842 lines
22 KiB
C++
842 lines
22 KiB
C++
/* ----------------------------------------------------------------------
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LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
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http://lammps.sandia.gov, Sandia National Laboratories
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Steve Plimpton, sjplimp@sandia.gov
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Copyright (2003) Sandia Corporation. Under the terms of Contract
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DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
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certain rights in this software. This software is distributed under
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the GNU General Public License.
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See the README file in the top-level LAMMPS directory.
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------------------------------------------------------------------------- */
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/* ----------------------------------------------------------------------
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Contributing author: Ray Shan (Sandia)
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------------------------------------------------------------------------- */
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#include "pair_coul_streitz.h"
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#include <mpi.h>
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#include <cmath>
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#include <cstdlib>
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#include <cstring>
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#include "atom.h"
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#include "comm.h"
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#include "force.h"
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#include "kspace.h"
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#include "neighbor.h"
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#include "neigh_list.h"
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#include "neigh_request.h"
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#include "math_const.h"
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#include "memory.h"
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#include "error.h"
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using namespace LAMMPS_NS;
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using namespace MathConst;
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#define MAXLINE 1024
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#define DELTA 4
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#define PGDELTA 1
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#define MAXNEIGH 24
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/* ---------------------------------------------------------------------- */
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PairCoulStreitz::PairCoulStreitz(LAMMPS *lmp) : Pair(lmp)
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{
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single_enable = 0;
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restartinfo = 0;
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one_coeff = 1;
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nmax = 0;
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nelements = 0;
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elements = NULL;
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nparams = 0;
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maxparam = 0;
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params = NULL;
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elem2param = NULL;
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}
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/* ----------------------------------------------------------------------
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check if allocated, since class can be destructed when incomplete
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------------------------------------------------------------------------- */
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PairCoulStreitz::~PairCoulStreitz()
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{
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if (elements)
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for (int i = 0; i < nelements; i++) delete [] elements[i];
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delete [] elements;
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memory->sfree(params);
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memory->destroy(elem2param);
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if (allocated) {
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memory->destroy(setflag);
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memory->destroy(cutsq);
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memory->destroy(scale);
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memory->destroy(qeq_x);
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memory->destroy(qeq_j);
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memory->destroy(qeq_g);
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memory->destroy(qeq_z);
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memory->destroy(qeq_c);
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delete [] map;
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}
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}
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/* ---------------------------------------------------------------------- */
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void PairCoulStreitz::allocate()
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{
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allocated = 1;
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int n = atom->ntypes;
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memory->create(setflag,n+1,n+1,"pair:setflag");
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memory->create(cutsq,n+1,n+1,"pair:cutsq");
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memory->create(scale,n+1,n+1,"pair:scale");
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memory->create(qeq_x,n+1,"pair:qeq_x");
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memory->create(qeq_j,n+1,"pair:qeq_j");
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memory->create(qeq_g,n+1,"pair:qeq_g");
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memory->create(qeq_z,n+1,"pair:qeq_z");
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memory->create(qeq_c,n+1,"pair:qeq_c");
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map = new int[n+1];
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}
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/* ----------------------------------------------------------------------
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global settings
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------------------------------------------------------------------------- */
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void PairCoulStreitz::settings(int narg, char **arg)
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{
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if (narg < 2) error->all(FLERR,"Illegal pair_style command");
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cut_coul = force->numeric(FLERR,arg[0]);
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if (strcmp(arg[1],"wolf") == 0){
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kspacetype = 1;
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g_wolf = force->numeric(FLERR,arg[2]);
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} else if (strcmp(arg[1],"ewald") == 0){
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ewaldflag = pppmflag = 1;
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kspacetype = 2;
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} else {
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error->all(FLERR,"Illegal pair_style command");
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}
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}
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/* ----------------------------------------------------------------------
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set coeffs for one or more type pairs
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------------------------------------------------------------------------- */
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void PairCoulStreitz::coeff(int narg, char **arg)
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{
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int i,j,n;
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if (!allocated) allocate();
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if (narg != 3 + atom->ntypes)
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error->all(FLERR,"Incorrect args for pair coefficients");
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// insure I,J args are * *
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if (strcmp(arg[0],"*") != 0 || strcmp(arg[1],"*") != 0)
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error->all(FLERR,"Incorrect args for pair coefficients");
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// read args that map atom types to elements in potential file
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// map[i] = which element the Ith atom type is, -1 if NULL
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// nelements = # of unique elements
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// elements = list of element names
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if (elements) {
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for (i = 0; i < nelements; i++) delete [] elements[i];
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delete [] elements;
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}
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elements = new char*[atom->ntypes];
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for (i = 0; i < atom->ntypes; i++) elements[i] = NULL;
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nelements = 0;
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for (i = 3; i < narg; i++) {
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if (strcmp(arg[i],"NULL") == 0) {
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map[i-2] = -1;
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continue;
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}
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for (j = 0; j < nelements; j++)
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if (strcmp(arg[i],elements[j]) == 0) break;
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map[i-2] = j;
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if (j == nelements) {
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n = strlen(arg[i]) + 1;
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elements[j] = new char[n];
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strcpy(elements[j],arg[i]);
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nelements++;
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}
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}
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// read potential file and initialize potential parameters
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read_file(arg[2]);
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setup_params();
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n = atom->ntypes;
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// clear setflag since coeff() called once with I,J = * *
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for (int i = 1; i <= n; i++)
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for (int j = i; j <= n; j++)
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setflag[i][j] = 0;
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// set setflag i,j for type pairs where both are mapped to elements
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int count = 0;
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for (int i = 1; i <= n; i++)
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for (int j = i; j <= n; j++)
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if (map[i] >= 0 && map[j] >= 0) {
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scale[i][j] = 1.0;
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setflag[i][j] = 1;
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count++;
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}
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if (count == 0) error->all(FLERR,"Incorrect args for pair coefficients");
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}
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/* ----------------------------------------------------------------------
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init specific to this pair style
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------------------------------------------------------------------------- */
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void PairCoulStreitz::init_style()
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{
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if (!atom->q_flag)
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error->all(FLERR,"Pair style coul/streitz requires atom attribute q");
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int irequest = neighbor->request(this,instance_me);
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neighbor->requests[irequest]->half = 0;
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neighbor->requests[irequest]->full = 1;
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cut_coulsq = cut_coul * cut_coul;
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// insure use of KSpace long-range solver when ewald specified, set g_ewald
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if (ewaldflag) {
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if (force->kspace == NULL)
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error->all(FLERR,"Pair style requires a KSpace style");
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g_ewald = force->kspace->g_ewald;
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}
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}
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/* ----------------------------------------------------------------------
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init for one type pair i,j and corresponding j,i
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------------------------------------------------------------------------- */
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double PairCoulStreitz::init_one(int i, int j)
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{
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scale[j][i] = scale[i][j];
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if (setflag[i][j] == 0) error->all(FLERR,"All pair coeffs are not set");
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return cut_coul;
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}
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/* ---------------------------------------------------------------------- */
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void PairCoulStreitz::read_file(char *file)
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{
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int params_per_line = 6;
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char **words = new char*[params_per_line+1];
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memory->sfree(params);
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params = NULL;
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nparams = 0;
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maxparam = 0;
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// open file on proc 0
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FILE *fp;
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if (comm->me == 0) {
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fp = fopen(file,"r");
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if (fp == NULL) {
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char str[128];
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snprintf(str,128,"Cannot open coul/streitz potential file %s",file);
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error->one(FLERR,str);
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}
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}
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// read each line out of file, skipping blank lines or leading '#'
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// store line of params if all 3 element tags are in element list
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int n,nwords,ielement;
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char line[MAXLINE],*ptr;
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int eof = 0;
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while (1) {
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if (comm->me == 0) {
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ptr = fgets(line,MAXLINE,fp);
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if (ptr == NULL) {
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eof = 1;
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fclose(fp);
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} else n = strlen(line) + 1;
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}
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MPI_Bcast(&eof,1,MPI_INT,0,world);
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if (eof) break;
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MPI_Bcast(&n,1,MPI_INT,0,world);
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MPI_Bcast(line,n,MPI_CHAR,0,world);
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// strip comment, skip line if blank
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if ((ptr = strchr(line,'#'))) *ptr = '\0';
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nwords = atom->count_words(line);
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if (nwords == 0) continue;
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// concatenate additional lines until have params_per_line words
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while (nwords < params_per_line) {
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n = strlen(line);
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if (comm->me == 0) {
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ptr = fgets(&line[n],MAXLINE-n,fp);
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if (ptr == NULL) {
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eof = 1;
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fclose(fp);
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} else n = strlen(line) + 1;
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}
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MPI_Bcast(&eof,1,MPI_INT,0,world);
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if (eof) break;
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MPI_Bcast(&n,1,MPI_INT,0,world);
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MPI_Bcast(line,n,MPI_CHAR,0,world);
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if ((ptr = strchr(line,'#'))) *ptr = '\0';
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nwords = atom->count_words(line);
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}
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if (nwords != params_per_line)
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error->all(FLERR,"Incorrect format in coul/streitz potential file");
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// words = ptrs to all words in line
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nwords = 0;
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words[nwords++] = strtok(line," \t\n\r\f");
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while ((words[nwords++] = strtok(NULL," \t\n\r\f"))) continue;
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// ielement = 1st args
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for (ielement = 0; ielement < nelements; ielement++)
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if (strcmp(words[0],elements[ielement]) == 0) break;
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if (ielement == nelements) continue;
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// load up parameter settings and error check their values
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if (nparams == maxparam) {
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maxparam += DELTA;
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params = (Param *) memory->srealloc(params,maxparam*sizeof(Param),
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"pair:params");
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}
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params[nparams].ielement = ielement;
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params[nparams].chi = atof(words[1]);
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params[nparams].eta = atof(words[2]);
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params[nparams].gamma = atof(words[3]);
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params[nparams].zeta = atof(words[4]);
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params[nparams].zcore = atof(words[5]);
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// parameter sanity check
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if (params[nparams].eta < 0.0 || params[nparams].zeta < 0.0 ||
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params[nparams].zcore < 0.0 || params[nparams].gamma != 0.0 )
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error->all(FLERR,"Illegal coul/streitz parameter");
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nparams++;
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}
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delete [] words;
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}
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/* ---------------------------------------------------------------------- */
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void PairCoulStreitz::setup_params()
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{
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int i,m,n;
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// set elem2param
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memory->destroy(elem2param);
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memory->create(elem2param,nelements,"pair:elem2param");
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for (i = 0; i < nelements; i++) {
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n = -1;
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for (m = 0; m < nparams; m++) {
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if (i == params[m].ielement ) {
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if (n >= 0) error->all(FLERR,"Potential file has duplicate entry");
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n = m;
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}
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}
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if (n < 0) error->all(FLERR,"Potential file is missing an entry");
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elem2param[i] = n;
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}
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// Wolf sum self energy
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if (kspacetype == 1) {
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double a = g_wolf;
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double r = cut_coul;
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double ar = a*r;
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woself = 0.50*erfc(ar)/r + a/MY_PIS; // kc constant not yet multiplied
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dwoself = -(erfc(ar)/r/r + 2.0*a/MY_PIS*exp(-ar*ar)/r);
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}
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}
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/* ---------------------------------------------------------------------- */
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void PairCoulStreitz::compute(int eflag, int vflag)
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{
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int i, j, ii, jj, inum, jnum;
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int itype, jtype, iparam_i,iparam_j;
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int *ilist, *jlist, *numneigh, **firstneigh;
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int *type = atom->type;
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int nlocal = atom->nlocal;
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int newton_pair = force->newton_pair;
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double xtmp, ytmp, ztmp, ecoul, fpair;
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double qi, qj, selfion, r, rsq, delr[3];
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double zei, zej, zj, ci_jfi, dci_jfi, ci_fifj, dci_fifj;
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double forcecoul, factor_coul;
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double **x = atom->x;
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double **f = atom->f;
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double *q = atom->q;
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double *special_coul = force->special_coul;
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ecoul = 0.0;
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selfion = fpair = 0.0;
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ci_jfi = ci_fifj = dci_jfi = dci_fifj = 0.0;
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forcecoul = 0.0;
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ev_init(eflag,vflag);
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inum = list->inum;
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ilist = list->ilist;
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numneigh = list->numneigh;
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firstneigh = list->firstneigh;
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// Wolf sum
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if (kspacetype == 1) {
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for (ii = 0; ii < inum; ii++) {
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i = ilist[ii];
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xtmp = x[i][0];
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ytmp = x[i][1];
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ztmp = x[i][2];
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itype = map[type[i]];
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iparam_i = elem2param[itype];
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qi = q[i];
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zei = params[iparam_i].zeta;
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// self energy: ionization + wolf sum
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selfion = self(¶ms[iparam_i],qi);
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if (evflag) ev_tally(i,i,nlocal,0,0.0,selfion,0.0,0.0,0.0,0.0);
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// two-body interaction
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jlist = firstneigh[i];
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jnum = numneigh[i];
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for (jj = 0; jj < jnum; jj++) {
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j = jlist[jj];
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j &= NEIGHMASK;
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jtype = map[type[j]];
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iparam_j = elem2param[jtype];
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qj = q[j];
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zej = params[iparam_j].zeta;
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zj = params[iparam_j].zcore;
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factor_coul = special_coul[sbmask(j)];
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delr[0] = xtmp - x[j][0];
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delr[1] = ytmp - x[j][1];
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delr[2] = ztmp - x[j][2];
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rsq = delr[0]*delr[0] + delr[1]*delr[1] + delr[2]*delr[2];
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if (rsq > cut_coulsq) continue;
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r = sqrt(rsq);
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// Streitz-Mintmire Coulomb integrals
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coulomb_integral_wolf(zei, zej, r, ci_jfi, dci_jfi, ci_fifj, dci_fifj);
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// Wolf Sum
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wolf_sum(qi, qj, zj, r, ci_jfi, dci_jfi, ci_fifj, dci_fifj,
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ecoul, forcecoul);
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// Forces
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fpair = -forcecoul / r;
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f[i][0] += delr[0]*fpair;
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f[i][1] += delr[1]*fpair;
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f[i][2] += delr[2]*fpair;
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if (newton_pair || j < nlocal) {
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f[j][0] -= delr[0]*fpair;
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f[j][1] -= delr[1]*fpair;
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f[j][2] -= delr[2]*fpair;
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}
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if (evflag) ev_tally(i,j,nlocal,newton_pair,
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0.0,ecoul,fpair,delr[0],delr[1],delr[2]);
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}
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}
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// Ewald Sum
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} else if (kspacetype == 2) {
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for (ii = 0; ii < inum; ii++) {
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i = ilist[ii];
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xtmp = x[i][0];
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ytmp = x[i][1];
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ztmp = x[i][2];
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itype = map[type[i]];
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iparam_i = elem2param[itype];
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qi = q[i];
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zei = params[iparam_i].zeta;
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// self ionizition energy, only on i atom
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selfion = self(¶ms[iparam_i],qi);
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if (evflag) ev_tally(i,i,nlocal,0,0.0,selfion,0.0,0.0,0.0,0.0);
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// two-body interaction
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jlist = firstneigh[i];
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jnum = numneigh[i];
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for (jj = 0; jj < jnum; jj++) {
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j = jlist[jj];
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j &= NEIGHMASK;
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jtype = map[type[j]];
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iparam_j = elem2param[jtype];
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qj = q[j];
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zej = params[iparam_j].zeta;
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zj = params[iparam_j].zcore;
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factor_coul = special_coul[sbmask(j)];
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delr[0] = xtmp - x[j][0];
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delr[1] = ytmp - x[j][1];
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delr[2] = ztmp - x[j][2];
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rsq = delr[0]*delr[0] + delr[1]*delr[1] + delr[2]*delr[2];
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if (rsq > cut_coulsq) continue;
|
|
|
|
r = sqrt(rsq);
|
|
|
|
// Streitz-Mintmire Coulomb integrals
|
|
|
|
coulomb_integral_ewald(zei, zej, r, ci_jfi, dci_jfi, ci_fifj, dci_fifj);
|
|
|
|
// Ewald: real-space
|
|
|
|
ewald_sum(qi, qj, zj, r, ci_jfi, dci_jfi, ci_fifj, dci_fifj,
|
|
ecoul, forcecoul, factor_coul);
|
|
|
|
// Forces
|
|
|
|
fpair = -forcecoul / r;
|
|
|
|
f[i][0] += delr[0]*fpair;
|
|
f[i][1] += delr[1]*fpair;
|
|
f[i][2] += delr[2]*fpair;
|
|
if (newton_pair || j < nlocal) {
|
|
f[j][0] -= delr[0]*fpair;
|
|
f[j][1] -= delr[1]*fpair;
|
|
f[j][2] -= delr[2]*fpair;
|
|
}
|
|
|
|
if (evflag) ev_tally(i,j,nlocal,newton_pair,
|
|
0.0,ecoul,fpair,delr[0],delr[1],delr[2]);
|
|
}
|
|
}
|
|
}
|
|
|
|
if (vflag_fdotr) virial_fdotr_compute();
|
|
}
|
|
|
|
/* ---------------------------------------------------------------------- */
|
|
|
|
double PairCoulStreitz::self(Param *param, double qi)
|
|
{
|
|
double s1=param->chi, s2=param->eta;
|
|
double qqrd2e = force->qqrd2e;
|
|
|
|
if (kspacetype == 1) return 1.0*qi*(s1+qi*(0.50*s2 - qqrd2e*woself));
|
|
|
|
if (kspacetype == 2) return 1.0*qi*(s1+qi*(0.50*s2));
|
|
|
|
return 0.0;
|
|
}
|
|
|
|
/* ---------------------------------------------------------------------- */
|
|
|
|
void PairCoulStreitz::coulomb_integral_wolf(double zei, double zej, double r,
|
|
double &ci_jfi, double &dci_jfi, double &ci_fifj,
|
|
double &dci_fifj)
|
|
{
|
|
double rinv = 1.0/r;
|
|
double rinv2 = rinv*rinv;
|
|
|
|
double exp2zir = exp(-2.0*zei*r);
|
|
double zei2 = zei*zei;
|
|
double zei4 = zei2*zei2;
|
|
double zei6 = zei2*zei4;
|
|
|
|
double exp2zjr = exp(-2.0*zej*r);
|
|
double zej2 = zej*zej;
|
|
double zej4 = zej2*zej2;
|
|
double zej6 = zej2*zej4;
|
|
|
|
double sm1 = 11.0/8.0;
|
|
double sm2 = 3.00/4.0;
|
|
double sm3 = 1.00/6.0;
|
|
double e1, e2, e3, e4;
|
|
|
|
double rc = cut_coul;
|
|
double rcinv = 1.0/rc;
|
|
double rcinv2 = rcinv*rcinv;
|
|
double exp2zirsh = exp(-2.0*zei*rc);
|
|
double exp2zjrsh = exp(-2.0*zej*rc);
|
|
double eshift, fshift;
|
|
|
|
e1 = e2 = e3 = e4 = 0.0;
|
|
|
|
eshift = -zei*exp2zirsh - rcinv*exp2zirsh;
|
|
fshift = 2.0*zei2*exp2zirsh + rcinv2*exp2zirsh + 2.0*zei*rcinv*exp2zirsh;
|
|
|
|
ci_jfi = -zei*exp2zir - rinv*exp2zir - eshift - (r-rc)*fshift;
|
|
dci_jfi = 2.0*zei2*exp2zir + rinv2*exp2zir + 2.0*zei*rinv*exp2zir - fshift;
|
|
|
|
if (zei == zej) {
|
|
|
|
eshift = -exp2zirsh*(rcinv + zei*(sm1 + sm2*zei*rc + sm3*zei2*rc*rc));
|
|
fshift = exp2zirsh*(rcinv2 + 2.0*zei*rcinv + zei2*
|
|
(2.0 + 7.0/6.0*zei*rc + 1.0/3.0*zei2*rc*rc));
|
|
|
|
ci_fifj = -exp2zir*(rinv + zei*(sm1 + sm2*zei*r + sm3*zei2*r*r))
|
|
- eshift - (r-rc)*fshift;
|
|
dci_fifj = exp2zir*(rinv2 + 2.0*zei*rinv + zei2*
|
|
(2.0 + 7.0/6.0*zei*r + 1.0/3.0*zei2*r*r)) - fshift;
|
|
|
|
} else {
|
|
|
|
e1 = zei*zej4/((zei+zej)*(zei+zej)*(zei-zej)*(zei-zej));
|
|
e2 = zej*zei4/((zei+zej)*(zei+zej)*(zej-zei)*(zej-zei));
|
|
e3 = (3.0*zei2*zej4-zej6) /
|
|
((zei+zej)*(zei+zej)*(zei+zej)*(zei-zej)*(zei-zej)*(zei-zej));
|
|
e4 = (3.0*zej2*zei4-zei6) /
|
|
((zei+zej)*(zei+zej)*(zei+zej)*(zej-zei)*(zej-zei)*(zej-zei));
|
|
|
|
eshift = -exp2zirsh*(e1+e3/rc) - exp2zjrsh*(e2+e4/rc);
|
|
fshift = (exp2zirsh*(2.0*zei*(e1+e3/rc) + e3*rcinv2)
|
|
+ exp2zjrsh*(2.0*zej*(e2+e4/rc) + e4*rcinv2));
|
|
|
|
ci_fifj = -exp2zir*(e1+e3/r) - exp2zjr*(e2+e4/r)
|
|
- eshift - (r-rc)*fshift;
|
|
dci_fifj = (exp2zir*(2.0*zei*(e1+e3/r) + e3*rinv2) +
|
|
exp2zjr*(2.0*zej*(e2+e4/r) + e4*rinv2)) - fshift;
|
|
}
|
|
}
|
|
|
|
/* ---------------------------------------------------------------------- */
|
|
|
|
void PairCoulStreitz::wolf_sum(double qi, double qj, double zj, double r,
|
|
double ci_jfi, double dci_jfi, double ci_fifj,
|
|
double dci_fifj, double &etmp, double &ftmp)
|
|
{
|
|
double a = g_wolf;
|
|
double rc = cut_coul;
|
|
double qqrd2e = force->qqrd2e;
|
|
|
|
double erfcr = erfc(a*r);
|
|
double derfcr = exp(-a*a*r*r);
|
|
double erfcrc = erfc(a*rc);
|
|
|
|
double etmp1, etmp2, etmp3;
|
|
double ftmp1, ftmp2, ftmp3;
|
|
|
|
etmp = etmp1 = etmp2 = etmp3 = 0.0;
|
|
ftmp = ftmp1 = ftmp2 = ftmp3 = 0.0;
|
|
|
|
etmp1 = erfcr/r - erfcrc/rc;
|
|
etmp2 = qi * zj * (ci_jfi - ci_fifj);
|
|
etmp3 = qi * qj * 0.50 * (etmp1 + ci_fifj);
|
|
|
|
ftmp1 = -erfcr/r/r - 2.0*a/MY_PIS*derfcr/r - dwoself;
|
|
ftmp2 = qi * zj * (dci_jfi - dci_fifj);
|
|
ftmp3 = qi * qj * 0.50 * (ftmp1 + dci_fifj);
|
|
|
|
etmp = qqrd2e * (etmp2 + etmp3);
|
|
ftmp = qqrd2e * (ftmp2 + ftmp3);
|
|
|
|
}
|
|
|
|
/* ---------------------------------------------------------------------- */
|
|
|
|
void PairCoulStreitz::coulomb_integral_ewald(double zei, double zej, double r,
|
|
double &ci_jfi, double &dci_jfi, double &ci_fifj,
|
|
double &dci_fifj)
|
|
{
|
|
double rinv = 1.0/r;
|
|
double rinv2 = rinv*rinv;
|
|
|
|
double exp2zir = exp(-2.0*zei*r);
|
|
double zei2 = zei*zei;
|
|
double zei4 = zei2*zei2;
|
|
double zei6 = zei2*zei4;
|
|
|
|
double exp2zjr = exp(-2.0*zej*r);
|
|
double zej2 = zej*zej;
|
|
double zej4 = zej2*zej2;
|
|
double zej6 = zej2*zej4;
|
|
|
|
double sm1 = 11.0/8.0;
|
|
double sm2 = 3.00/4.0;
|
|
double sm3 = 1.00/6.0;
|
|
|
|
double e1, e2, e3, e4;
|
|
e1 = e2 = e3 = e4 = 0.0;
|
|
|
|
ci_jfi = -zei*exp2zir - rinv*exp2zir;
|
|
dci_jfi = 2.0*zei2*exp2zir + rinv2*exp2zir + 2.0*zei*rinv*exp2zir;
|
|
|
|
if (zei == zej) {
|
|
|
|
ci_fifj = -exp2zir*(rinv + zei*(sm1 + sm2*zei*r + sm3*zei2*r*r));
|
|
dci_fifj = exp2zir*(rinv2 + 2.0*zei*rinv +
|
|
zei2*(2.0 + 7.0/6.0*zei*r + 1.0/3.0*zei2*r*r));
|
|
|
|
} else {
|
|
|
|
e1 = zei*zej4/((zei+zej)*(zei+zej)*(zei-zej)*(zei-zej));
|
|
e2 = zej*zei4/((zei+zej)*(zei+zej)*(zej-zei)*(zej-zei));
|
|
e3 = (3.0*zei2*zej4-zej6) /
|
|
((zei+zej)*(zei+zej)*(zei+zej)*(zei-zej)*(zei-zej)*(zei-zej));
|
|
e4 = (3.0*zej2*zei4-zei6) /
|
|
((zei+zej)*(zei+zej)*(zei+zej)*(zej-zei)*(zej-zei)*(zej-zei));
|
|
|
|
ci_fifj = -exp2zir*(e1+e3/r) - exp2zjr*(e2+e4/r);
|
|
dci_fifj = (exp2zir*(2.0*zei*(e1+e3/r) + e3*rinv2)
|
|
+ exp2zjr*(2.0*zej*(e2+e4/r) + e4*rinv2));
|
|
}
|
|
|
|
}
|
|
|
|
/* ---------------------------------------------------------------------- */
|
|
|
|
void PairCoulStreitz::ewald_sum(double qi, double qj, double zj, double r,
|
|
double ci_jfi, double dci_jfi, double ci_fifj,
|
|
double dci_fifj, double &etmp, double &ftmp, double fac)
|
|
{
|
|
double etmp1, etmp2, etmp3, etmp4;
|
|
double ftmp1, ftmp2, ftmp3, ftmp4;
|
|
|
|
double a = g_ewald;
|
|
double qqrd2e = force->qqrd2e;
|
|
|
|
double erfcr = erfc(a*r);
|
|
double derfcr = exp(-a*a*r*r);
|
|
|
|
etmp = ftmp = 0.0;
|
|
etmp1 = etmp2 = etmp3 = etmp4 = 0.0;
|
|
ftmp1 = ftmp2 = ftmp3 = ftmp4 = 0.0;
|
|
|
|
etmp1 = qi * zj * (ci_jfi - ci_fifj);
|
|
etmp2 = qi * qj * 0.50 * ci_fifj;
|
|
etmp3 = qqrd2e * (etmp1 + etmp2);
|
|
etmp4 = qqrd2e * 0.50*qi*qj/r;
|
|
|
|
ftmp1 = qi * zj * (dci_jfi - dci_fifj);
|
|
ftmp2 = qi * qj * 0.50 * dci_fifj;
|
|
ftmp3 = qqrd2e * (ftmp1 + ftmp2);
|
|
ftmp4 = etmp4 * (erfcr + 2.0/MY_PIS*a*r*derfcr);
|
|
|
|
etmp = erfcr*etmp4;
|
|
|
|
if (fac < 1.0) {
|
|
etmp -= (1.0-fac)*etmp4;
|
|
ftmp4 -= (1.0-fac)*etmp4;
|
|
}
|
|
|
|
etmp += etmp3;
|
|
ftmp = ftmp3 - ftmp4/r;
|
|
|
|
}
|
|
|
|
/* ----------------------------------------------------------------------
|
|
memory usage of local atom-based arrays
|
|
------------------------------------------------------------------------- */
|
|
|
|
double PairCoulStreitz::memory_usage()
|
|
{
|
|
double bytes = maxeatom * sizeof(double);
|
|
bytes += maxvatom*6 * sizeof(double);
|
|
bytes += nmax * sizeof(int);
|
|
bytes += MAXNEIGH * nmax * sizeof(int);
|
|
return bytes;
|
|
}
|
|
|
|
/* ---------------------------------------------------------------------- */
|
|
|
|
void *PairCoulStreitz::extract(const char *str, int &dim)
|
|
{
|
|
if (strcmp(str,"cut_coul") == 0) {
|
|
dim = 0;
|
|
return (void *) &cut_coul;
|
|
}
|
|
if (strcmp(str,"scale") == 0) {
|
|
dim = 2;
|
|
return (void *) scale;
|
|
}
|
|
if (strcmp(str,"chi") == 0 && qeq_x) {
|
|
dim = 1;
|
|
for (int i = 1; i <= atom->ntypes; i++)
|
|
if (map[i] >= 0) qeq_x[i] = params[map[i]].chi;
|
|
else qeq_x[i] = 0.0;
|
|
return (void *) qeq_x;
|
|
}
|
|
if (strcmp(str,"eta") == 0 && qeq_j) {
|
|
dim = 1;
|
|
for (int i = 1; i <= atom->ntypes; i++)
|
|
if (map[i] >= 0) qeq_j[i] = params[map[i]].eta;
|
|
else qeq_j[i] = 0.0;
|
|
return (void *) qeq_j;
|
|
}
|
|
if (strcmp(str,"gamma") == 0 && qeq_g) {
|
|
dim = 1;
|
|
for (int i = 1; i <= atom->ntypes; i++)
|
|
if (map[i] >= 0) qeq_g[i] = params[map[i]].gamma;
|
|
else qeq_g[i] = 0.0;
|
|
return (void *) qeq_g;
|
|
}
|
|
if (strcmp(str,"zeta") == 0 && qeq_z) {
|
|
dim = 1;
|
|
for (int i = 1; i <= atom->ntypes; i++)
|
|
if (map[i] >= 0) qeq_z[i] = params[map[i]].zeta;
|
|
else qeq_z[i] = 0.0;
|
|
return (void *) qeq_z;
|
|
}
|
|
if (strcmp(str,"zcore") == 0 && qeq_c) {
|
|
dim = 1;
|
|
for (int i = 1; i <= atom->ntypes; i++)
|
|
if (map[i] >= 0) qeq_c[i] = params[map[i]].zcore;
|
|
else qeq_c[i] = 0.0;
|
|
return (void *) qeq_c;
|
|
}
|
|
if (strcmp(str,"kspacetype") == 0) {
|
|
dim = 0;
|
|
return (void *) &kspacetype;
|
|
}
|
|
if (strcmp(str,"alpha") == 0) {
|
|
dim = 0;
|
|
if (kspacetype == 1) return (void *) &g_wolf;
|
|
if (kspacetype == 2) return (void *) &g_ewald;
|
|
}
|
|
return NULL;
|
|
}
|