git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@14661 f3b2605a-c512-4ea7-a41b-209d697bcdaa

src/pair_zero.cpp

@@ -0,0 +1,197 @@
+/* ----------------------------------------------------------------------
+   LAMMPS - Large-scale Atomic/Molecular Massively Parallel Simulator
+   http://lammps.sandia.gov, Sandia National Laboratories
+   Steve Plimpton, sjplimp@sandia.gov
+
+   Copyright (2003) Sandia Corporation.  Under the terms of Contract
+   DE-AC04-94AL85000 with Sandia Corporation, the U.S. Government retains
+   certain rights in this software.  This software is distributed under
+   the GNU General Public License.
+
+   See the README file in the top-level LAMMPS directory.
+------------------------------------------------------------------------- */
+
+/* ----------------------------------------------------------------------
+   Contributing author: Carsten Svaneborg (SDU)
+------------------------------------------------------------------------- */
+
+#include <math.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include "pair_zero.h"
+#include "atom.h"
+#include "comm.h"
+#include "force.h"
+#include "memory.h"
+#include "error.h"
+
+using namespace LAMMPS_NS;
+
+/* ---------------------------------------------------------------------- */
+
+PairZero::PairZero(LAMMPS *lmp) : Pair(lmp) {}
+
+/* ---------------------------------------------------------------------- */
+
+PairZero::~PairZero()
+{
+  if (allocated) {
+    memory->destroy(setflag);
+    memory->destroy(cutsq);
+    memory->destroy(cut);
+  }
+}
+
+/* ---------------------------------------------------------------------- */
+
+void PairZero::compute(int eflag, int vflag)
+{
+ if (eflag || vflag) ev_setup(eflag,vflag);
+  else evflag = vflag_fdotr = 0;
+  
+ if (vflag_fdotr) virial_fdotr_compute();
+}
+
+/* ----------------------------------------------------------------------
+   allocate all arrays
+------------------------------------------------------------------------- */
+
+void PairZero::allocate()
+{
+  allocated = 1;
+  int n = atom->ntypes;
+
+  memory->create(setflag,n+1,n+1,"pair:setflag");
+  for (int i = 1; i <= n; i++)
+    for (int j = i; j <= n; j++)
+      setflag[i][j] = 1;
+
+  memory->create(cutsq,n+1,n+1,"pair:cutsq");
+  memory->create(cut,n+1,n+1,"pair:cut");
+}
+
+/* ----------------------------------------------------------------------
+   global settings
+------------------------------------------------------------------------- */
+
+void PairZero::settings(int narg, char **arg)
+{
+  if (narg != 1) error->all(FLERR,"Illegal pair_style command");
+
+  cut_global = force->numeric(FLERR,arg[0]);
+
+  // reset cutoffs that have been explicitly set
+
+  allocate();
+  int i,j;
+  for (i = 1; i <= atom->ntypes; i++)
+    for (j = i+1; j <= atom->ntypes; j++)
+         cut[i][j] = cut_global;
+}
+
+/* ----------------------------------------------------------------------
+   set coeffs for one or more type pairs
+------------------------------------------------------------------------- */
+
+void PairZero::coeff(int narg, char **arg)
+{
+  if (narg < 2 || narg > 3)
+    error->all(FLERR,"Incorrect args for pair coefficients");
+  if (!allocated) allocate();
+
+  int ilo,ihi,jlo,jhi;
+  force->bounds(arg[0],atom->ntypes,ilo,ihi);
+  force->bounds(arg[1],atom->ntypes,jlo,jhi);
+
+  double cut_one = cut_global;
+  if (narg == 3) cut_one = force->numeric(FLERR,arg[2]);
+
+  int count = 0;
+  for (int i = ilo; i <= ihi; i++) {
+    for (int j = MAX(jlo,i); j <= jhi; j++) {
+      cut[i][j] = cut_one;
+      count++;
+    }
+  }
+
+  if (count == 0) error->all(FLERR,"Incorrect args for pair coefficients");
+}
+
+/* ----------------------------------------------------------------------
+   init for one type pair i,j and corresponding j,i
+------------------------------------------------------------------------- */
+
+double PairZero::init_one(int i, int j)
+{
+  if (setflag[i][j] == 0) {
+    cut[i][j] = mix_distance(cut[i][i],cut[j][j]);
+  }
+
+  return cut[i][j];
+}
+
+/* ----------------------------------------------------------------------
+   proc 0 writes to restart file
+------------------------------------------------------------------------- */
+
+void PairZero::write_restart(FILE *fp)
+{
+  write_restart_settings(fp);
+
+  int i,j;
+  for (i = 1; i <= atom->ntypes; i++)
+    for (j = i; j <= atom->ntypes; j++) {
+      fwrite(&setflag[i][j],sizeof(int),1,fp);
+      if (setflag[i][j]) {
+        fwrite(&cut[i][j],sizeof(double),1,fp);
+      }
+    }
+}
+
+/* ----------------------------------------------------------------------
+   proc 0 reads from restart file, bcasts
+------------------------------------------------------------------------- */
+
+void PairZero::read_restart(FILE *fp)
+{
+  read_restart_settings(fp);
+  allocate();
+
+  int i,j;
+  int me = comm->me;
+  for (i = 1; i <= atom->ntypes; i++)
+    for (j = i; j <= atom->ntypes; j++) {
+      if (me == 0) fread(&setflag[i][j],sizeof(int),1,fp);
+      MPI_Bcast(&setflag[i][j],1,MPI_INT,0,world);
+      if (setflag[i][j]) {
+        if (me == 0) {
+          fread(&cut[i][j],sizeof(double),1,fp);
+        }
+        MPI_Bcast(&cut[i][j],1,MPI_DOUBLE,0,world);
+      }
+    }
+}
+
+/* ----------------------------------------------------------------------
+   proc 0 writes to restart file
+------------------------------------------------------------------------- */
+
+void PairZero::write_restart_settings(FILE *fp)
+{
+  fwrite(&cut_global,sizeof(double),1,fp);
+}
+
+/* ----------------------------------------------------------------------
+   proc 0 reads from restart file, bcasts
+------------------------------------------------------------------------- */
+
+void PairZero::read_restart_settings(FILE *fp)
+{
+  int me = comm->me;
+  if (me == 0) {
+    fread(&cut_global,sizeof(double),1,fp);
+  }
+  MPI_Bcast(&cut_global,1,MPI_DOUBLE,0,world);
+}
+