/* ----------------------------------------------------------------------
   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.
------------------------------------------------------------------------- */

#ifdef FIX_CLASS

FixStyle(rigid/npt,FixRigidNPT)

#else

#ifndef LMP_FIX_RIGID_NPT_H
#define LMP_FIX_RIGID_NPT_H

#include "fix_rigid.h"

namespace LAMMPS_NS {

class FixRigidNPT : public FixRigid {
 public:
  FixRigidNPT(class LAMMPS *, int, char **);
  ~FixRigidNPT();
  int setmask();
  void init();
  void setup(int);
  void initial_integrate(int);
  void final_integrate();
  double compute_scalar();
  void write_restart(FILE *);
  void restart(char *);
  void reset_target(double);
  
 private:
  int dimension;                      // # of dimensions
  double **conjqm;                    // conjugate quat momentum
  double boltz,nktv2p;
  double t_target,p_target;

  int nf_t,nf_r;                      // trans/rot degrees of freedom
  double *w,*wdti1,*wdti2,*wdti4;     // Yoshida-Suzuki coefficients
  double *q_t,*q_r;                   // trans/rot thermostat mass
  double *eta_t,*eta_r;               // trans/rot thermostat position
  double *eta_dot_t,*eta_dot_r;       // trans/rot thermostat velocity
  double *f_eta_t,*f_eta_r;           // trans/rot thermostat force
  double W, *q_b;                     // baro/thermo masses
  double epsilon,*eta_b;              // baro/thermo positions
  double epsilon_dot,*eta_dot_b;      // baro/thermo velocities
  double f_epsilon,*f_eta_b;          // baro/thermo forces
  double dilation;
  double akin_t,akin_r;
  
  int allremap;                       // remap all atoms
  int kspace_flag;                    // 1 if KSpace invoked, 0 if not
  int nrigidfix;                      // number of rigid fixes
  int *rfix;                          // indicies of rigid fixes
  
  char *id_temp,*id_press;
  class Compute *temperature,*pressure;
  int tcomputeflag,pcomputeflag;
  
  void update_nhcp(double akin_t,double akin_r);
  void update_nhcb();
  void remap();
  inline double maclaurin_series(double);

  void allocate_chain();
  void allocate_order();
  void deallocate_chain();
  void deallocate_order();
};

inline double FixRigidNPT::maclaurin_series(double x)
{
  double x2,x4;
  x2 = x * x;
  x4 = x2 * x2;
  return (1.0 + (1.0/6.0) * x2 + (1.0/120.0) * x4 + (1.0/5040.0) * x2 * x4 +
    (1.0/362880.0) * x4 * x4);
}

}

#endif
#endif