EXTERN_ENV
#include <stdio.h>
#include <math.h>
#include "mdvar.h"
#include "water.h"
#include "wwpot.h"
#include "cnst.h"
#include "parameters.h"
#include "mddata.h"
#include "split.h"
#include "global.h"
void INTERF(long DEST, double *VIR, long ProcID)
{
/* This is the routine that computes intermolecular interactions and
* hence takes up most of the execution time. It is
* called both from main() and from mdmain().
* When called from main(), it is used to estimate the initial
* accelerations by computing intermolecular forces. When called
* from mdmain(), it is used to compute intermolecular forces.
* The parameter DEST specifies whether results go into the
* accelerations or the forces. It uses the routine UPDATE_FORCES
* which is defined in this file, and routine CSHIFT in file cshift.U
*
* This routine calculates inter-molecular interaction forces.
* the distances are arranged in the order M-M, M-H1, M-H2, H1-M,
* H2-M, H1-H2, H1-H1, H2-H1, H2-H2, O-O, O-H1, O-H2, H1-O, H2-O,
* where the M are "centers" of the molecules.
*/
long dir;
long KC, K;
long i, j, k;
long XBOX, YBOX, ZBOX, X_NUM, Y_NUM, Z_NUM;
/* per interaction arrays that hold some computed distances */
double YL[15], XL[15], ZL[15], RS[15], FF[15], RL[15];
double FTEMP;
double LVIR = 0.0;
struct link *curr_ptr, *neighbor_ptr;
struct list_of_boxes *curr_box;
double *temp_p;
curr_box = my_boxes[ProcID];
while (curr_box) {
i = curr_box->coord[XDIR]; /* X coordinate of box */
j = curr_box->coord[YDIR]; /* Y coordinate of box */
k = curr_box->coord[ZDIR]; /* Z coordinate of box */
/* loop over nearest neighbor boxes */
for (XBOX=i-1; XBOX<=i+1; XBOX++) {
for (YBOX=j-1; YBOX<=j+1; YBOX++) {
for (ZBOX=k-1; ZBOX<=k+1; ZBOX++) {
/* Special case for two boxes per side */
if ((BOX_PER_SIDE == 2) && ((XBOX < 0) || (XBOX == 2) ||
(YBOX < 0) || (YBOX == 2) || (ZBOX < 0) || (ZBOX == 2)))
continue;
X_NUM = XBOX;
Y_NUM = YBOX;
Z_NUM = ZBOX;
/* Make box number valid if out of box */
if (X_NUM == -1)
X_NUM += BOX_PER_SIDE;
else if (X_NUM >= BOX_PER_SIDE)
X_NUM -= BOX_PER_SIDE;
if (Y_NUM == -1)
Y_NUM += BOX_PER_SIDE;
else if (Y_NUM >= BOX_PER_SIDE)
Y_NUM -= BOX_PER_SIDE;
if (Z_NUM == -1)
Z_NUM += BOX_PER_SIDE;
else if (Z_NUM >= BOX_PER_SIDE)
Z_NUM -= BOX_PER_SIDE;
/* Don't do current box more than once */
if ((X_NUM == i) && (Y_NUM == j) && (Z_NUM == k) &&
((XBOX != i) || (YBOX != j) || (ZBOX !=k))) {
continue;
}
neighbor_ptr = BOX[X_NUM][Y_NUM][Z_NUM].list;
while (neighbor_ptr) {
/* go through current box list */
curr_ptr = BOX[i][j][k].list;
while (curr_ptr) {
/* Don't do interaction with same molecule */
if (curr_ptr == neighbor_ptr) {
curr_ptr = curr_ptr->next_mol;
continue;
}
/* compute some intermolecular distances;
first call CSHIFT to implement periodic boundary conditions */
CSHIFT(curr_ptr->mol.F[DISP][XDIR],neighbor_ptr->mol.F[DISP][XDIR],
curr_ptr->mol.VM[XDIR],neighbor_ptr->mol.VM[XDIR],XL,BOXH,BOXL);
CSHIFT(curr_ptr->mol.F[DISP][YDIR],neighbor_ptr->mol.F[DISP][YDIR],
curr_ptr->mol.VM[YDIR],neighbor_ptr->mol.VM[YDIR],YL,BOXH,BOXL);
CSHIFT(curr_ptr->mol.F[DISP][ZDIR],neighbor_ptr->mol.F[DISP][ZDIR],
curr_ptr->mol.VM[ZDIR],neighbor_ptr->mol.VM[ZDIR],ZL,BOXH,BOXL);
KC=0;
for (K = 0; K < 9; K++) {
RS[K]=XL[K]*XL[K]+YL[K]*YL[K]+ZL[K]*ZL[K];
if (RS[K] > CUT2)
KC++;
} /* for K */
if (KC != 9) {
for (K = 0; K < 14; K++)
FF[K]=0.0;
if (RS[0] < CUT2) {
FF[0]=QQ4/(RS[0]*sqrt(RS[0]))+REF4;
LVIR = LVIR + FF[0]*RS[0];
} /* if */
for (K = 1; K < 5; K++) {
if (RS[K] < CUT2) {
FF[K]= -QQ2/(RS[K]*sqrt(RS[K]))-REF2;
LVIR = LVIR + FF[K]*RS[K];
} /* if */
if (RS[K+4] <= CUT2) {
RL[K+4]=sqrt(RS[K+4]);
FF[K+4]=QQ/(RS[K+4]*RL[K+4])+REF1;
LVIR = LVIR + FF[K+4]*RS[K+4];
} /* if */
} /* for K */
if (KC == 0) {
RS[9]=XL[9]*XL[9]+YL[9]*YL[9]+ZL[9]*ZL[9];
RL[9]=sqrt(RS[9]);
FF[9]=AB1*exp(-B1*RL[9])/RL[9];
LVIR = LVIR + FF[9]*RS[9];
for (K = 10; K < 14; K++) {
FTEMP=AB2*exp(-B2*RL[K-5])/RL[K-5];
FF[K-5]=FF[K-5]+FTEMP;
LVIR= LVIR+FTEMP*RS[K-5];
RS[K]=XL[K]*XL[K]+YL[K]*YL[K]+ZL[K]*ZL[K];
RL[K]=sqrt(RS[K]);
FF[K]=(AB3*exp(-B3*RL[K])-AB4*exp(-B4*RL[K]))/RL[K];
LVIR = LVIR + FF[K]*RS[K];
} /* for K */
} /* if KC == 0 */
UPDATE_FORCES(curr_ptr, DEST, XL, YL, ZL, FF);
} /* if KC != 9 */
curr_ptr = curr_ptr->next_mol;
} /* while curr_ptr */
neighbor_ptr = neighbor_ptr->next_mol;
} /* while neighbor_ptr */
}
}
} /* neighbor boxes' for loops */
curr_box = curr_box->next_box;
} /* while mybox */
/* accumulate running sum from private partial sums */
LOCK(gl->InterfVirLock);
*VIR = *VIR + LVIR/2.0;
UNLOCK(gl->InterfVirLock);
/* wait till all forces are updated */
BARRIER(gl->InterfBar, NumProcs);
/* divide final forces by masses */
curr_box = my_boxes[ProcID];
while (curr_box) {
i = curr_box->coord[XDIR]; /* X coordinate of box */
j = curr_box->coord[YDIR]; /* Y coordinate of box */
k = curr_box->coord[ZDIR]; /* Z coordinate of box */
curr_ptr = BOX[i][j][k].list;
while (curr_ptr) {
for ( dir = XDIR; dir <= ZDIR; dir++) {
temp_p = curr_ptr->mol.F[DEST][dir];
temp_p[H1] = temp_p[H1] * FHM;
temp_p[O] = temp_p[O] * FOM;
temp_p[H2] = temp_p[H2] * FHM;
} /* for dir */
curr_ptr = curr_ptr->next_mol;
} /* while curr_ptr */
curr_box = curr_box->next_box;
} /* while curr_box */
}/* end of subroutine INTERF */
void INTERF(long DEST, double *VIR, long ProcID)
{
/* This routine gets called both from main() and from mdmain().
When called from main(), it is used to estimate the initial
accelerations by computing intermolecular forces. When called
from mdmain(), it is used to compute intermolecular forces.
The parameter DEST specifies whether results go into the
accelerations or the forces. Uses routine UPDATE_FORCES in this
file, and routine CSHIFT in file cshift.U */
/*
.....this routine calculates inter-molecular interaction forces
the distances are arranged in the order M-M, M-H1, M-H3, H1-M,
H3-M, H1-H3, H1-H1, H3-H1, H3-H3, O-O, O-H1, O-H3, H1-O, H3-O,
where the M are "centers" of the molecules.
*/
long mol, comp, dir, icomp;
long comp_last, half_mol;
long KC, K;
double YL[15], XL[15], ZL[15], RS[15], FF[15], RL[15]; /* per-
interaction arrays that hold some computed distances */
double FTEMP;
double LVIR = 0.0;
double *temp_p;
{ /* initialize PFORCES array */
long ct1,ct2,ct3;
for (ct1 = 0; ct1<NMOL; ct1++)
for (ct2 = 0; ct2<NDIR; ct2++)
for (ct3 = 0; ct3<NATOM; ct3++)
PFORCES[ProcID][ct1][ct2][ct3] = 0;
}
half_mol = NMOL/2;
for (mol = StartMol[ProcID]; mol < StartMol[ProcID+1]; mol++) {
comp_last = mol + half_mol;
if (NMOL%2 == 0) {
if ((half_mol <= mol) && (mol%2 == 0)) {
comp_last--;
}
if ((mol < half_mol) && (comp_last%2 == 1)) {
comp_last--;
}
}
for (icomp = mol+1; icomp <= comp_last; icomp++) {
comp = icomp;
if (comp > NMOL1) comp = comp%NMOL;
/* compute some intermolecular distances */
CSHIFT(VAR[mol].F[DISP][XDIR],VAR[comp].F[DISP][XDIR],
VAR[mol].VM[XDIR],VAR[comp].VM[XDIR],XL,BOXH,BOXL);
CSHIFT(VAR[mol].F[DISP][YDIR],VAR[comp].F[DISP][YDIR],
VAR[mol].VM[YDIR],VAR[comp].VM[YDIR],YL,BOXH,BOXL);
CSHIFT(VAR[mol].F[DISP][ZDIR],VAR[comp].F[DISP][ZDIR],
VAR[mol].VM[ZDIR],VAR[comp].VM[ZDIR],ZL,BOXH,BOXL);
KC=0;
for (K = 0; K < 9; K++) {
RS[K]=XL[K]*XL[K]+YL[K]*YL[K]+ZL[K]*ZL[K];
if (RS[K] > CUT2)
KC++;
} /* for K */
if (KC != 9) {
for (K = 0; K < 14; K++)
FF[K]=0.0;
if (RS[0] < CUT2) {
FF[0]=QQ4/(RS[0]*sqrt(RS[0]))+REF4;
LVIR = LVIR + FF[0]*RS[0];
} /* if */
for (K = 1; K < 5; K++) {
if (RS[K] < CUT2) {
FF[K]= -QQ2/(RS[K]*sqrt(RS[K]))-REF2;
LVIR = LVIR + FF[K]*RS[K];
} /* if */
if (RS[K+4] <= CUT2) {
RL[K+4]=sqrt(RS[K+4]);
FF[K+4]=QQ/(RS[K+4]*RL[K+4])+REF1;
LVIR = LVIR + FF[K+4]*RS[K+4];
} /* if */
} /* for K */
if (KC == 0) {
RS[9]=XL[9]*XL[9]+YL[9]*YL[9]+ZL[9]*ZL[9];
RL[9]=sqrt(RS[9]);
FF[9]=AB1*exp(-B1*RL[9])/RL[9];
LVIR = LVIR + FF[9]*RS[9];
for (K = 10; K < 14; K++) {
FTEMP=AB2*exp(-B2*RL[K-5])/RL[K-5];
FF[K-5]=FF[K-5]+FTEMP;
LVIR= LVIR+FTEMP*RS[K-5];
RS[K]=XL[K]*XL[K]+YL[K]*YL[K]+ZL[K]*ZL[K];
RL[K]=sqrt(RS[K]);
FF[K]=(AB3*exp(-B3*RL[K])-AB4*exp(-B4*RL[K]))/RL[K];
LVIR = LVIR + FF[K]*RS[K];
} /* for K */
} /* if KC == 0 */
UPDATE_FORCES(mol, comp, XL, YL, ZL, FF, ProcID);
} /* if KC != 9 */
} /* for comp */
} /* for mol */
/* accumulate the running sum from private
per-interaction partial sums */
LOCK(gl->InterfVirLock);
*VIR = *VIR + LVIR;
UNLOCK(gl->InterfVirLock);
/* at the end of the above force-computation, comp_last */
/* contains the number of the last molecule (no modulo) */
/* that this process touched */
if (comp_last > NMOL1) {
for (mol = StartMol[ProcID]; mol < NMOL; mol++) {
ALOCK(gl->MolLock, mol % MAXLCKS);
for ( dir = XDIR; dir <= ZDIR; dir++) {
temp_p = VAR[mol].F[DEST][dir];
temp_p[H1] += PFORCES[ProcID][mol][dir][H1];
temp_p[O] += PFORCES[ProcID][mol][dir][O];
temp_p[H2] += PFORCES[ProcID][mol][dir][H2];
}
AULOCK(gl->MolLock, mol % MAXLCKS);
}
comp = comp_last % NMOL;
for (mol = 0; ((mol <= comp) && (mol < StartMol[ProcID])); mol++) {
ALOCK(gl->MolLock, mol % MAXLCKS);
for ( dir = XDIR; dir <= ZDIR; dir++) {
temp_p = VAR[mol].F[DEST][dir];
temp_p[H1] += PFORCES[ProcID][mol][dir][H1];
temp_p[O] += PFORCES[ProcID][mol][dir][O];
temp_p[H2] += PFORCES[ProcID][mol][dir][H2];
}
AULOCK(gl->MolLock, mol % MAXLCKS);
}
}
else{
for (mol = StartMol[ProcID]; mol <= comp_last; mol++) {
ALOCK(gl->MolLock, mol % MAXLCKS);
for ( dir = XDIR; dir <= ZDIR; dir++) {
temp_p = VAR[mol].F[DEST][dir];
temp_p[H1] += PFORCES[ProcID][mol][dir][H1];
temp_p[O] += PFORCES[ProcID][mol][dir][O];
temp_p[H2] += PFORCES[ProcID][mol][dir][H2];
}
AULOCK(gl->MolLock, mol % MAXLCKS);
}
}
/* wait till all forces are updated */
BARRIER(gl->InterfBar, NumProcs);
/* divide final forces by masses */
for (mol = StartMol[ProcID]; mol < StartMol[ProcID+1]; mol++) {
for ( dir = XDIR; dir <= ZDIR; dir++) {
temp_p = VAR[mol].F[DEST][dir];
temp_p[H1] = temp_p[H1] * FHM;
temp_p[O] = temp_p[O] * FOM;
temp_p[H2] = temp_p[H2] * FHM;
} /* for dir */
} /* for mol */
}/* end of subroutine INTERF */