/*
 * $Id: vcm.h,v 1.15 2003/11/17 21:50:43 spoel Exp $
 * 
 *                This source code is part of
 * 
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 *          GROningen MAchine for Chemical Simulations
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 *                        VERSION 3.2.0
 * Written by David van der Spoel, Erik Lindahl, Berk Hess, and others.
 * Copyright (c) 1991-2000, University of Groningen, The Netherlands.
 * Copyright (c) 2001-2004, The GROMACS development team,
 * check out http://www.gromacs.org for more information.

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#ifndef _vcm_h
#define _vcm_h

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include "sysstuff.h"
#include "typedefs.h"

typedef struct {
  int    nr;                   /* Number of groups                    */
  int    mode;                 /* One of the enums above              */
  rvec   *group_p;             /* Linear momentum per group           */
  rvec   *group_v;             /* Linear velocity per group           */
  rvec   *group_x;             /* Center of mass per group            */
  rvec   *group_j;             /* Angular momentum per group          */
  rvec   *group_w;             /* Angular velocity (omega)            */
  tensor *group_i;             /* Moment of inertia per group         */
  real   *group_mass;          /* Mass per group                      */
  char   **group_name;         /* These two are copies to pointers in */
  unsigned short *group_id;    /* other structures.                   */
} t_vcm;

t_vcm *init_vcm(FILE *fp,t_topology *top,t_commrec *cr,t_mdatoms *md,
		int start,int homenr,int nstcomm);

/* Do a per group center of mass things */
extern void calc_vcm_grp(FILE *fp,int start,int homenr,real mass[],
			 rvec x[],rvec v[],t_vcm *vcm);

extern void do_stopcm_grp(FILE *fp,int start,int homenr,
			  rvec x[],rvec v[],t_vcm *vcm);

extern void check_cm_grp(FILE *fp,t_vcm *vcm);
			 
#endif /* _vcm_h */
