818 lines
26 KiB
C++
818 lines
26 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: Alexander Stukowski (LLNL), alex@stukowski.com
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Will Tipton (Cornell), wwt26@cornell.edu
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Dallas R. Trinkle (UIUC), dtrinkle@illinois.edu
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Pinchao Zhang (UIUC)
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see LLNL copyright notice at bottom of file
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------------------------------------------------------------------------- */
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/* ----------------------------------------------------------------------
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* File history of changes:
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* 25-Oct-10 - AS: First code version.
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* 17-Feb-11 - AS: Several optimizations (introduced MEAM2Body struct).
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* 25-Mar-11 - AS: Fixed calculation of per-atom virial stress.
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* 11-Apr-11 - AS: Adapted code to new memory management of LAMMPS.
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* 24-Sep-11 - AS: Adapted code to new interface of Error::one() function.
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* 20-Jun-13 - WT: Added support for multiple species types
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* 25-Apr-17 - DRT/PZ: Modified format of multiple species type to
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conform with pairing, updated to LAMMPS style
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------------------------------------------------------------------------- */
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#include "pair_meam_spline.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 "force.h"
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#include "comm.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 "memory.h"
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#include "error.h"
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#include "utils.h"
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using namespace LAMMPS_NS;
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/* ---------------------------------------------------------------------- */
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PairMEAMSpline::PairMEAMSpline(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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nelements = 0;
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elements = NULL;
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Uprime_values = NULL;
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nmax = 0;
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maxNeighbors = 0;
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twoBodyInfo = NULL;
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comm_forward = 1;
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comm_reverse = 0;
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}
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/* ---------------------------------------------------------------------- */
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PairMEAMSpline::~PairMEAMSpline()
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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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delete[] twoBodyInfo;
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memory->destroy(Uprime_values);
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if(allocated) {
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memory->destroy(setflag);
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memory->destroy(cutsq);
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delete[] phis;
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delete[] Us;
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delete[] rhos;
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delete[] fs;
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delete[] gs;
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delete[] zero_atom_energies;
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delete [] map;
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}
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}
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/* ---------------------------------------------------------------------- */
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void PairMEAMSpline::compute(int eflag, int vflag)
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{
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const double* const * const x = atom->x;
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double* const * const forces = atom->f;
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const int ntypes = atom->ntypes;
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ev_init(eflag, vflag);
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// Grow per-atom array if necessary
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if (atom->nmax > nmax) {
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memory->destroy(Uprime_values);
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nmax = atom->nmax;
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memory->create(Uprime_values,nmax,"pair:Uprime");
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}
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// Determine the maximum number of neighbors a single atom has
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int newMaxNeighbors = 0;
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for(int ii = 0; ii < listfull->inum; ii++) {
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int jnum = listfull->numneigh[listfull->ilist[ii]];
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if(jnum > newMaxNeighbors)
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newMaxNeighbors = jnum;
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}
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// Allocate array for temporary bond info
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if(newMaxNeighbors > maxNeighbors) {
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maxNeighbors = newMaxNeighbors;
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delete[] twoBodyInfo;
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twoBodyInfo = new MEAM2Body[maxNeighbors];
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}
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// Sum three-body contributions to charge density and
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// the embedding energy
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for(int ii = 0; ii < listfull->inum; ii++) {
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int i = listfull->ilist[ii];
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int numBonds = 0;
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// compute charge density and numBonds
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MEAM2Body* nextTwoBodyInfo = twoBodyInfo;
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double rho_value = 0;
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const int ntypes = atom->ntypes;
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const int itype = atom->type[i];
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for(int jj = 0; jj < listfull->numneigh[i]; jj++) {
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int j = listfull->firstneigh[i][jj];
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j &= NEIGHMASK;
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double jdelx = x[j][0] - x[i][0];
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double jdely = x[j][1] - x[i][1];
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double jdelz = x[j][2] - x[i][2];
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double rij_sq = jdelx*jdelx + jdely*jdely + jdelz*jdelz;
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if(rij_sq < cutoff*cutoff) {
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double rij = sqrt(rij_sq);
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double partial_sum = 0;
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const int jtype = atom->type[j];
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nextTwoBodyInfo->tag = j;
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nextTwoBodyInfo->r = rij;
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nextTwoBodyInfo->f = fs[i_to_potl(jtype)].eval(rij, nextTwoBodyInfo->fprime);
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nextTwoBodyInfo->del[0] = jdelx / rij;
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nextTwoBodyInfo->del[1] = jdely / rij;
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nextTwoBodyInfo->del[2] = jdelz / rij;
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for(int kk = 0; kk < numBonds; kk++) {
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const MEAM2Body& bondk = twoBodyInfo[kk];
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double cos_theta = (nextTwoBodyInfo->del[0]*bondk.del[0] +
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nextTwoBodyInfo->del[1]*bondk.del[1] +
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nextTwoBodyInfo->del[2]*bondk.del[2]);
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partial_sum += bondk.f * gs[ij_to_potl(jtype,atom->type[bondk.tag],ntypes)].eval(cos_theta);
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}
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rho_value += nextTwoBodyInfo->f * partial_sum;
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rho_value += rhos[i_to_potl(jtype)].eval(rij);
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numBonds++;
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nextTwoBodyInfo++;
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}
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}
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// Compute embedding energy and its derivative
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double Uprime_i;
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double embeddingEnergy = Us[i_to_potl(itype)].eval(rho_value, Uprime_i)
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- zero_atom_energies[i_to_potl(itype)];
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Uprime_values[i] = Uprime_i;
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if(eflag) {
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if(eflag_global)
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eng_vdwl += embeddingEnergy;
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if(eflag_atom)
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eatom[i] += embeddingEnergy;
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}
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// Compute three-body contributions to force
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double forces_i[3] = {0, 0, 0};
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for(int jj = 0; jj < numBonds; jj++) {
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const MEAM2Body bondj = twoBodyInfo[jj];
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double rij = bondj.r;
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int j = bondj.tag;
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double f_rij_prime = bondj.fprime;
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double f_rij = bondj.f;
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double forces_j[3] = {0, 0, 0};
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const int jtype = atom->type[j];
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MEAM2Body const* bondk = twoBodyInfo;
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for(int kk = 0; kk < jj; kk++, ++bondk) {
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double rik = bondk->r;
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double cos_theta = (bondj.del[0]*bondk->del[0] +
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bondj.del[1]*bondk->del[1] +
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bondj.del[2]*bondk->del[2]);
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double g_prime;
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double g_value = gs[ij_to_potl(jtype,atom->type[bondk->tag],ntypes)].eval(cos_theta, g_prime);
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double f_rik_prime = bondk->fprime;
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double f_rik = bondk->f;
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double fij = -Uprime_i * g_value * f_rik * f_rij_prime;
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double fik = -Uprime_i * g_value * f_rij * f_rik_prime;
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double prefactor = Uprime_i * f_rij * f_rik * g_prime;
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double prefactor_ij = prefactor / rij;
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double prefactor_ik = prefactor / rik;
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fij += prefactor_ij * cos_theta;
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fik += prefactor_ik * cos_theta;
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double fj[3], fk[3];
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fj[0] = bondj.del[0] * fij - bondk->del[0] * prefactor_ij;
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fj[1] = bondj.del[1] * fij - bondk->del[1] * prefactor_ij;
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fj[2] = bondj.del[2] * fij - bondk->del[2] * prefactor_ij;
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forces_j[0] += fj[0];
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forces_j[1] += fj[1];
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forces_j[2] += fj[2];
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fk[0] = bondk->del[0] * fik - bondj.del[0] * prefactor_ik;
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fk[1] = bondk->del[1] * fik - bondj.del[1] * prefactor_ik;
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fk[2] = bondk->del[2] * fik - bondj.del[2] * prefactor_ik;
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forces_i[0] -= fk[0];
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forces_i[1] -= fk[1];
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forces_i[2] -= fk[2];
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int k = bondk->tag;
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forces[k][0] += fk[0];
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forces[k][1] += fk[1];
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forces[k][2] += fk[2];
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if(evflag) {
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double delta_ij[3];
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double delta_ik[3];
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delta_ij[0] = bondj.del[0] * rij;
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delta_ij[1] = bondj.del[1] * rij;
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delta_ij[2] = bondj.del[2] * rij;
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delta_ik[0] = bondk->del[0] * rik;
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delta_ik[1] = bondk->del[1] * rik;
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delta_ik[2] = bondk->del[2] * rik;
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ev_tally3(i, j, k, 0.0, 0.0, fj, fk, delta_ij, delta_ik);
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}
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}
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forces[i][0] -= forces_j[0];
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forces[i][1] -= forces_j[1];
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forces[i][2] -= forces_j[2];
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forces[j][0] += forces_j[0];
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forces[j][1] += forces_j[1];
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forces[j][2] += forces_j[2];
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}
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forces[i][0] += forces_i[0];
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forces[i][1] += forces_i[1];
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forces[i][2] += forces_i[2];
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}
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// Communicate U'(rho) values
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comm->forward_comm_pair(this);
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// Compute two-body pair interactions
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for(int ii = 0; ii < listhalf->inum; ii++) {
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int i = listhalf->ilist[ii];
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const int itype = atom->type[i];
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for(int jj = 0; jj < listhalf->numneigh[i]; jj++) {
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int j = listhalf->firstneigh[i][jj];
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j &= NEIGHMASK;
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double jdel[3];
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jdel[0] = x[j][0] - x[i][0];
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jdel[1] = x[j][1] - x[i][1];
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jdel[2] = x[j][2] - x[i][2];
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double rij_sq = jdel[0]*jdel[0] + jdel[1]*jdel[1] + jdel[2]*jdel[2];
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if(rij_sq < cutoff*cutoff) {
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double rij = sqrt(rij_sq);
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const int jtype = atom->type[j];
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double rho_prime_i,rho_prime_j;
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rhos[i_to_potl(itype)].eval(rij,rho_prime_i);
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rhos[i_to_potl(jtype)].eval(rij,rho_prime_j);
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double fpair = rho_prime_j * Uprime_values[i] + rho_prime_i*Uprime_values[j];
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double pair_pot_deriv;
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double pair_pot = phis[ij_to_potl(itype,jtype,ntypes)].eval(rij, pair_pot_deriv);
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fpair += pair_pot_deriv;
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// Divide by r_ij to get forces from gradient
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fpair /= rij;
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forces[i][0] += jdel[0]*fpair;
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forces[i][1] += jdel[1]*fpair;
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forces[i][2] += jdel[2]*fpair;
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forces[j][0] -= jdel[0]*fpair;
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forces[j][1] -= jdel[1]*fpair;
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forces[j][2] -= jdel[2]*fpair;
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if (evflag) ev_tally(i, j, atom->nlocal, force->newton_pair,
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pair_pot, 0.0, -fpair, jdel[0], jdel[1], jdel[2]);
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}
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}
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}
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if(vflag_fdotr)
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virial_fdotr_compute();
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}
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/* ---------------------------------------------------------------------- */
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void PairMEAMSpline::allocate()
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{
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allocated = 1;
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int n = nelements;
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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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int nmultichoose2 = n*(n+1)/2;
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//Change the functional form
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//f_ij->f_i
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//g_i(cos\theta_ijk)->g_jk(cos\theta_ijk)
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phis = new SplineFunction[nmultichoose2];
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Us = new SplineFunction[n];
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rhos = new SplineFunction[n];
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fs = new SplineFunction[n];
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gs = new SplineFunction[nmultichoose2];
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zero_atom_energies = new double[n];
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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 PairMEAMSpline::settings(int narg, char **/*arg*/)
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{
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if(narg != 0) error->all(FLERR,"Illegal pair_style command");
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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 PairMEAMSpline::coeff(int narg, char **arg)
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{
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int i,j,n;
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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 potential file: also sets the number of elements.
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read_file(arg[2]);
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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 ((nelements == 1) && (strlen(elements[0]) == 0)) {
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// old style: we only have one species, so we're either "NULL" or we match.
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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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else
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map[i-2] = 0;
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} else {
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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)
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break;
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if (j < nelements) map[i-2] = j;
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else error->all(FLERR,"No matching element in EAM potential file");
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}
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}
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// clear setflag since coeff() called once with I,J = * *
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n = atom->ntypes;
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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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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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#define MAXLINE 1024
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void PairMEAMSpline::read_file(const char* filename)
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{
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int nmultichoose2; // = (n+1)*n/2;
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if(comm->me == 0) {
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FILE *fp = force->open_potential(filename);
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if(fp == NULL) {
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char str[1024];
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snprintf(str,128,"Cannot open spline MEAM potential file %s", filename);
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error->one(FLERR,str);
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}
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// Skip first line of file. It's a comment.
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char line[MAXLINE];
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char *ptr;
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utils::sfgets(FLERR,line,MAXLINE,fp,filename,error);
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// Second line holds potential type ("meam/spline")
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// in new potential format.
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bool isNewFormat = false;
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utils::sfgets(FLERR,line,MAXLINE,fp,filename,error);
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ptr = strtok(line, " \t\n\r\f");
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if (strcmp(ptr, "meam/spline") == 0) {
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isNewFormat = true;
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// parse the rest of the line!
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ptr = strtok(NULL," \t\n\r\f");
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if (ptr == NULL)
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error->one(FLERR,"Need to include number of atomic species on"
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" meam/spline line in multi-element potential file");
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nelements = atoi(ptr);
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if (nelements < 1)
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error->one(FLERR, "Invalid number of atomic species on"
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" meam/spline line in potential file");
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elements = new char*[nelements];
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for (int i=0; i<nelements; ++i) {
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ptr = strtok(NULL," \t\n\r\f");
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if (ptr == NULL)
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error->one(FLERR, "Not enough atomic species in meam/spline"
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" line of multi-element potential file");
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elements[i] = new char[strlen(ptr)+1];
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strcpy(elements[i], ptr);
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}
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} else {
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isNewFormat = false;
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nelements = 1; // old format only handles one species; (backwards compatibility)
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elements = new char*[1];
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elements[0] = new char[1];
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strcpy(elements[0], "");
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rewind(fp);
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utils::sfgets(FLERR,line,MAXLINE,fp,filename,error);
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}
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nmultichoose2 = ((nelements+1)*nelements)/2;
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// allocate!!
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allocate();
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// Parse spline functions.
|
|
|
|
for (int i = 0; i < nmultichoose2; i++)
|
|
phis[i].parse(fp, error, isNewFormat);
|
|
for (int i = 0; i < nelements; i++)
|
|
rhos[i].parse(fp, error, isNewFormat);
|
|
for (int i = 0; i < nelements; i++)
|
|
Us[i].parse(fp, error, isNewFormat);
|
|
for (int i = 0; i < nelements; i++)
|
|
fs[i].parse(fp, error, isNewFormat);
|
|
for (int i = 0; i < nmultichoose2; i++)
|
|
gs[i].parse(fp, error, isNewFormat);
|
|
|
|
fclose(fp);
|
|
}
|
|
|
|
// Transfer spline functions from master processor to all other processors.
|
|
MPI_Bcast(&nelements, 1, MPI_INT, 0, world);
|
|
MPI_Bcast(&nmultichoose2, 1, MPI_INT, 0, world);
|
|
// allocate!!
|
|
if (comm->me != 0) {
|
|
allocate();
|
|
elements = new char*[nelements];
|
|
}
|
|
for (int i = 0; i < nelements; ++i) {
|
|
int n;
|
|
if (comm->me == 0)
|
|
n = strlen(elements[i]);
|
|
MPI_Bcast(&n, 1, MPI_INT, 0, world);
|
|
if (comm->me != 0)
|
|
elements[i] = new char[n+1];
|
|
MPI_Bcast(elements[i], n+1, MPI_CHAR, 0, world);
|
|
}
|
|
for (int i = 0; i < nmultichoose2; i++)
|
|
phis[i].communicate(world, comm->me);
|
|
for (int i = 0; i < nelements; i++)
|
|
rhos[i].communicate(world, comm->me);
|
|
for (int i = 0; i < nelements; i++)
|
|
fs[i].communicate(world, comm->me);
|
|
for (int i = 0; i < nelements; i++)
|
|
Us[i].communicate(world, comm->me);
|
|
for (int i = 0; i < nmultichoose2; i++)
|
|
gs[i].communicate(world, comm->me);
|
|
|
|
// Calculate 'zero-point energy' of single atom in vacuum.
|
|
for (int i = 0; i < nelements; i++)
|
|
zero_atom_energies[i] = Us[i].eval(0.0);
|
|
|
|
// Determine maximum cutoff radius of all relevant spline functions.
|
|
cutoff = 0.0;
|
|
for (int i = 0; i < nmultichoose2; i++)
|
|
if(phis[i].cutoff() > cutoff)
|
|
cutoff = phis[i].cutoff();
|
|
for (int i = 0; i < nelements; i++)
|
|
if(rhos[i].cutoff() > cutoff)
|
|
cutoff = rhos[i].cutoff();
|
|
for (int i = 0; i < nelements; i++)
|
|
if(fs[i].cutoff() > cutoff)
|
|
cutoff = fs[i].cutoff();
|
|
|
|
// Set LAMMPS pair interaction flags.
|
|
for(int i = 1; i <= atom->ntypes; i++) {
|
|
for(int j = 1; j <= atom->ntypes; j++) {
|
|
// setflag[i][j] = 1;
|
|
cutsq[i][j] = cutoff;
|
|
}
|
|
}
|
|
|
|
}
|
|
|
|
/* ----------------------------------------------------------------------
|
|
init specific to this pair style
|
|
------------------------------------------------------------------------- */
|
|
void PairMEAMSpline::init_style()
|
|
{
|
|
if(force->newton_pair == 0)
|
|
error->all(FLERR,"Pair style meam/spline requires newton pair on");
|
|
|
|
// Need both full and half neighbor list.
|
|
int irequest_full = neighbor->request(this,instance_me);
|
|
neighbor->requests[irequest_full]->id = 1;
|
|
neighbor->requests[irequest_full]->half = 0;
|
|
neighbor->requests[irequest_full]->full = 1;
|
|
int irequest_half = neighbor->request(this,instance_me);
|
|
neighbor->requests[irequest_half]->id = 2;
|
|
// neighbor->requests[irequest_half]->half = 1;
|
|
// neighbor->requests[irequest_half]->halffull = 1;
|
|
// neighbor->requests[irequest_half]->halffulllist = irequest_full;
|
|
}
|
|
|
|
/* ----------------------------------------------------------------------
|
|
neighbor callback to inform pair style of neighbor list to use
|
|
half or full
|
|
------------------------------------------------------------------------- */
|
|
void PairMEAMSpline::init_list(int id, NeighList *ptr)
|
|
{
|
|
if(id == 1) listfull = ptr;
|
|
else if(id == 2) listhalf = ptr;
|
|
}
|
|
|
|
/* ----------------------------------------------------------------------
|
|
init for one type pair i,j and corresponding j,i
|
|
------------------------------------------------------------------------- */
|
|
double PairMEAMSpline::init_one(int /*i*/, int /*j*/)
|
|
{
|
|
return cutoff;
|
|
}
|
|
|
|
/* ---------------------------------------------------------------------- */
|
|
|
|
int PairMEAMSpline::pack_forward_comm(int n, int *list, double *buf,
|
|
int /*pbc_flag*/, int * /*pbc*/)
|
|
{
|
|
int* list_iter = list;
|
|
int* list_iter_end = list + n;
|
|
while(list_iter != list_iter_end)
|
|
*buf++ = Uprime_values[*list_iter++];
|
|
return n;
|
|
}
|
|
|
|
/* ---------------------------------------------------------------------- */
|
|
|
|
void PairMEAMSpline::unpack_forward_comm(int n, int first, double *buf)
|
|
{
|
|
memcpy(&Uprime_values[first], buf, n * sizeof(buf[0]));
|
|
}
|
|
|
|
/* ---------------------------------------------------------------------- */
|
|
|
|
int PairMEAMSpline::pack_reverse_comm(int /*n*/, int /*first*/, double * /*buf*/)
|
|
{
|
|
return 0;
|
|
}
|
|
|
|
/* ---------------------------------------------------------------------- */
|
|
|
|
void PairMEAMSpline::unpack_reverse_comm(int /*n*/, int * /*list*/, double * /*buf*/)
|
|
{
|
|
}
|
|
|
|
/* ----------------------------------------------------------------------
|
|
Returns memory usage of local atom-based arrays
|
|
------------------------------------------------------------------------- */
|
|
double PairMEAMSpline::memory_usage()
|
|
{
|
|
return nmax * sizeof(double); // The Uprime_values array.
|
|
}
|
|
|
|
|
|
/// Parses the spline knots from a text file.
|
|
void PairMEAMSpline::SplineFunction::parse(FILE* fp, Error* error,
|
|
bool isNewFormat)
|
|
{
|
|
char line[MAXLINE];
|
|
|
|
// If new format, read the spline format. Should always be "spline3eq" for now.
|
|
if (isNewFormat)
|
|
utils::sfgets(FLERR,line,MAXLINE,fp,NULL,error);
|
|
|
|
// Parse number of spline knots.
|
|
utils::sfgets(FLERR,line,MAXLINE,fp,NULL,error);
|
|
int n = atoi(line);
|
|
if(n < 2)
|
|
error->one(FLERR,"Invalid number of spline knots in MEAM potential file");
|
|
|
|
// Parse first derivatives at beginning and end of spline.
|
|
utils::sfgets(FLERR,line,MAXLINE,fp,NULL,error);
|
|
double d0 = atof(strtok(line, " \t\n\r\f"));
|
|
double dN = atof(strtok(NULL, " \t\n\r\f"));
|
|
init(n, d0, dN);
|
|
|
|
// Skip line in old format
|
|
if (!isNewFormat)
|
|
utils::sfgets(FLERR,line,MAXLINE,fp,NULL,error);
|
|
|
|
// Parse knot coordinates.
|
|
for(int i=0; i<n; i++) {
|
|
utils::sfgets(FLERR,line,MAXLINE,fp,NULL,error);
|
|
double x, y, y2;
|
|
if(sscanf(line, "%lg %lg %lg", &x, &y, &y2) != 3) {
|
|
error->one(FLERR,"Invalid knot line in MEAM potential file");
|
|
}
|
|
setKnot(i, x, y);
|
|
}
|
|
|
|
prepareSpline(error);
|
|
}
|
|
|
|
/// Calculates the second derivatives at the knots of the cubic spline.
|
|
void PairMEAMSpline::SplineFunction::prepareSpline(Error* error)
|
|
{
|
|
xmin = X[0];
|
|
xmax = X[N-1];
|
|
|
|
isGridSpline = true;
|
|
h = (xmax-xmin)/(N-1);
|
|
hsq = h*h;
|
|
|
|
double* u = new double[N];
|
|
Y2[0] = -0.5;
|
|
u[0] = (3.0/(X[1]-X[0])) * ((Y[1]-Y[0])/(X[1]-X[0]) - deriv0);
|
|
for(int i = 1; i <= N-2; i++) {
|
|
double sig = (X[i]-X[i-1]) / (X[i+1]-X[i-1]);
|
|
double p = sig * Y2[i-1] + 2.0;
|
|
Y2[i] = (sig - 1.0) / p;
|
|
u[i] = (Y[i+1]-Y[i]) / (X[i+1]-X[i]) - (Y[i]-Y[i-1])/(X[i]-X[i-1]);
|
|
u[i] = (6.0 * u[i]/(X[i+1]-X[i-1]) - sig*u[i-1])/p;
|
|
|
|
if(fabs(h*i+xmin - X[i]) > 1e-8)
|
|
isGridSpline = false;
|
|
}
|
|
|
|
double qn = 0.5;
|
|
double un = (3.0/(X[N-1]-X[N-2])) * (derivN - (Y[N-1]-Y[N-2])/(X[N-1]-X[N-2]));
|
|
Y2[N-1] = (un - qn*u[N-2]) / (qn * Y2[N-2] + 1.0);
|
|
for(int k = N-2; k >= 0; k--) {
|
|
Y2[k] = Y2[k] * Y2[k+1] + u[k];
|
|
}
|
|
|
|
delete[] u;
|
|
|
|
#if !SPLINE_MEAM_SUPPORT_NON_GRID_SPLINES
|
|
if(!isGridSpline)
|
|
error->one(FLERR,"Support for MEAM potentials with non-uniform cubic splines has not been enabled in the MEAM potential code. Set SPLINE_MEAM_SUPPORT_NON_GRID_SPLINES in pair_spline_meam.h to 1 to enable it");
|
|
#endif
|
|
|
|
// Shift the spline to X=0 to speed up interpolation.
|
|
for(int i = 0; i < N; i++) {
|
|
Xs[i] = X[i] - xmin;
|
|
#if !SPLINE_MEAM_SUPPORT_NON_GRID_SPLINES
|
|
if(i < N-1) Ydelta[i] = (Y[i+1]-Y[i])/h;
|
|
Y2[i] /= h*6.0;
|
|
#endif
|
|
}
|
|
inv_h = (1/h);
|
|
xmax_shifted = xmax - xmin;
|
|
}
|
|
|
|
/// Broadcasts the spline function parameters to all processors.
|
|
void PairMEAMSpline::SplineFunction::communicate(MPI_Comm& world, int me)
|
|
{
|
|
MPI_Bcast(&N, 1, MPI_INT, 0, world);
|
|
MPI_Bcast(&deriv0, 1, MPI_DOUBLE, 0, world);
|
|
MPI_Bcast(&derivN, 1, MPI_DOUBLE, 0, world);
|
|
MPI_Bcast(&xmin, 1, MPI_DOUBLE, 0, world);
|
|
MPI_Bcast(&xmax, 1, MPI_DOUBLE, 0, world);
|
|
MPI_Bcast(&xmax_shifted, 1, MPI_DOUBLE, 0, world);
|
|
MPI_Bcast(&isGridSpline, 1, MPI_INT, 0, world);
|
|
MPI_Bcast(&h, 1, MPI_DOUBLE, 0, world);
|
|
MPI_Bcast(&hsq, 1, MPI_DOUBLE, 0, world);
|
|
MPI_Bcast(&inv_h, 1, MPI_DOUBLE, 0, world);
|
|
if(me != 0) {
|
|
X = new double[N];
|
|
Xs = new double[N];
|
|
Y = new double[N];
|
|
Y2 = new double[N];
|
|
Ydelta = new double[N];
|
|
}
|
|
MPI_Bcast(X, N, MPI_DOUBLE, 0, world);
|
|
MPI_Bcast(Xs, N, MPI_DOUBLE, 0, world);
|
|
MPI_Bcast(Y, N, MPI_DOUBLE, 0, world);
|
|
MPI_Bcast(Y2, N, MPI_DOUBLE, 0, world);
|
|
MPI_Bcast(Ydelta, N, MPI_DOUBLE, 0, world);
|
|
}
|
|
|
|
/// Writes a Gnuplot script that plots the spline function.
|
|
///
|
|
/// This function is for debugging only!
|
|
void PairMEAMSpline::SplineFunction::writeGnuplot(const char* filename,
|
|
const char* title) const
|
|
{
|
|
FILE* fp = fopen(filename, "w");
|
|
fprintf(fp, "#!/usr/bin/env gnuplot\n");
|
|
if(title) fprintf(fp, "set title \"%s\"\n", title);
|
|
double tmin = X[0] - (X[N-1] - X[0]) * 0.05;
|
|
double tmax = X[N-1] + (X[N-1] - X[0]) * 0.05;
|
|
double delta = (tmax - tmin) / (N*200);
|
|
fprintf(fp, "set xrange [%f:%f]\n", tmin, tmax);
|
|
fprintf(fp, "plot '-' with lines notitle, '-' with points notitle pt 3 lc 3\n");
|
|
for(double x = tmin; x <= tmax+1e-8; x += delta) {
|
|
double y = eval(x);
|
|
fprintf(fp, "%f %f\n", x, y);
|
|
}
|
|
fprintf(fp, "e\n");
|
|
for(int i = 0; i < N; i++) {
|
|
fprintf(fp, "%f %f\n", X[i], Y[i]);
|
|
}
|
|
fprintf(fp, "e\n");
|
|
fclose(fp);
|
|
}
|
|
|
|
/* ----------------------------------------------------------------------
|
|
* Spline-based Modified Embedded Atom method (MEAM) potential routine.
|
|
*
|
|
* Copyright (2011) Lawrence Livermore National Security, LLC.
|
|
* Produced at the Lawrence Livermore National Laboratory.
|
|
* Written by Alexander Stukowski (<alex@stukowski.com>).
|
|
* LLNL-CODE-525797 All rights reserved.
|
|
*
|
|
* This program is free software; you can redistribute it and/or modify it under
|
|
* the terms of the GNU General Public License (as published by the Free
|
|
* Software Foundation) version 2, dated June 1991.
|
|
*
|
|
* This program is distributed in the hope that it will be useful, but
|
|
* WITHOUT ANY WARRANTY; without even the IMPLIED WARRANTY OF MERCHANTABILITY
|
|
* or FITNESS FOR A PARTICULAR PURPOSE. See the terms and conditions of the
|
|
* GNU General Public License for more details.
|
|
*
|
|
* Our Preamble Notice
|
|
* A. This notice is required to be provided under our contract with the
|
|
* U.S. Department of Energy (DOE). This work was produced at the
|
|
* Lawrence Livermore National Laboratory under Contract No.
|
|
* DE-AC52-07NA27344 with the DOE.
|
|
*
|
|
* B. Neither the United States Government nor Lawrence Livermore National
|
|
* Security, LLC nor any of their employees, makes any warranty, express or
|
|
* implied, or assumes any liability or responsibility for the accuracy,
|
|
* completeness, or usefulness of any information, apparatus, product, or
|
|
* process disclosed, or represents that its use would not infringe
|
|
* privately-owned rights.
|
|
*
|
|
* C. Also, reference herein to any specific commercial products, process,
|
|
* or services by trade name, trademark, manufacturer or otherwise does not
|
|
* necessarily constitute or imply its endorsement, recommendation, or
|
|
* favoring by the United States Government or Lawrence Livermore National
|
|
* Security, LLC. The views and opinions of authors expressed herein do not
|
|
* necessarily state or reflect those of the United States Government or
|
|
* Lawrence Livermore National Security, LLC, and shall not be used for
|
|
* advertising or product endorsement purposes.
|
|
------------------------------------------------------------------------- */
|
|
|
|
|