include/constr.h

   1 /*
   2  * $Id$
   3  *
   4  *       This source code is part of
   5  *
   6  *        G   R   O   M   A   C   S
   7  *
   8  * GROningen MAchine for Chemical Simulations
   9  *
  10  *               VERSION 2.0
  11  *
  12  * Copyright (c) 1991-1999
  13  * BIOSON Research Institute, Dept. of Biophysical Chemistry
  14  * University of Groningen, The Netherlands
  15  *
  16  * Please refer to:
  17  * GROMACS: A message-passing parallel molecular dynamics implementation
  18  * H.J.C. Berendsen, D. van der Spoel and R. van Drunen
  19  * Comp. Phys. Comm. 91, 43-56 (1995)
  20  *
  21  * Also check out our WWW page:
  22  * http://md.chem.rug.nl/~gmx
  23  * or e-mail to:
  24  * gromacs@chem.rug.nl
  25  *
  26  * And Hey:
  27  * Good ROcking Metal Altar for Chronical Sinners
  28  */
  29 static char *SRCID_constr_h = "$Id$";
  30
  31 extern int bshakef(FILE *log,           /* Log file                     */
  32                    int natoms,          /* Total number of atoms        */
  33                    real invmass[],      /* Atomic masses                */
  34                    int nblocks,         /* The number of shake blocks   */
  35                    int sblock[],        /* The shake blocks             */
  36                    t_idef *idef,        /* The interaction def          */
  37                    t_inputrec *ir,      /* Input record                 */
  38                    matrix box,          /* The box                      */
  39                    rvec x_s[],          /* Coords before update         */
  40                    rvec xp[],           /* Output coords                */
  41                    t_nrnb *nrnb,        /* Performance measure          */
  42                    real *dvdlambda);    /* FEP force                    */
  43 /* Shake all the atoms blockwise. It is assumed that all the constraints
  44  * in the idef->shakes field are sorted, to ascending block nr. The
  45  * sblock array points into the idef->shakes.iatoms field, with block 0
  46  * starting
  47  * at sblock[0] and running to ( < ) sblock[1], block n running from
  48  * sblock[n] to sblock[n+1]. Array sblock should be large enough.
  49  * Return 0 when OK, -1 when shake-error
  50  */
  51 extern void csettle(FILE *log,
  52                     int nshake,         /* Number of water molecules    */
  53                     int owptr[],        /* pointer to Oxygen in b4 & after */
  54                     real b4[],          /* Old coordinates              */
  55                     real after[],       /* New coords, to be settled    */
  56                     real dOH,           /* Constraint length Ox-Hyd     */
  57                     real dHH,           /* Constraint length Hyd-Hyd    */
  58                     real mO,            /* Mass of Oxygen               */
  59                     real mH,            /* Mass of Hydrogen             */
  60                     int *xerror);
  61
  62 extern void cshake(atom_id iatom[],int ncon,int *nnit,int maxnit,
  63                    real dist2[],real xp[],real rij[],real m2[],
  64                    real invmass[],real tt[],int *nerror);
  65 /* Regular iterative shake */
  66
  67 extern void constrain(FILE *log,t_topology *top,t_inputrec *ir,int step,
  68                       t_mdatoms *md,int start,int homenr,
  69                       rvec *x,rvec *xprime,matrix box,
  70                       real lambda,real *dvdlambda,t_nrnb *nrnb);
  71 /* Constrain coordinates xprime using the directions in x,
  72  * init_constraints must have be called once, before calling constrain
  73  */
  74
  75 extern bool init_constraints(FILE *log,t_topology *top,t_inputrec *ir,
  76                              t_mdatoms *md,int start,int homenr);
  77 /* Initialize constraints stuff */
  78
  79 /* C routines for LINCS algorithm */
  80 extern void clincs(rvec *x,rvec *xp,int ncons,
  81                    int *bla1,int *bla2,int *blnr,int *blbnb,real *bllen,
  82                    real *blc,real *blcc,real *blm,
  83                    int nit,int nrec,real *invmass,rvec * r,
  84                    real *vbo,real *vbn,real *vbt,real wangle,int *warn,
  85                    real *lambda);
  86
  87 extern void cconerr(real *max,real *rms,int *imax,rvec *xprime,
  88                     int ncons,int *bla1,int *bla2,real *bllen);
  89
  90 void lincs_warning(rvec *x,rvec *xprime,
  91                    int ncons,int *bla1,int *bla2,real *bllen,real wangle);