git-svn-id: svn://svn.icms.temple.edu/lammps-ro/trunk@5103 f3b2605a-c512-4ea7-a41b-209d697bcdaa

src/compute_ti.cpp

@@ -0,0 +1,180 @@
+/* ----------------------------------------------------------------------
+   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: Sai Jayaraman (University of Notre Dame)
+------------------------------------------------------------------------- */
+
+#include "mpi.h"
+#include "string.h"
+#include "compute_ti.h"
+#include "update.h"
+#include "modify.h"
+#include "domain.h"
+#include "force.h"
+#include "pair.h"
+#include "kspace.h"
+#include "input.h"
+#include "variable.h"
+#include "error.h"
+
+using namespace LAMMPS_NS;
+
+enum{PAIR,TAIL,KSPACE};
+
+#define INVOKED_SCALAR 1
+
+/* ---------------------------------------------------------------------- */
+
+ComputeTI::ComputeTI(LAMMPS *lmp, int narg, char **arg) : 
+  Compute(lmp, narg, arg) 
+{ 
+  if (narg < 4) error->all("Illegal compute ti command");
+
+  peflag = 1;
+  scalar_flag = 1;
+  extscalar = 1;
+  timeflag = 1;
+
+  // terms come in triplets
+
+  nterms = (narg-3) / 3;
+  if (narg != 3*nterms + 3) error->all("Illegal compute ti command");
+
+  which = new int[nterms];
+  ivar1 = new int[nterms];
+  ivar2 = new int[nterms];
+  var1 = new char*[nterms];
+  var2 = new char*[nterms];
+  pptr = new Pair*[nterms];
+  pstyle = new char*[nterms];
+
+  for (int m = 0; m < nterms; m++) pstyle[m] = NULL;
+    
+  // parse keywords
+
+  nterms = 0;
+
+  int iarg = 3;
+  while (iarg < narg) {
+    if (iarg+3 > narg) error->all("Illegal fix adapt command");
+    if (strcmp(arg[iarg],"kspace") == 0) which[nterms] = KSPACE;
+    else if (strcmp(arg[iarg],"tail") == 0) which[nterms] = TAIL;
+    else {
+      which[nterms] = PAIR;
+      int n = strlen(&arg[iarg+1][2]) + 1;
+      pstyle[nterms] = new char[n];
+      strcpy(pstyle[nterms],&arg[iarg+1][2]);
+    }
+
+    if (strstr(arg[iarg+2],"v_") == arg[iarg+2]) {
+      int n = strlen(&arg[iarg+2][2]) + 1;
+      var1[nterms] = new char[n];
+      strcpy(var1[nterms],&arg[iarg+2][2]);
+    } else error->all("Illegal compute ti command");
+    if (strstr(arg[iarg+3],"v_") == arg[iarg+3]) {
+      int n = strlen(&arg[iarg+3][2]) + 1;
+      var2[nterms] = new char[n];
+      strcpy(var2[nterms],&arg[iarg+3][2]);
+    } else error->all("Illegal compute ti command");
+
+    nterms++;
+    iarg += 3;
+  }
+}
+
+/* --------------------------------------------------------------------- */
+
+ComputeTI::~ComputeTI()
+{
+  for (int m = 0; m < nterms; m++) {
+    delete [] var1[m];
+    delete [] var2[m];
+    delete [] pstyle[m];
+  }
+  delete [] which;
+  delete [] ivar1;
+  delete [] ivar2;
+  delete [] var1;
+  delete [] var2;
+  delete [] pptr;
+  delete [] pstyle;
+}
+
+/* --------------------------------------------------------------------- */
+
+void ComputeTI::init()
+{
+  // setup and error checks
+
+  for (int m = 0; m < nterms; m++) {
+    ivar1[m] = input->variable->find(var1[m]);
+    ivar2[m] = input->variable->find(var2[m]);
+    if (ivar1[m] < 0 || ivar2 < 0)
+      error->all("Variable name for compute ti does not exist");
+    if (!input->variable->equalstyle(ivar1[m]) ||
+	!input->variable->equalstyle(ivar2[m]))
+      error->all("Variable for compute ti is invalid style");
+
+    if (which[m] == PAIR) {
+      pptr[m] = force->pair_match(pstyle[m],1);
+      if (pptr[m] == NULL) error->all("Compute ti pair style does not exist");
+
+    } else if (which[m] == TAIL) {
+      if (force->pair == NULL || force->pair->tail_flag == 0) 
+	error->all("Compute ti tail when pair style does not "
+		   "compute tail corrections");
+
+    } else if (which[m] == KSPACE) {
+      if (force->kspace == NULL) 
+	error->all("Compute ti is incompatible with KSpace style");
+    }
+  }
+}
+
+/* --------------------------------------------------------------------- */
+
+double ComputeTI::compute_scalar()
+{
+  double eng,engall,value1,value2;
+
+  invoked_scalar |= INVOKED_SCALAR;
+  if (update->eflag_global != invoked_scalar)
+    error->all("Energy was not tallied on needed timestep");
+
+  double dUdl = 0.0;
+
+  for (int m = 0; m < nterms; m++) {
+    value1 = input->variable->compute_equal(ivar1[m]);
+    value2 = input->variable->compute_equal(ivar2[m]);
+    if (value1 == 0.0) continue;
+
+    if (which[m] == PAIR) {
+      eng = pptr[m]->eng_vdwl + pptr[m]->eng_coul;
+      MPI_Allreduce(&eng,&engall,1,MPI_DOUBLE,MPI_SUM,world);
+      dUdl += engall/value1 * value2;
+
+    } else if (which[m] == TAIL) {
+      double vol = domain->xprd*domain->yprd*domain->zprd;
+      eng = force->pair->etail / vol;
+      dUdl += eng/value1 * value2;
+
+    } else if (which[m] == KSPACE) {
+      eng = force->kspace->energy;
+      dUdl += eng/value1 * value2;
+    }
+  }
+
+  scalar = dUdl;
+  return scalar;
+}