/*************************************************************************/ /* */ /* Copyright (c) 1994 Stanford University */ /* */ /* All rights reserved. */ /* */ /* Permission is given to use, copy, and modify this software for any */ /* non-commercial purpose as long as this copyright notice is not */ /* removed. All other uses, including redistribution in whole or in */ /* part, are forbidden without prior written permission. */ /* */ /* This software is provided with absolutely no warranty and no */ /* support. */ /* */ /*************************************************************************/ EXTERN_ENV #include "mdvar.h" #include "frcnst.h" #include "water.h" #include "wwpot.h" #include #include "parameters.h" #include "mddata.h" #include "split.h" #include "global.h" void POTENG(double *POTA, double *POTR, double *PTRF, long ProcID) { /* this routine calculates the potential energy of the system. it is only called at periods specified by the user, typically in those time-steps when the user wants to print output. FC11 ,FC12, FC13, and FC33 are the quardratic force constants */ long KC, K; long XBOX, YBOX, ZBOX; long X_NUM, Y_NUM, Z_NUM; long i, j, k; double R1, R2, RX, COS, DT, DR1, DR2, DR1S, DR2S, DRP; double XL[15], YL[15], ZL[15], RS[15], RL[15]; double DTS; double LPOTA, LPOTR, LPTRF; struct link *curr_ptr, *neighbor_ptr; struct list_of_boxes *curr_box; double *tx_p, *ty_p, *tz_p; double tempa, tempb, tempc; /* compute intra-molecular potential energy */ LPOTA=0.0; 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 */ /* Go through the molecules in a box */ curr_ptr = BOX[i][j][k].list; while (curr_ptr) { tx_p = curr_ptr->mol.F[DISP][XDIR]; ty_p = curr_ptr->mol.F[DISP][YDIR]; tz_p = curr_ptr->mol.F[DISP][ZDIR]; curr_ptr->mol.VM[XDIR] = C1 * tx_p[O] + C2 * (tx_p[H1] + tx_p[H2]); curr_ptr->mol.VM[YDIR] = C1*ty_p[O] + C2*(ty_p[H1] + ty_p[H2]); curr_ptr->mol.VM[ZDIR] = C1*tz_p[O] + C2*(tz_p[H1] + tz_p[H2]); tempa = tx_p[O] - tx_p[H1]; tempb = ty_p[O] - ty_p[H1]; tempc = tz_p[O] - tz_p[H1]; R1 = tempa * tempa + tempb * tempb + tempc * tempc; tempa = tx_p[O] - tx_p[H2]; tempb = ty_p[O] - ty_p[H2]; tempc = tz_p[O] - tz_p[H2]; R2 = tempa * tempa + tempb * tempb + tempc * tempc; RX = ((tx_p[O] - tx_p[H1]) * (tx_p[O] - tx_p[H2])) + ((ty_p[O] - ty_p[H1]) * (ty_p[O] - ty_p[H2])) + ((tz_p[O] - tz_p[H1]) * (tz_p[O] - tz_p[H2])); R1=sqrt(R1); R2=sqrt(R2); COS=RX/(R1*R2); DT=(acos(COS)-ANGLE)*ROH; DR1=R1-ROH; DR2=R2-ROH; DR1S=DR1*DR1; DR2S=DR2*DR2; DRP=DR1+DR2; DTS=DT*DT; LPOTA += (FC11*(DR1S+DR2S)+FC33*DTS)*0.5 +FC12*DR1*DR2+FC13*DRP*DT +(FC111*(DR1S*DR1+DR2S*DR2)+FC333*DTS*DT+FC112*DRP*DR1*DR2+ FC113*(DR1S+DR2S)*DT+FC123*DR1*DR2*DT+FC133*DRP*DTS)*ROHI; LPOTA += (FC1111*(DR1S*DR1S+DR2S*DR2S)+FC3333*DTS*DTS+ FC1112*(DR1S+DR2S)*DR1*DR2+FC1122*DR1S*DR2S+ FC1113*(DR1S*DR1+DR2S*DR2)*DT+FC1123*DRP*DR1*DR2*DT+ FC1133*(DR1S+DR2S)*DTS+FC1233*DR1*DR2*DTS+ FC1333*DRP*DTS*DT)*ROHI2; curr_ptr = curr_ptr->next_mol; } /* while curr_ptr */ curr_box = curr_box->next_box; } /* while curr_box */ BARRIER(gl->PotengBar, NumProcs); /* compute inter-molecular potential energy */ LPOTR=0.0; LPTRF=0.0; 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++) { X_NUM = XBOX; Y_NUM = YBOX; Z_NUM = ZBOX; if ((BOX_PER_SIDE == 2) && ((XBOX < 0) || (XBOX == 2) || (YBOX < 0) || (YBOX == 2) || (ZBOX < 0) || (ZBOX == 2))) continue; /* 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 */ 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 < 9; K++) { if (RS[K] <= CUT2) { RL[K]=sqrt(RS[K]); } else { RL[K]=CUTOFF; RS[K]=CUT2; } /* else */ } /* for K */ LPOTR= LPOTR-QQ2/RL[1]-QQ2/RL[2]-QQ2/RL[3]-QQ2/RL[4] + QQ/RL[5]+ QQ/RL[6]+ QQ/RL[7]+ QQ/RL[8] + QQ4/RL[0]; LPTRF= LPTRF-REF2*RS[0]-REF1*((RS[5]+RS[6]+RS[7]+RS[8])*0.5 -RS[1]-RS[2]-RS[3]-RS[4]); if (KC <= 0) { for (K = 9; K < 14; K++) { RL[K]=sqrt(XL[K]*XL[K]+YL[K]*YL[K]+ZL[K]*ZL[K]); } LPOTR= LPOTR+A1* exp(-B1*RL[9]) +A2*(exp(-B2*RL[ 5])+exp(-B2*RL[ 6]) +exp(-B2*RL[ 7])+exp(-B2*RL[ 8])) +A3*(exp(-B3*RL[10])+exp(-B3*RL[11]) +exp(-B3*RL[12])+exp(-B3*RL[13])) -A4*(exp(-B4*RL[10])+exp(-B4*RL[11]) +exp(-B4*RL[12])+exp(-B4*RL[13])); } /* if KC <= 0 */ } /* if KC != 9 */ curr_ptr = curr_ptr->next_mol; } neighbor_ptr = neighbor_ptr->next_mol; } } } } /* neighbor boxes for loops */ curr_box = curr_box->next_box; } /* while curr_box */ LPOTR = LPOTR/2.0; LPTRF = LPTRF/2.0; /* update shared sums from computed private sums */ LOCK(gl->PotengSumLock); *POTA = *POTA + LPOTA; *POTR = *POTR + LPOTR; *PTRF = *PTRF + LPTRF; UNLOCK(gl->PotengSumLock); } /* end of subroutine POTENG */