randomBuilder.cpp

/*
 * Copyright (c) 2004-present, The University of Notre Dame. All rights
 * reserved.
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 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
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 *    contributors may be used to endorse or promote products derived from
 *    this software without specific prior written permission.
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 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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 * POSSIBILITY OF SUCH DAMAGE.
 *
 * SUPPORT OPEN SCIENCE!  If you use OpenMD or its source code in your
 * research, please cite the appropriate papers when you publish your
 * work.  Good starting points are:
 *
 * [1] Meineke, et al., J. Comp. Chem. 26, 252-271 (2005).
 * [2] Fennell & Gezelter, J. Chem. Phys. 124, 234104 (2006).
 * [3] Sun, Lin & Gezelter, J. Chem. Phys. 128, 234107 (2008).
 * [4] Vardeman, Stocker & Gezelter, J. Chem. Theory Comput. 7, 834 (2011).
 * [5] Kuang & Gezelter, Mol. Phys., 110, 691-701 (2012).
 * [6] Lamichhane, Gezelter & Newman, J. Chem. Phys. 141, 134109 (2014).
 * [7] Lamichhane, Newman & Gezelter, J. Chem. Phys. 141, 134110 (2014).
 * [8] Bhattarai, Newman & Gezelter, Phys. Rev. B 99, 094106 (2019).
 */
 
#include <cmath>
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <fstream>
#include <iostream>
#include <map>
#include <random>
#include <string>
 
#include "brains/Register.hpp"
#include "brains/SimCreator.hpp"
#include "brains/SimInfo.hpp"
#include "io/DumpWriter.hpp"
#include "lattice/Lattice.hpp"
#include "lattice/LatticeFactory.hpp"
#include "math/SquareMatrix3.hpp"
#include "math/Vector3.hpp"
#include "randomBuilderCmd.hpp"
#include "utils/MoLocator.hpp"
#include "utils/StringUtils.hpp"
 
using namespace std;
using namespace OpenMD;
 
void createMdFile(const std::string& oldMdFileName,
                  const std::string& newMdFileName, std::vector<int> nMol);
 
int main(int argc, char* argv[]) {
  registerLattice();
 
  gengetopt_args_info args_info;
  std::string latticeType;
  std::string inputFileName;
  std::string outputFileName;
  Lattice* simpleLat;
  RealType latticeConstant;
  std::vector<RealType> lc;
  const RealType rhoConvertConst = 1.661;
  RealType density;
  int nx, ny, nz;
  Mat3x3d hmat;
  MoLocator* locator;
  std::vector<Vector3d> latticePos;
  std::vector<Vector3d> latticeOrt;
  int nMolPerCell;
  DumpWriter* writer;
 
  // parse command line arguments
  if (cmdline_parser(argc, argv, &args_info) != 0) exit(1);
 
  density = args_info.density_arg;
 
  // get lattice type
  latticeType = "FCC";
  if (args_info.lattice_given) { latticeType = args_info.lattice_arg; }
 
  simpleLat = LatticeFactory::getInstance().createLattice(latticeType);
 
  if (simpleLat == NULL) {
    snprintf(painCave.errMsg, MAX_SIM_ERROR_MSG_LENGTH,
             "Lattice Factory can not create %s lattice\n",
             latticeType.c_str());
    painCave.isFatal = 1;
    simError();
  }
  nMolPerCell = simpleLat->getNumSitesPerCell();
 
  // get the number of unit cells in each direction:
 
  nx = args_info.nx_arg;
 
  if (nx <= 0) {
    snprintf(painCave.errMsg, MAX_SIM_ERROR_MSG_LENGTH,
             "The number of unit cells in the x direction "
             "must be greater than 0.");
    painCave.isFatal = 1;
    simError();
  }
 
  ny = args_info.ny_arg;
 
  if (ny <= 0) {
    snprintf(painCave.errMsg, MAX_SIM_ERROR_MSG_LENGTH,
             "The number of unit cells in the y direction "
             "must be greater than 0.");
    painCave.isFatal = 1;
    simError();
  }
 
  nz = args_info.nz_arg;
 
  if (nz <= 0) {
    snprintf(painCave.errMsg, MAX_SIM_ERROR_MSG_LENGTH,
             "The number of unit cells in the z direction "
             "must be greater than 0.");
    painCave.isFatal = 1;
    simError();
  }
 
  int nSites = nMolPerCell * nx * ny * nz;
 
  // get input file name
  if (args_info.inputs_num)
    inputFileName = args_info.inputs[0];
  else {
    snprintf(painCave.errMsg, MAX_SIM_ERROR_MSG_LENGTH,
             "No input .omd file name was specified "
             "on the command line");
    painCave.isFatal = 1;
    simError();
  }
 
  // parse md file and set up the system
 
  SimCreator oldCreator;
  SimInfo* oldInfo   = oldCreator.createSim(inputFileName, false);
  Globals* simParams = oldInfo->getSimParams();
 
  // Calculate lattice constant (in Angstroms)
 
  std::vector<Component*> components = simParams->getComponents();
  std::vector<RealType> molFractions;
  std::vector<RealType> molecularMasses;
  std::vector<int> nMol;
  std::size_t nComponents = components.size();
 
  if (nComponents == 1) {
    molFractions.push_back(1.0);
  } else {
    if (args_info.molFraction_given == nComponents) {
      for (std::size_t i = 0; i < nComponents; i++) {
        molFractions.push_back(args_info.molFraction_arg[i]);
      }
    } else if (args_info.molFraction_given == nComponents - 1) {
      RealType remainingFraction = 1.0;
      for (std::size_t i = 0; i < nComponents - 1; i++) {
        molFractions.push_back(args_info.molFraction_arg[i]);
        remainingFraction -= molFractions[i];
      }
      molFractions.push_back(remainingFraction);
    } else {
      snprintf(painCave.errMsg, MAX_SIM_ERROR_MSG_LENGTH,
               "randomBuilder can't figure out molFractions "
               "for all of the components in the <MetaData> block.");
      painCave.isFatal = 1;
      simError();
    }
  }
 
  // do some sanity checking:
 
  RealType totalFraction = 0.0;
 
  for (std::size_t i = 0; i < nComponents; i++) {
    if (molFractions.at(i) < 0.0) {
      snprintf(painCave.errMsg, MAX_SIM_ERROR_MSG_LENGTH,
               "One of the requested molFractions was"
               " less than zero!");
      painCave.isFatal = 1;
      simError();
    }
    if (molFractions.at(i) > 1.0) {
      snprintf(painCave.errMsg, MAX_SIM_ERROR_MSG_LENGTH,
               "One of the requested molFractions was"
               " greater than one!");
      painCave.isFatal = 1;
      simError();
    }
    totalFraction += molFractions.at(i);
  }
  if (abs(totalFraction - 1.0) > 1e-6) {
    snprintf(painCave.errMsg, MAX_SIM_ERROR_MSG_LENGTH,
             "The sum of molFractions was not close enough to 1.0");
    painCave.isFatal = 1;
    simError();
  }
 
  int remaining = nSites;
  for (std::size_t i = 0; i < nComponents - 1; i++) {
    nMol.push_back(int((RealType)nSites * molFractions.at(i)));
    remaining -= nMol.at(i);
  }
  nMol.push_back(remaining);
 
  // recompute actual mol fractions and perform final sanity check:
 
  int totalMolecules = 0;
  RealType totalMass = 0.0;
  for (std::size_t i = 0; i < nComponents; i++) {
    molFractions[i] = (RealType)(nMol.at(i)) / (RealType)nSites;
    totalMolecules += nMol.at(i);
    molecularMasses.push_back(MoLocator::getMolMass(
        oldInfo->getMoleculeStamp(i), oldInfo->getForceField()));
    totalMass += (RealType)(nMol.at(i)) * molecularMasses.at(i);
  }
  RealType avgMass = totalMass / (RealType)totalMolecules;
 
  if (totalMolecules != nSites) {
    snprintf(painCave.errMsg, MAX_SIM_ERROR_MSG_LENGTH,
             "Computed total number of molecules is not equal "
             "to the number of lattice sites!");
    painCave.isFatal = 1;
    simError();
  }
 
  latticeConstant = pow(rhoConvertConst * nMolPerCell * avgMass / density,
                        (RealType)(1.0 / 3.0));
 
  // Set the lattice constant
 
  lc.push_back(latticeConstant);
  simpleLat->setLatticeConstant(lc);
 
  // Calculate the lattice sites and fill the lattice vector.
 
  // Get the standard orientations of the cell sites
 
  latticeOrt = simpleLat->getLatticePointsOrt();
 
  vector<Vector3d> sites;
  vector<Vector3d> orientations;
 
  for (int i = 0; i < nx; i++) {
    for (int j = 0; j < ny; j++) {
      for (int k = 0; k < nz; k++) {
        // Get the position of the cell sites
 
        simpleLat->getLatticePointsPos(latticePos, i, j, k);
 
        for (int l = 0; l < nMolPerCell; l++) {
          sites.push_back(latticePos[l]);
          orientations.push_back(latticeOrt[l]);
        }
      }
    }
  }
 
  outputFileName = args_info.output_arg;
 
  // create a new .omd file on the fly which corrects the number of molecules
 
  createMdFile(inputFileName, outputFileName, nMol);
 
  delete oldInfo;
 
  // We need to read in the new SimInfo object, then Parse the
  // md file and set up the system
 
  SimCreator newCreator;
  SimInfo* newInfo = newCreator.createSim(outputFileName, false);
 
  // fill Hmat
 
  hmat(0, 0) = nx * latticeConstant;
  hmat(0, 1) = 0.0;
  hmat(0, 2) = 0.0;
 
  hmat(1, 0) = 0.0;
  hmat(1, 1) = ny * latticeConstant;
  hmat(1, 2) = 0.0;
 
  hmat(2, 0) = 0.0;
  hmat(2, 1) = 0.0;
  hmat(2, 2) = nz * latticeConstant;
 
  // Set Hmat
 
  newInfo->getSnapshotManager()->getCurrentSnapshot()->setHmat(hmat);
 
  // place the molecules
 
  // Randomize a vector of ints:
 
  vector<int> ids;
  for (std::size_t i = 0; i < sites.size(); i++)
    ids.push_back(i);
 
  /* Set up the random number generator engine */
  std::random_device rd;   // Non-deterministic, uniformly-distributed integer
                           // random number generator
  std::mt19937 gen(rd());  // 32-bit Mersenne Twister random number engine
 
  std::shuffle(ids.begin(), ids.end(), gen);
 
  Molecule* mol;
  int l = 0;
  for (std::size_t i = 0; i < nComponents; i++) {
    locator =
        new MoLocator(newInfo->getMoleculeStamp(i), newInfo->getForceField());
    for (int n = 0; n < nMol.at(i); n++) {
      mol = newInfo->getMoleculeByGlobalIndex(l);
      locator->placeMol(sites[ids[l]], orientations[ids[l]], mol);
      l++;
    }
  }
 
  // Create DumpWriter and write out the coordinates
 
  writer = new DumpWriter(newInfo, outputFileName);
 
  if (writer == NULL) {
    snprintf(painCave.errMsg, MAX_SIM_ERROR_MSG_LENGTH,
             "error in creating DumpWriter");
    painCave.isFatal = 1;
    simError();
  }
 
  writer->writeDump();
 
  // deleting the writer will put the closing at the end of the dump file.
 
  delete writer;
 
  snprintf(painCave.errMsg, MAX_SIM_ERROR_MSG_LENGTH,
           "A new OpenMD file called \"%s\" has been "
           "generated.\n",
           outputFileName.c_str());
  painCave.isFatal  = 0;
  painCave.severity = OPENMD_INFO;
  simError();
  return 0;
}
 
void createMdFile(const std::string& oldMdFileName,
                  const std::string& newMdFileName, std::vector<int> nMol) {
  ifstream oldMdFile;
  ofstream newMdFile;
  const int MAXLEN = 65535;
  char buffer[MAXLEN];
 
  // create new .omd file based on old .omd file
 
  oldMdFile.open(oldMdFileName.c_str());
  newMdFile.open(newMdFileName.c_str());
 
  oldMdFile.getline(buffer, MAXLEN);
 
  std::size_t i = 0;
  while (!oldMdFile.eof()) {
    // correct molecule number
    if (strstr(buffer, "nMol") != NULL) {
      if (i < nMol.size()) {
        snprintf(buffer, MAXLEN, "\tnMol = %i;", nMol.at(i));
        newMdFile << buffer << std::endl;
        i++;
      }
    } else
      newMdFile << buffer << std::endl;
 
    oldMdFile.getline(buffer, MAXLEN);
  }
 
  oldMdFile.close();
  newMdFile.close();
 
  if (i != nMol.size()) {
    snprintf(painCave.errMsg, MAX_SIM_ERROR_MSG_LENGTH,
             "Couldn't replace the correct number of nMol\n"
             "\tstatements in component blocks.  Make sure that all\n"
             "\tcomponents in the template file have nMol=1");
    painCave.isFatal = 1;
    simError();
  }
}