fix_nph_body.cpp

/* ----------------------------------------------------------------------
   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: Trung Dac Nguyen (ndactrung@gmail.com)
------------------------------------------------------------------------- */

#include "fix_nph_body.h"
#include <cstring>
#include <string>
#include "group.h"
#include "modify.h"
#include "error.h"
#include "fmt/format.h"

using namespace LAMMPS_NS;
using namespace FixConst;

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

FixNPHBody::FixNPHBody(LAMMPS *lmp, int narg, char **arg) :
  FixNHBody(lmp, narg, arg)
{
  if (tstat_flag)
    error->all(FLERR,"Temperature control can not be used with fix nph/body");
  if (!pstat_flag)
    error->all(FLERR,"Pressure control must be used with fix nph/body");

  // create a new compute temp style
  // id = fix-ID + temp
  // compute group = all since pressure is always global (group all)
  // and thus its KE/temperature contribution should use group all

  std::string tcmd = id + std::string("_temp");
  id_temp = new char[tcmd.size()+1];
  strcpy(id_temp,tcmd.c_str());

  tcmd += fmt::format(" {} temp/body",group->names[igroup]);
  modify->add_compute(tcmd);
  tcomputeflag = 1;

  // create a new compute pressure style
  // id = fix-ID + press, compute group = all
  // pass id_temp as 4th arg to pressure constructor

  std::string pcmd = id + std::string("_press");
  id_press = new char[pcmd.size()+1];
  strcpy(id_press,pcmd.c_str());

  modify->add_compute(pcmd + " all pressure " + std::string(id_temp));
  pcomputeflag = 1;
}