Commit 71c4edda authored by vishalkenchan's avatar vishalkenchan
Browse files

add coul/wolf/cs and born/coul/wolf/cs pair styles for CORESHELL package

parent 40147a7a
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+15 −9
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@@ -30,6 +30,7 @@ action () {

action compute_temp_cs.cpp
action compute_temp_cs.h

action pair_born_coul_long_cs.cpp   pair_born_coul_long.cpp
action pair_born_coul_dsf_cs.cpp    pair_born_coul_dsf.cpp
action pair_buck_coul_long_cs.cpp   pair_buck_coul_long.cpp
@@ -40,3 +41,8 @@ action pair_coul_long_cs.cpp pair_coul_long.cpp
action pair_coul_long_cs.h          pair_coul_long.h
action pair_lj_cut_coul_long_cs.cpp pair_lj_cut_coul_long.cpp
action pair_lj_cut_coul_long_cs.h   pair_lj_cut_coul_long.h

action pair_born_coul_wolf_cs.cpp   pair_born_coul_wolf.cpp
action pair_born_coul_wolf_cs.h     pair_born_coul_wolf.h
action pair_coul_wolf_cs.cpp        pair_coul_wolf.cpp
action pair_coul_wolf_cs.h          pair_coul_wolf.h
+170 −0
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/* ----------------------------------------------------------------------
   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.
------------------------------------------------------------------------- */


#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "pair_born_coul_wolf_cs.h"
#include "atom.h"
#include "comm.h"
#include "force.h"
#include "neighbor.h"
#include "neigh_list.h"
#include "math_const.h"
#include "math_special.h"
#include "memory.h"
#include "error.h"

using namespace LAMMPS_NS;
using namespace MathConst;
using namespace MathSpecial;

#define EPSILON 1.0e-20

/* ---------------------------------------------------------------------- */

PairBornCoulWolfCS::PairBornCoulWolfCS(LAMMPS *lmp) : PairBornCoulWolf(lmp)
{
  single_enable = 0;
}

/* ---------------------------------------------------------------------- */

void PairBornCoulWolfCS::compute(int eflag, int vflag)
{
  int i,j,ii,jj,inum,jnum,itype,jtype;
  double qtmp,xtmp,ytmp,ztmp,delx,dely,delz,evdwl,ecoul,fpair;
  double rsq,r2inv,r6inv,forcecoul,forceborn,factor_coul,factor_lj;
  double prefactor;
  double r,rexp;
  int *ilist,*jlist,*numneigh,**firstneigh;
  double erfcc,erfcd,v_sh,dvdrr,e_self,e_shift,f_shift,qisq;

  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;

  // self and shifted coulombic energy

  e_self = v_sh = 0.0;
  e_shift = erfc(alf*cut_coul)/cut_coul;
  f_shift = -(e_shift+ 2.0*alf/MY_PIS * exp(-alf*alf*cut_coul*cut_coul)) /
    cut_coul;

  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];
    qtmp = q[i];
    xtmp = x[i][0];
    ytmp = x[i][1];
    ztmp = x[i][2];
    itype = type[i];
    jlist = firstneigh[i];
    jnum = numneigh[i];

    qisq = qtmp*qtmp;
    e_self = -(e_shift/2.0 + alf/MY_PIS) * qisq*qqrd2e;
    if (eflag) ev_tally(i,i,nlocal,0,0.0,e_self,0.0,0.0,0.0,0.0);

    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]) {
	rsq += EPSILON;
	// Add EPISLON for case: r = 0; Interaction must be removed
	// by special bond
        r2inv = 1.0/rsq;

        if (rsq < cut_coulsq) {
          r = sqrt(rsq);
          prefactor = qqrd2e*qtmp*q[j]/r;
          erfcc = erfc(alf*r);
          erfcd = exp(-alf*alf*r*r);
          v_sh = (erfcc - e_shift*r) * prefactor;
          dvdrr = (erfcc/rsq + 2.0*alf/MY_PIS * erfcd/r) + f_shift;
          forcecoul = dvdrr*rsq*prefactor;
          if (factor_coul < 1.0) forcecoul -= (1.0-factor_coul)*prefactor;
        } else forcecoul = 0.0;

        if (rsq < cut_ljsq[itype][jtype]) {
          r6inv = r2inv*r2inv*r2inv;
          r = sqrt(rsq);
          rexp = exp((sigma[itype][jtype]-r)*rhoinv[itype][jtype]);
          forceborn = born1[itype][jtype]*r*rexp - born2[itype][jtype]*r6inv
            + born3[itype][jtype]*r2inv*r6inv;
        } else forceborn = 0.0;

        fpair = (forcecoul + factor_lj*forceborn) * 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) {
            ecoul = v_sh;
            if (factor_coul < 1.0) ecoul -= (1.0-factor_coul)*prefactor;
          } else ecoul = 0.0;
          if (rsq < cut_ljsq[itype][jtype]) {
            evdwl = a[itype][jtype]*rexp - c[itype][jtype]*r6inv +
              d[itype][jtype]*r6inv*r2inv - 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();
}

/*
Using erfc and expmsq provided by math_special.h

See: http://lammps.sandia.gov/threads/msg61934.html
*/
+60 −0
Original line number Diff line number Diff line
/* ----------------------------------------------------------------------
   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.
------------------------------------------------------------------------- */

#ifdef PAIR_CLASS

PairStyle(born/coul/wolf/cs,PairBornCoulWolfCS)

#else

#ifndef LMP_PAIR_BORN_COUL_WOLF_CS_H
#define LMP_PAIR_BORN_COUL_WOLF_CS_H

#include "pair_born_coul_wolf.h"

namespace LAMMPS_NS {

class PairBornCoulWolfCS : public PairBornCoulWolf {
 public:
  PairBornCoulWolfCS(class LAMMPS *);
  virtual void compute(int, int);
};

}

#endif
#endif

/* ERROR/WARNING messages:

E: Illegal ... command

Self-explanatory.  Check the input script syntax and compare to the
documentation for the command.  You can use -echo screen as a
command-line option when running LAMMPS to see the offending line.

E: Incorrect args for pair coefficients

Self-explanatory.  Check the input script or data file.

E: All pair coeffs are not set

All pair coefficients must be set in the data file or by the
pair_coeff command before running a simulation.

E: Pair style born/coul/wolf/cs requires atom attribute q

An atom style that defines this attribute must be used.


*/
+145 −0
Original line number Diff line number Diff line
/* ----------------------------------------------------------------------
   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.
------------------------------------------------------------------------- */


#include <math.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "pair_coul_wolf_cs.h"
#include "atom.h"
#include "comm.h"
#include "force.h"
#include "neighbor.h"
#include "neigh_list.h"
#include "math_const.h"
#include "math_special.h"
#include "memory.h"
#include "error.h"

using namespace LAMMPS_NS;
using namespace MathConst;
using namespace MathSpecial;

#define EPSILON 1.0e-20

/* ---------------------------------------------------------------------- */

PairCoulWolfCS::PairCoulWolfCS(LAMMPS *lmp) : PairCoulWolf( lmp )
{
   single_enable = 0;
}

/* ---------------------------------------------------------------------- */

void PairCoulWolfCS::compute(int eflag, int vflag)
{
  int i,j,ii,jj,inum,jnum;
  double qtmp,xtmp,ytmp,ztmp,delx,dely,delz,ecoul,fpair;
  double rsq,forcecoul,factor_coul;
  double prefactor;
  double r;
  int *ilist,*jlist,*numneigh,**firstneigh;
  double erfcc,erfcd,v_sh,dvdrr,e_self,e_shift,f_shift,qisq;

  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 nlocal = atom->nlocal;
  double *special_coul = force->special_coul;
  int newton_pair = force->newton_pair;
  double qqrd2e = force->qqrd2e;

  // self and shifted coulombic energy

  e_self = v_sh = 0.0;
  e_shift = erfc(alf*cut_coul)/cut_coul;
  f_shift = -(e_shift+ 2.0*alf/MY_PIS * exp(-alf*alf*cut_coul*cut_coul)) /
    cut_coul;

  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];
    qtmp = q[i];
    xtmp = x[i][0];
    ytmp = x[i][1];
    ztmp = x[i][2];
    jlist = firstneigh[i];
    jnum = numneigh[i];

    qisq = qtmp*qtmp;
    e_self = -(e_shift/2.0 + alf/MY_PIS) * qisq*qqrd2e;
    if (evflag) ev_tally(i,i,nlocal,0,0.0,e_self,0.0,0.0,0.0,0.0);

    for (jj = 0; jj < jnum; jj++) {
      j = jlist[jj];
      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;

      if (rsq < cut_coulsq) {
	rsq += EPSILON;
	// Add EPISLON for case: r = 0; Interaction must be removed
	// by special bond
	r = sqrt(rsq);
	prefactor = qqrd2e*qtmp*q[j]/r;
	erfcc = erfc(alf*r);
	erfcd = exp(-alf*alf*r*r);
	v_sh = (erfcc - e_shift*r) * prefactor;
	dvdrr = (erfcc/rsq + 2.0*alf/MY_PIS * erfcd/r) + f_shift;
	forcecoul = dvdrr*rsq*prefactor;
	if (factor_coul < 1.0) forcecoul -= (1.0-factor_coul)*prefactor;
	fpair = forcecoul / rsq;

	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) {
	  ecoul = v_sh;
	  if (factor_coul < 1.0) ecoul -= (1.0-factor_coul)*prefactor;
	} else ecoul = 0.0;

	if (evflag) ev_tally(i,j,nlocal,newton_pair,
			     0.0,ecoul,fpair,delx,dely,delz);
      }
    }
  }

  if (vflag_fdotr) virial_fdotr_compute();
}

/* NOTES
Using erfc and expmsq provided by math_special.h

See: http://lammps.sandia.gov/threads/msg61934.html
*/
+54 −0
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/* -*- 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.
------------------------------------------------------------------------- */

#ifdef PAIR_CLASS

PairStyle(coul/wolf/cs,PairCoulWolfCS)

#else

#ifndef LMP_PAIR_COUL_WOLF_CS_H_
#define LMP_PAIR_COUL_WOLF_CS_H_

#include "pair_coul_wolf.h"

namespace LAMMPS_NS {

class PairCoulWolfCS : public PairCoulWolf {
 public:
  PairCoulWolfCS( class LAMMPS *);
  virtual void compute( int, int);
};

}

#endif
#endif /* LMP_PAIR_COUL_WOLF_CS_H_ */

/* ERROR/WARNING messages:

E: Illegal ... command

Self-explanatory.  Check the input script syntax and compare to the
documentation for the command.  You can use -echo screen as a
command-line option when running LAMMPS to see the offending line.

E: Incorrect args for pair coefficients

Self-explanatory.  Check the input script or data file.

E: Pair coul/wolf/cs requires atom attribute q

The atom style defined does not have this attribute.

*/