|
------------------------------------------------------------------------- */
|
|
|
|
void PairLJLongCoulLong::compute(int eflag, int vflag)
|
|
{
|
|
double evdwl,ecoul,fpair;
|
|
evdwl = ecoul = 0.0;
|
|
ev_init(eflag,vflag);
|
|
|
|
double **x = atom->x, *x0 = x[0];
|
|
double **f = atom->f, *f0 = f[0], *fi = f0;
|
|
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 i, j, order1 = ewald_order&(1<<1), order6 = ewald_order&(1<<6);
|
|
int *ineigh, *ineighn, *jneigh, *jneighn, typei, typej, ni;
|
|
double qi = 0.0, qri = 0.0;
|
|
double *cutsqi, *cut_ljsqi, *lj1i, *lj2i, *lj3i, *lj4i, *offseti;
|
|
double rsq, r2inv, force_coul, force_lj;
|
|
double g2 = g_ewald_6*g_ewald_6, g6 = g2*g2*g2, g8 = g6*g2;
|
|
vector xi, d;
|
|
|
|
ineighn = (ineigh = list->ilist)+list->inum;
|
|
|
|
for (; ineigh<ineighn; ++ineigh) { // loop over my atoms
|
|
i = *ineigh; fi = f0+3*i;
|
|
if (order1) qri = (qi = q[i])*qqrd2e; // initialize constants
|
|
offseti = offset[typei = type[i]];
|
|
lj1i = lj1[typei]; lj2i = lj2[typei]; lj3i = lj3[typei]; lj4i = lj4[typei];
|
|
cutsqi = cutsq[typei]; cut_ljsqi = cut_ljsq[typei];
|
|
memcpy(xi, x0+(i+(i<<1)), sizeof(vector));
|
|
jneighn = (jneigh = list->firstneigh[i])+list->numneigh[i];
|
|
|
|
for (; jneigh<jneighn; ++jneigh) { // loop over neighbors
|
|
j = *jneigh;
|
|
ni = sbmask(j);
|
|
j &= NEIGHMASK;
|
|
|
|
{ double *xj = x0+(j+(j<<1));
|
|
d[0] = xi[0] - xj[0]; // pair vector
|
|
d[1] = xi[1] - xj[1];
|
|
d[2] = xi[2] - xj[2]; }
|
|
|
|
if ((rsq = vec_dot(d, d)) >= cutsqi[typej = type[j]]) continue;
|
|
r2inv = 1.0/rsq;
|
|
|
|
if (order1 && (rsq < cut_coulsq)) { // coulombic
|
|
if (!ncoultablebits || rsq <= tabinnersq) { // series real space
|
|
double r = sqrt(rsq), x = g_ewald*r;
|
|
double s = qri*q[j], t = 1.0/(1.0+EWALD_P*x);
|
|
if (ni == 0) {
|
|
s *= g_ewald*exp(-x*x);
|
|
force_coul = (t *= ((((t*A5+A4)*t+A3)*t+A2)*t+A1)*s/x)+EWALD_F*s;
|
|
if (eflag) ecoul = t;
|
|
} else { // special case
|
|
r = s*(1.0-special_coul[ni])/r; s *= g_ewald*exp(-x*x);
|
|
force_coul = (t *= ((((t*A5+A4)*t+A3)*t+A2)*t+A1)*s/x)+EWALD_F*s-r;
|
|
if (eflag) ecoul = t-r;
|
|
}
|
|
} else { // table real space
|
|
union_int_float_t t;
|
|
t.f = rsq;
|
|
const int k = (t.i & ncoulmask)>>ncoulshiftbits;
|
|
double f = (rsq-rtable[k])*drtable[k], qiqj = qi*q[j];
|
|
if (ni == 0) {
|
|
force_coul = qiqj*(ftable[k]+f*dftable[k]);
|
|
if (eflag) ecoul = qiqj*(etable[k]+f*detable[k]);
|
|
} else { // special case
|
|
t.f = (1.0-special_coul[ni])*(ctable[k]+f*dctable[k]);
|
|
force_coul = qiqj*(ftable[k]+f*dftable[k]-t.f);
|
|
if (eflag) ecoul = qiqj*(etable[k]+f*detable[k]-t.f);
|
|
}
|
|
}
|
|
} else force_coul = ecoul = 0.0;
|
|
|
|
if (rsq < cut_ljsqi[typej]) { // lj
|
|
if (order6) { // long-range lj
|
|
if(!ndisptablebits || rsq <= tabinnerdispsq) { // series real space
|
|
double rn = r2inv*r2inv*r2inv;
|
|
double x2 = g2*rsq, a2 = 1.0/x2;
|
|
x2 = a2*exp(-x2)*lj4i[typej];
|
|
if (ni == 0) {
|
|
force_lj =
|
|
(rn*=rn)*lj1i[typej]-g8*(((6.0*a2+6.0)*a2+3.0)*a2+1.0)*x2*rsq;
|
|
if (eflag)
|
|
evdwl = rn*lj3i[typej]-g6*((a2+1.0)*a2+0.5)*x2;
|
|
} else { // special case
|
|
double f = special_lj[ni], t = rn*(1.0-f);
|
|
force_lj = f*(rn *= rn)*lj1i[typej]-
|
|
g8*(((6.0*a2+6.0)*a2+3.0)*a2+1.0)*x2*rsq+t*lj2i[typej];
|
|
if (eflag)
|
|
evdwl = f*rn*lj3i[typej]-g6*((a2+1.0)*a2+0.5)*x2+t*lj4i[typej];
|
|
}
|
|
} else { // table real space
|
|
union_int_float_t disp_t;
|
|
disp_t.f = rsq;
|
|
const int disp_k = (disp_t.i & ndispmask)>>ndispshiftbits;
|
|
double f_disp = (rsq-rdisptable[disp_k])*drdisptable[disp_k];
|
|
double rn = r2inv*r2inv*r2inv;
|
|
if (ni == 0) {
|
|
force_lj = (rn*=rn)*lj1i[typej]-(fdisptable[disp_k]+f_disp*dfdisptable[disp_k])*lj4i[typej];
|
|
if (eflag) evdwl = rn*lj3i[typej]-(edisptable[disp_k]+f_disp*dedisptable[disp_k])*lj4i[typej];
|
|
} else { // special case
|
|
double f = special_lj[ni], t = rn*(1.0-f);
|
|
force_lj = f*(rn *= rn)*lj1i[typej]-(fdisptable[disp_k]+f_disp*dfdisptable[disp_k])*lj4i[typej]+t*lj2i[typej];
|
|
if (eflag) evdwl = f*rn*lj3i[typej]-(edisptable[disp_k]+f_disp*dedisptable[disp_k])*lj4i[typej]+t*lj4i[typej];
|
|
}
|
|
}
|
|
}
|
|
else { // cut lj
|
|
double rn = r2inv*r2inv*r2inv;
|
|
if (ni == 0) {
|
|
force_lj = rn*(rn*lj1i[typej]-lj2i[typej]);
|
|
if (eflag) evdwl = rn*(rn*lj3i[typej]-lj4i[typej])-offseti[typej];
|
|
}
|
|
else { // special case
|
|
double f = special_lj[ni];
|
|
force_lj = f*rn*(rn*lj1i[typej]-lj2i[typej]);
|
|
if (eflag)
|
|
evdwl = f * (rn*(rn*lj3i[typej]-lj4i[typej])-offseti[typej]);
|
|
}
|
|
}
|
|
}
|
|
|
|
else force_lj = evdwl = 0.0;
|
|
|
|
fpair = (force_coul+force_lj)*r2inv;
|
|
|
|
if (newton_pair || j < nlocal) {
|
|
double *fj = f0+(j+(j<<1)), f;
|
|
fi[0] += f = d[0]*fpair; fj[0] -= f;
|
|
fi[1] += f = d[1]*fpair; fj[1] -= f;
|
|
fi[2] += f = d[2]*fpair; fj[2] -= f;
|
|
}
|
|
else {
|
|
fi[0] += d[0]*fpair;
|
|
fi[1] += d[1]*fpair;
|
|
fi[2] += d[2]*fpair;
|
|
}
|
|
|
|
if (evflag) ev_tally(i,j,nlocal,newton_pair,
|
|
evdwl,ecoul,fpair,d[0],d[1],d[2]);
|
|
}
|
|
}
|
|
|
|
if (vflag_fdotr) virial_fdotr_compute();
|
|
}
|
|
|
|
/* ---------------------------------------------------------------------- */
|
|
|
|
void PairLJLongCoulLong::compute_inner()
|
|
{
|
|
double rsq, r2inv, force_coul = 0.0, force_lj, fpair;
|
|
|
|
int *type = atom->type;
|
|
int nlocal = atom->nlocal;
|
|
double *x0 = atom->x[0], *f0 = atom->f[0], *fi = f0, *q = atom->q;
|
|
double *special_coul = force->special_coul;
|
|
double *special_lj = force->special_lj;
|
|
int newton_pair = force->newton_pair;
|
|
double qqrd2e = force->qqrd2e;
|
|
|
|
|
|
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;
|
|
|
|
int *ineigh, *ineighn, *jneigh, *jneighn, typei, typej, ni;
|
|
int i, j, order1 = (ewald_order|(ewald_off^-1))&(1<<1);
|
|
double qri, *cut_ljsqi, *lj1i, *lj2i;
|
|
vector xi, d;
|
|
|
|
ineighn = (ineigh = list->ilist_inner)+list->inum_inner;
|
|
for (; ineigh<ineighn; ++ineigh) { // loop over my atoms
|
|
i = *ineigh; fi = f0+3*i;
|
|
memcpy(xi, x0+(i+(i<<1)), sizeof(vector));
|
|
cut_ljsqi = cut_ljsq[typei = type[i]];
|
|
lj1i = lj1[typei]; lj2i = lj2[typei];
|
|
jneighn = (jneigh = list->firstneigh_inner[i])+list->numneigh_inner[i];
|
|
for (; jneigh<jneighn; ++jneigh) { // loop over neighbors
|
|
j = *jneigh;
|
|
ni = sbmask(j);
|
|
j &= NEIGHMASK;
|
|
|
|
{ double *xj = x0+(j+(j<<1));
|
|
d[0] = xi[0] - xj[0]; // pair vector
|
|
d[1] = xi[1] - xj[1];
|
|
d[2] = xi[2] - xj[2]; }
|
|
|
|
if ((rsq = vec_dot(d, d)) >= cut_out_off_sq) continue;
|
|
r2inv = 1.0/rsq;
|
|
|
|
if (order1 && (rsq < cut_coulsq)) { // coulombic
|
|
qri = qqrd2e*q[i];
|
|
force_coul = ni == 0 ?
|
|
qri*q[j]*sqrt(r2inv) : qri*q[j]*sqrt(r2inv)*special_coul[ni];
|
|
}
|
|
|
|
if (rsq < cut_ljsqi[typej = type[j]]) { // lennard-jones
|
|
double rn = r2inv*r2inv*r2inv;
|
|
force_lj = ni == 0 ?
|
|
rn*(rn*lj1i[typej]-lj2i[typej]) :
|
|
rn*(rn*lj1i[typej]-lj2i[typej])*special_lj[ni];
|
|
}
|
|
else force_lj = 0.0;
|
|
|
|
fpair = (force_coul + force_lj) * r2inv;
|
|
|
|
if (rsq > cut_out_on_sq) { // switching
|
|
double rsw = (sqrt(rsq) - cut_out_on)/cut_out_diff;
|
|
fpair *= 1.0 + rsw*rsw*(2.0*rsw-3.0);
|
|
}
|
|
|
|
if (newton_pair || j < nlocal) { // force update
|
|
double *fj = f0+(j+(j<<1)), f;
|
|
fi[0] += f = d[0]*fpair; fj[0] -= f;
|
|
fi[1] += f = d[1]*fpair; fj[1] -= f;
|
|
fi[2] += f = d[2]*fpair; fj[2] -= f;
|
|
}
|
|
else {
|
|
fi[0] += d[0]*fpair;
|
|
fi[1] += d[1]*fpair;
|
|
fi[2] += d[2]*fpair;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* ---------------------------------------------------------------------- */
|
|
|
|
void PairLJLongCoulLong::compute_middle()
|
|
{
|
|
double rsq, r2inv, force_coul = 0.0, force_lj, fpair;
|
|
|
|
int *type = atom->type;
|
|
int nlocal = atom->nlocal;
|
|
double *x0 = atom->x[0], *f0 = atom->f[0], *fi = f0, *q = atom->q;
|
|
double *special_coul = force->special_coul;
|
|
double *special_lj = force->special_lj;
|
|
int newton_pair = force->newton_pair;
|
|
double qqrd2e = force->qqrd2e;
|
|
|
|
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;
|
|
|
|
int *ineigh, *ineighn, *jneigh, *jneighn, typei, typej, ni;
|
|
int i, j, order1 = (ewald_order|(ewald_off^-1))&(1<<1);
|
|
double qri, *cut_ljsqi, *lj1i, *lj2i;
|
|
vector xi, d;
|
|
|
|
ineighn = (ineigh = list->ilist_middle)+list->inum_middle;
|
|
|
|
for (; ineigh<ineighn; ++ineigh) { // loop over my atoms
|
|
i = *ineigh; fi = f0+3*i;
|
|
if (order1) qri = qqrd2e*q[i];
|
|
memcpy(xi, x0+(i+(i<<1)), sizeof(vector));
|
|
cut_ljsqi = cut_ljsq[typei = type[i]];
|
|
lj1i = lj1[typei]; lj2i = lj2[typei];
|
|
jneighn = (jneigh = list->firstneigh_middle[i])+list->numneigh_middle[i];
|
|
|
|
for (; jneigh<jneighn; ++jneigh) {
|
|
j = *jneigh;
|
|
ni = sbmask(j);
|
|
j &= NEIGHMASK;
|
|
|
|
{ double *xj = x0+(j+(j<<1));
|
|
d[0] = xi[0] - xj[0]; // pair vector
|
|
d[1] = xi[1] - xj[1];
|
|
d[2] = xi[2] - xj[2]; }
|
|
|
|
if ((rsq = vec_dot(d, d)) >= cut_out_off_sq) continue;
|
|
if (rsq <= cut_in_off_sq) continue;
|
|
r2inv = 1.0/rsq;
|
|
|
|
if (order1 && (rsq < cut_coulsq)) // coulombic
|
|
force_coul = ni == 0 ?
|
|
qri*q[j]*sqrt(r2inv) : qri*q[j]*sqrt(r2inv)*special_coul[ni];
|
|
|
|
if (rsq < cut_ljsqi[typej = type[j]]) { // lennard-jones
|
|
double rn = r2inv*r2inv*r2inv;
|
|
force_lj = ni == 0 ?
|
|
rn*(rn*lj1i[typej]-lj2i[typej]) :
|
|
rn*(rn*lj1i[typej]-lj2i[typej])*special_lj[ni];
|
|
}
|
|
else force_lj = 0.0;
|
|
|
|
fpair = (force_coul + force_lj) * r2inv;
|
|
|
|
if (rsq < cut_in_on_sq) { // switching
|
|
double rsw = (sqrt(rsq) - cut_in_off)/cut_in_diff;
|
|
fpair *= rsw*rsw*(3.0 - 2.0*rsw);
|
|
}
|
|
if (rsq > cut_out_on_sq) {
|
|
double rsw = (sqrt(rsq) - cut_out_on)/cut_out_diff;
|
|
fpair *= 1.0 + rsw*rsw*(2.0*rsw-3.0);
|
|
}
|
|
|
|
if (newton_pair || j < nlocal) { // force update
|
|
double *fj = f0+(j+(j<<1)), f;
|
|
fi[0] += f = d[0]*fpair; fj[0] -= f;
|
|
fi[1] += f = d[1]*fpair; fj[1] -= f;
|
|
fi[2] += f = d[2]*fpair; fj[2] -= f;
|
|
}
|
|
else {
|
|
fi[0] += d[0]*fpair;
|
|
fi[1] += d[1]*fpair;
|
|
fi[2] += d[2]*fpair;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* ---------------------------------------------------------------------- */
|
|
|
|
void PairLJLongCoulLong::compute_outer(int eflag, int vflag)
|
|
{
|
|
double evdwl,ecoul,fvirial,fpair;
|
|
evdwl = ecoul = 0.0;
|
|
ev_init(eflag,vflag);
|
|
|
|
double **x = atom->x, *x0 = x[0];
|
|
double **f = atom->f, *f0 = f[0], *fi = f0;
|
|
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 i, j, order1 = ewald_order&(1<<1), order6 = ewald_order&(1<<6);
|
|
int *ineigh, *ineighn, *jneigh, *jneighn, typei, typej, ni, respa_flag;
|
|
double qi = 0.0, qri = 0.0;
|
|
double *cutsqi, *cut_ljsqi, *lj1i, *lj2i, *lj3i, *lj4i, *offseti;
|
|
double rsq, r2inv, force_coul, force_lj;
|
|
double g2 = g_ewald_6*g_ewald_6, g6 = g2*g2*g2, g8 = g6*g2;
|
|
double respa_lj = 0.0, respa_coul = 0.0, frespa = 0.0;
|
|
vector xi, d;
|
|
|
|
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;
|
|
|
|
ineighn = (ineigh = list->ilist)+list->inum;
|
|
|
|
for (; ineigh<ineighn; ++ineigh) { // loop over my atoms
|
|
i = *ineigh; fi = f0+3*i;
|
|
if (order1) qri = (qi = q[i])*qqrd2e; // initialize constants
|
|
offseti = offset[typei = type[i]];
|
|
lj1i = lj1[typei]; lj2i = lj2[typei]; lj3i = lj3[typei]; lj4i = lj4[typei];
|
|
cutsqi = cutsq[typei]; cut_ljsqi = cut_ljsq[typei];
|
|
memcpy(xi, x0+(i+(i<<1)), sizeof(vector));
|
|
jneighn = (jneigh = list->firstneigh[i])+list->numneigh[i];
|
|
|
|
for (; jneigh<jneighn; ++jneigh) { // loop over neighbors
|
|
j = *jneigh;
|
|
ni = sbmask(j);
|
|
j &= NEIGHMASK;
|
|
|
|
{ double *xj = x0+(j+(j<<1));
|
|
d[0] = xi[0] - xj[0]; // pair vector
|
|
d[1] = xi[1] - xj[1];
|
|
d[2] = xi[2] - xj[2]; }
|
|
|
|
if ((rsq = vec_dot(d, d)) >= cutsqi[typej = type[j]]) continue;
|
|
r2inv = 1.0/rsq;
|
|
|
|
frespa = 1.0; // check whether and how to compute respa corrections
|
|
respa_coul = 0;
|
|
respa_lj = 0;
|
|
respa_flag = rsq < cut_in_on_sq ? 1 : 0;
|
|
if (respa_flag && (rsq > cut_in_off_sq)) {
|
|
double rsw = (sqrt(rsq)-cut_in_off)/cut_in_diff;
|
|
frespa = 1-rsw*rsw*(3.0-2.0*rsw);
|
|
}
|
|
|
|
if (order1 && (rsq < cut_coulsq)) { // coulombic
|
|
if (!ncoultablebits || rsq <= tabinnersq) { // series real space
|
|
double r = sqrt(rsq), s = qri*q[j];
|
|
if (respa_flag) // correct for respa
|
|
respa_coul = ni == 0 ? frespa*s/r : frespa*s/r*special_coul[ni];
|
|
double x = g_ewald*r, t = 1.0/(1.0+EWALD_P*x);
|
|
if (ni == 0) {
|
|
s *= g_ewald*exp(-x*x);
|
|
force_coul = (t *= ((((t*A5+A4)*t+A3)*t+A2)*t+A1)*s/x)+EWALD_F*s-respa_coul;
|
|
if (eflag) ecoul = t;
|
|
}
|
|
else { // correct for special
|
|
r = s*(1.0-special_coul[ni])/r; s *= g_ewald*exp(-x*x);
|
|
force_coul = (t *= ((((t*A5+A4)*t+A3)*t+A2)*t+A1)*s/x)+EWALD_F*s-r-respa_coul;
|
|
if (eflag) ecoul = t-r;
|
|
}
|
|
} // table real space
|
|
else {
|
|
if (respa_flag) {
|
|
double r = sqrt(rsq), s = qri*q[j];
|
|
respa_coul = ni == 0 ? frespa*s/r : frespa*s/r*special_coul[ni];
|
|
}
|
|
union_int_float_t t;
|
|
t.f = rsq;
|
|
const int k = (t.i & ncoulmask) >> ncoulshiftbits;
|
|
double f = (rsq-rtable[k])*drtable[k], qiqj = qi*q[j];
|
|
if (ni == 0) {
|
|
force_coul = qiqj*(ftable[k]+f*dftable[k]);
|
|
if (eflag) ecoul = qiqj*(etable[k]+f*detable[k]);
|
|
}
|
|
else { // correct for special
|
|
t.f = (1.0-special_coul[ni])*(ctable[k]+f*dctable[k]);
|
|
force_coul = qiqj*(ftable[k]+f*dftable[k]-t.f);
|
|
if (eflag) {
|
|
t.f = (1.0-special_coul[ni])*(ptable[k]+f*dptable[k]);
|
|
ecoul = qiqj*(etable[k]+f*detable[k]-t.f);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
else force_coul = respa_coul = ecoul = 0.0;
|
|
|
|
if (rsq < cut_ljsqi[typej]) { // lennard-jones
|
|
double rn = r2inv*r2inv*r2inv;
|
|
if (respa_flag) respa_lj = ni == 0 ? // correct for respa
|
|
frespa*rn*(rn*lj1i[typej]-lj2i[typej]) :
|
|
frespa*rn*(rn*lj1i[typej]-lj2i[typej])*special_lj[ni];
|
|
if (order6) { // long-range form
|
|
if (!ndisptablebits || rsq <= tabinnerdispsq) {
|
|
double x2 = g2*rsq, a2 = 1.0/x2;
|
|
x2 = a2*exp(-x2)*lj4i[typej];
|
|
if (ni == 0) {
|
|
force_lj =
|
|
(rn*=rn)*lj1i[typej]-g8*(((6.0*a2+6.0)*a2+3.0)*a2+1.0)*x2*rsq-respa_lj;
|
|
if (eflag) evdwl = rn*lj3i[typej]-g6*((a2+1.0)*a2+0.5)*x2;
|
|
}
|
|
else { // correct for special
|
|
double f = special_lj[ni], t = rn*(1.0-f);
|
|
force_lj = f*(rn *= rn)*lj1i[typej]-
|
|
g8*(((6.0*a2+6.0)*a2+3.0)*a2+1.0)*x2*rsq+t*lj2i[typej]-respa_lj;
|
|
if (eflag)
|
|
evdwl = f*rn*lj3i[typej]-g6*((a2+1.0)*a2+0.5)*x2+t*lj4i[typej];
|
|
}
|
|
}
|
|
else { // table real space
|
|
union_int_float_t disp_t;
|
|
disp_t.f = rsq;
|
|
const int disp_k = (disp_t.i & ndispmask)>>ndispshiftbits;
|
|
double f_disp = (rsq-rdisptable[disp_k])*drdisptable[disp_k];
|
|
double rn = r2inv*r2inv*r2inv;
|
|
if (ni == 0) {
|
|
force_lj = (rn*=rn)*lj1i[typej]-(fdisptable[disp_k]+f_disp*dfdisptable[disp_k])*lj4i[typej]-respa_lj;
|
|
if (eflag) evdwl = rn*lj3i[typej]-(edisptable[disp_k]+f_disp*dedisptable[disp_k])*lj4i[typej];
|
|
}
|
|
else { // special case
|
|
double f = special_lj[ni], t = rn*(1.0-f);
|
|
force_lj = f*(rn *= rn)*lj1i[typej]-(fdisptable[disp_k]+f_disp*dfdisptable[disp_k])*lj4i[typej]+t*lj2i[typej]-respa_lj;
|
|
if (eflag) evdwl = f*rn*lj3i[typej]-(edisptable[disp_k]+f_disp*dedisptable[disp_k])*lj4i[typej]+t*lj4i[typej];
|
|
}
|
|
}
|
|
}
|
|
else { // cut form
|
|
if (ni == 0) {
|
|
force_lj = rn*(rn*lj1i[typej]-lj2i[typej])-respa_lj;
|
|
if (eflag) evdwl = rn*(rn*lj3i[typej]-lj4i[typej])-offseti[typej];
|
|
}
|
|
else { // correct for special
|
|
double f = special_lj[ni];
|
|
force_lj = f*rn*(rn*lj1i[typej]-lj2i[typej])-respa_lj;
|
|
if (eflag)
|
|
evdwl = f*(rn*(rn*lj3i[typej]-lj4i[typej])-offseti[typej]);
|
|
}
|
|
}
|
|
}
|
|
else force_lj = respa_lj = evdwl = 0.0;
|
|
|
|
fpair = (force_coul+force_lj)*r2inv;
|
|
|
|
if (newton_pair || j < nlocal) {
|
|
double *fj = f0+(j+(j<<1)), f;
|
|
fi[0] += f = d[0]*fpair; fj[0] -= f;
|
|
fi[1] += f = d[1]*fpair; fj[1] -= f;
|
|
fi[2] += f = d[2]*fpair; fj[2] -= f;
|
|
}
|
|
else {
|
|
fi[0] += d[0]*fpair;
|
|
fi[1] += d[1]*fpair;
|
|
fi[2] += d[2]*fpair;
|
|
}
|
|
|
|
if (evflag) {
|
|
fvirial = (force_coul + force_lj + respa_coul + respa_lj)*r2inv;
|
|
ev_tally(i,j,nlocal,newton_pair,
|
|
evdwl,ecoul,fvirial,d[0],d[1],d[2]);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* ---------------------------------------------------------------------- */
|
|
|
|
double PairLJLongCoulLong::single(int i, int j, int itype, int jtype,
|
|
double rsq, double factor_coul, double factor_lj,
|
|
double &fforce)
|
|
{
|
|
double r2inv, r6inv, force_coul, force_lj;
|
|
double g2 = g_ewald_6*g_ewald_6, g6 = g2*g2*g2, g8 = g6*g2, *q = atom->q;
|
|
|
|
double eng = 0.0;
|
|
|
|
r2inv = 1.0/rsq;
|
|
if ((ewald_order&2) && (rsq < cut_coulsq)) { // coulombic
|
|
if (!ncoultablebits || rsq <= tabinnersq) { // series real space
|
|
double r = sqrt(rsq), x = g_ewald*r;
|
|
double s = force->qqrd2e*q[i]*q[j], t = 1.0/(1.0+EWALD_P*x);
|
|
r = s*(1.0-factor_coul)/r; s *= g_ewald*exp(-x*x);
|
|
force_coul = (t *= ((((t*A5+A4)*t+A3)*t+A2)*t+A1)*s/x)+EWALD_F*s-r;
|
|
eng += t-r;
|
|
} else { // table real space
|
|
union_int_float_t t;
|
|
t.f = rsq;
|
|
const int k = (t.i & ncoulmask) >> ncoulshiftbits;
|
|
double f = (rsq-rtable[k])*drtable[k], qiqj = q[i]*q[j];
|
|
t.f = (1.0-factor_coul)*(ctable[k]+f*dctable[k]);
|
|
force_coul = qiqj*(ftable[k]+f*dftable[k]-t.f);
|
|
eng += qiqj*(etable[k]+f*detable[k]-t.f);
|
|
}
|
|
} else force_coul = 0.0;
|
|
|
|
if (rsq < cut_ljsq[itype][jtype]) { // lennard-jones
|
|
r6inv = r2inv*r2inv*r2inv;
|
|
if (ewald_order&64) { // long-range
|
|
double x2 = g2*rsq, a2 = 1.0/x2, t = r6inv*(1.0-factor_lj);
|
|
x2 = a2*exp(-x2)*lj4[itype][jtype];
|
|
force_lj = factor_lj*(r6inv *= r6inv)*lj1[itype][jtype]-
|
|
g8*(((6.0*a2+6.0)*a2+3.0)*a2+1.0)*x2*rsq+t*lj2[itype][jtype];
|
|
eng += factor_lj*r6inv*lj3[itype][jtype]-
|
|
g6*((a2+1.0)*a2+0.5)*x2+t*lj4[itype][jtype];
|
|
} else { // cut
|
|
force_lj = factor_lj*r6inv*(lj1[itype][jtype]*r6inv-lj2[itype][jtype]);
|
|
eng += factor_lj*(r6inv*(r6inv*lj3[itype][jtype]-
|
|
lj4[itype][jtype])-offset[itype][jtype]);
|
|
}
|
|
} else force_lj = 0.0;
|
|
|
|
fforce = (force_coul+force_lj)*r2inv;
|
|
return eng;
|
|
}
|