|
allen-tildesley-book
|
|
README,
f.00,
f.01,
f.02,
f.03,
f.04,
f.05,
f.06,
f.07,
f.08,
f.09,
f.10,
f.11,
f.12,
f.13,
f.14,
f.15,
f.16,
f.17,
f.18,
f.19,
f.20,
f.21,
f.22,
f.23,
f.24,
f.25,
f.26,
f.27,
f.28,
f.29,
f.30,
f.31,
f.32,
f.33,
f.34,
f.35,
f.36,
f.37,
older-version
|
|
|
********************************************************************************
** FICHE F.6. LEAPFROG ALGORITHMS FOR ROTATIONAL MOTION **
** This FORTRAN code is intended to illustrate points made in the text. **
** To our knowledge it works correctly. However it is the responsibility of **
** the user to test it, if it is to be used in a research application. **
********************************************************************************
C *******************************************************************
C ** TWO SEPARATE PARTS: ROTATION OF LINEAR, NONLINEAR MOLECULES. **
C *******************************************************************
C *******************************************************************
C ** FICHE F.6 - PART A **
C ** LEAPFROG ALGORITHM FOR ROTATIONAL MOTION OF LINEAR MOLECULES. **
C ** **
C ** REFERENCE: **
C ** **
C ** FINCHAM, CCP5 QUARTERLY 2, 6, 1981. **
C ** **
C ** SUPPLIED ROUTINES: **
C ** **
C ** SUBROUTINE MOVE ( DT, M, INERT, K ) **
C ** ADVANCES POSITIONS AND VELOCITIES **
C ** SUBROUTINE MOLATM **
C ** CONVERTS MOLECULAR COORDINATES TO ATOMIC/SITE POSITIONS **
C ** SUBROUTINE ATMMOL **
C ** CONVERTS ATOMIC FORCES TO MOLECULAR FORCES AND "TORQUES" **
C ** **
C ** PRINCIPAL VARIABLES: **
C ** **
C ** REAL DT TIMESTEP **
C ** INTEGER N NUMBER OF MOLECULES **
C ** INTEGER NA NUMBER OF ATOMS PER MOL **
C ** REAL M MOLECULAR MASS **
C ** REAL INERT MOMENT OF INERTIA **
C ** REAL K KINETIC ENERGY **
C ** REAL RX(N),RY(N),RZ(N) POSITIONS AT TIME T **
C ** REAL VX(N),VY(N),VZ(N) VELOCITIES AT TIME T **
C ** REAL FX(N),FY(N),FZ(N) C-O-M FORCES **
C ** REAL EX(N),EY(N),EZ(N) UNIT BOND VEC AT TIME T **
C ** REAL UX(N),UY(N),UZ(N) TIME DERIV AT T-DT/2 **
C ** REAL GX(N),GY(N),GZ(N) AUXILIARY TORQUE AT T **
C ** **
C ** USAGE: **
C ** **
C ** SUBROUTINE MOLATM IS CALLED, TO OBTAIN ATOMIC SITE POSITIONS **
C ** WHICH ARE USED BY THE FORCE ROUTINE (NOT SUPPLIED HERE) TO **
C ** CALCULATE ATOMIC FORCES. SUBROUTINE ATMMOL THEN CONVERTS **
C ** THESE INTO MOLECULAR FORCE AND MODIFIED TORQUE TERMS. **
C ** SUBROUTINE MOVE THEN ADVANCES THE POSITIONS ETC. **
C ** FOR THIS EXAMPLE WE TAKE A (LINEAR) TRIATOMIC MOLECULE. **
C *******************************************************************
SUBROUTINE MOVE ( DT, M, INERT, K )
COMMON / BLOCK1 / RX, RY, RZ, VX, VY, VZ, FX, FY, FZ
COMMON / BLOCK2 / EX, EY, EZ, UX, UY, UZ, GX, GY, GZ
C *******************************************************************
C ** ADVANCES POSITIONS, BOND VECTORS, AND THEIR TIME DERIVATIVES. **
C ** **
C ** THIS METHOD USES AN AUXILIARY VECTOR TO DESCRIBE THE TORQUE **
C ** AND THE BOND VECTOR DERIVATIVE INSTEAD OF ANGULAR VELOCITY. **
C ** EVERYTHING IS IN SPACE-FIXED AXES. **
C *******************************************************************
INTEGER N
PARAMETER ( N = 108 )
INTEGER NA
PARAMETER ( NA = 3 )
REAL DT
REAL M
REAL INERT, K
REAL RX(N), RY(N), RZ(N)
REAL VX(N), VY(N), VZ(N)
REAL FX(N), FY(N), FZ(N)
REAL EX(N), EY(N), EZ(N)
REAL UX(N), UY(N), UZ(N)
REAL GX(N), GY(N), GZ(N)
INTEGER I
REAL UXI, UYI, UZI, EXI, EYI, EZI, VXI, VYI, VZI, DOT
C *******************************************************************
K = 0.0
DO 400 I = 1, N
C ** MOVE BOND VECTOR DERIVATIVES **
C ** FROM T-DT/2 TO T+DT/2 AND STORE AWAY **
UXI = UX(I)
UYI = UY(I)
UZI = UZ(I)
EXI = EX(I)
EYI = EY(I)
EZI = EZ(I)
DOT = 2.0 * ( UXI * EXI + UYI * EYI + UZI * EZI )
UX(I) = UXI + DT * GX(I) / INERT - DOT * EXI
UY(I) = UYI + DT * GY(I) / INERT - DOT * EYI
UZ(I) = UZI + DT * GZ(I) / INERT - DOT * EZI
UXI = 0.5 * ( UXI + UX(I) )
UYI = 0.5 * ( UYI + UY(I) )
UZI = 0.5 * ( UZI + UZ(I) )
K = K + INERT * ( UXI ** 2 + UYI ** 2 + UZI ** 2 )
C ** ADVANCE BOND VECTORS TO T+DT **
EX(I) = EXI + DT * UX(I)
EY(I) = EYI + DT * UY(I)
EZ(I) = EZI + DT * UZ(I)
C ** MOVE THE LINEAR VELOCITIES ALL THE WAY **
C ** FROM T-DT/2 TO T+DT/2 AND STORE AWAY **
VXI = VX(I)
VYI = VY(I)
VZI = VZ(I)
VX(I) = VXI + DT * FX(I) / M
VY(I) = VYI + DT * FY(I) / M
VZ(I) = VZI + DT * FZ(I) / M
VXI = 0.5 * ( VXI + VX(I) )
VYI = 0.5 * ( VYI + VY(I) )
VZI = 0.5 * ( VZI + VZ(I) )
K = K + M * ( VXI **2 + VYI ** 2 + VZI ** 2 )
C ** ADVANCE POSITIONS TO T+DT **
RX(I) = RX(I) + DT * VX(I)
RY(I) = RY(I) + DT * VY(I)
RZ(I) = RZ(I) + DT * VZ(I)
400 CONTINUE
K = 0.5 * K
RETURN
END
SUBROUTINE MOLATM
COMMON / BLOCK1 / RX, RY, RZ, VX, VY, VZ, FX, FY, FZ
COMMON / BLOCK2 / EX, EY, EZ, UX, UY, UZ, GX, GY, GZ
COMMON / BLOCK3 / D, RSX, RSY, RSZ, FSX, FSY, FSZ
C *******************************************************************
C ** CONVERTS C-O-M COORDINATES AND BOND VECTOR TO SITE POSITIONS. **
C ** **
C ** THE POSITION OF EACH ATOM IN THE MOLECULE IS DEFINED IN TERMS **
C ** OF THE UNIT BOND VECTOR EX(I),EY(I),EZ(I) AND THE ATOM **
C ** POSITION VARIABLE D(A): RSX(I,A) = RX(I) + D(A)*EX(I) ETC. **
C ** **
C ** PRINCIPAL VARIABLES: **
C ** **
C ** INTEGER N NUMBER OF MOLECULES **
C ** INTEGER NA NUMBER OF ATOMS PER MOL **
C ** REAL RX(N),RY(N),RZ(N) POSITIONS AT TIME T **
C ** REAL EX(N),EY(N),EZ(N) UNIT BOND VEC AT TIME T **
C ** REAL D(NA) ATOM POSITIONS IN MOLEC **
C ** REAL RSX(N,NA),RSY(N,NA),RSZ(N,NA) ATOM POSITIONS **
C *******************************************************************
INTEGER N
PARAMETER ( N = 108 )
INTEGER NA
PARAMETER ( NA = 3 )
REAL RX(N), RY(N), RZ(N)
REAL VX(N), VY(N), VZ(N)
REAL FX(N), FY(N), FZ(N)
REAL EX(N), EY(N), EZ(N)
REAL UX(N), UY(N), UZ(N)
REAL GX(N), GY(N), GZ(N)
REAL D(NA)
REAL RSX(N,NA), RSY(N,NA), RSZ(N,NA)
REAL FSX(N,NA), FSY(N,NA), FSZ(N,NA)
INTEGER I, A
REAL EXI, EYI, EZI
C *******************************************************************
DO 200 I = 1, N
EXI = EX(I)
EYI = EY(I)
EZI = EZ(I)
DO 199 A = 1, NA
RSX(I,A) = RX(I) + D(A) * EXI
RSY(I,A) = RY(I) + D(A) * EYI
RSZ(I,A) = RZ(I) + D(A) * EZI
199 CONTINUE
200 CONTINUE
RETURN
END
SUBROUTINE ATMMOL
COMMON / BLOCK1 / RX, RY, RZ, VX, VY, VZ, FX, FY, FZ
COMMON / BLOCK2 / EX, EY, EZ, UX, UY, UZ, GX, GY, GZ
COMMON / BLOCK3 / D, RSX, RSY, RSZ, FSX, FSY, FSZ
C *******************************************************************
C ** CONVERT ATOM FORCES TO TOTAL FORCES AND AUXILIARY TORQUES. **
C ** **
C ** PRINCIPAL VARIABLES: **
C ** **
C ** INTEGER N NUMBER OF MOLECULES **
C ** INTEGER NA NUMBER OF ATOMS PER MOL **
C ** REAL RX(N),RY(N),RZ(N) POSITIONS AT TIME T **
C ** REAL FX(N),FY(N),FZ(N) C-O-M FORCES **
C ** REAL EX(N),EY(N),EZ(N) UNIT BOND VEC AT TIME T **
C ** REAL GX(N),GY(N),GZ(N) AUXILIARY TORQUE AT T **
C ** REAL D(NA) ATOM POSITIONS IN MOLEC **
C ** REAL RSX(N,NA),RSY(N,NA),RSZ(N,NA) ATOM POSITIONS **
C ** REAL FSX(N,NA),FSY(N,NA),FSZ(N,NA) FORCES ON EACH ATOM **
C *******************************************************************
INTEGER N
PARAMETER ( N = 108 )
INTEGER NA
PARAMETER ( NA = 3 )
REAL RX(N), RY(N), RZ(N)
REAL VX(N), VY(N), VZ(N)
REAL FX(N), FY(N), FZ(N)
REAL EX(N), EY(N), EZ(N)
REAL UX(N), UY(N), UZ(N)
REAL GX(N), GY(N), GZ(N)
REAL D(NA)
REAL RSX(N,NA), RSY(N,NA), RSZ(N,NA)
REAL FSX(N,NA), FSY(N,NA), FSZ(N,NA)
INTEGER I, A
REAL FXI, FYI, FZI, GXI, GYI, GZI
REAL RXI, RYI, RZI, EXI, EYI, EZI
REAL FSXIA, FSYIA, FSZIA, DOT
C *******************************************************************
DO 300 I = 1, N
FXI = 0.0
FYI = 0.0
FZI = 0.0
GXI = 0.0
GYI = 0.0
GZI = 0.0
RXI = RX(I)
RYI = RY(I)
RZI = RZ(I)
EXI = EX(I)
EYI = EY(I)
EZI = EZ(I)
DO 299 A = 1, NA
FSXIA = FSX(I,A)
FSYIA = FSY(I,A)
FSZIA = FSZ(I,A)
FXI = FXI + FSXIA
FYI = FYI + FSYIA
FZI = FZI + FSZIA
GXI = GXI + D(A) * FSXIA
GYI = GYI + D(A) * FSYIA
GZI = GZI + D(A) * FSZIA
299 CONTINUE
FX(I) = FXI
FY(I) = FYI
FZ(I) = FZI
DOT = GXI * EXI + GYI * EYI + GZI * EZI
GX(I) = GXI - DOT * EXI
GY(I) = GYI - DOT * EYI
GZ(I) = GZI - DOT * EZI
300 CONTINUE
RETURN
END
C *******************************************************************
C ** FICHE F.6 - PART B **
C ** LEAPFROG ALGORITHM FOR ROTATIONAL MOTION, NONLINEAR MOLECULES.**
C ** **
C ** REFERENCE: **
C ** **
C ** FINCHAM, CCP5 QUARTERLY 12, 47, 1984. **
C ** **
C ** SUPPLIED ROUTINES: **
C ** **
C ** SUBROUTINE MOVE ( DT, M, IXX, IYY, IZZ, K ) **
C ** ADVANCES POSITIONS, ORIENTATIONS, AND TIME DERIVATIVES **
C ** SUBROUTINE MOLATM **
C ** CONVERTS MOLECULAR COORDINATES INTO ATOMIC SITE POSITIONS **
C ** SUBROUTINE ATMMOL **
C ** CONVERTS ATOMIC FORCES INTO MOLECULAR FORCES AND TORQUES **
C ** **
C ** PRINCIPAL VARIABLES: **
C ** **
C ** REAL DT TIMESTEP **
C ** INTEGER N NUMBER OF MOLECULES **
C ** REAL M MOLECULAR MASS **
C ** REAL IXX,IYY,IZZ PRINCIPAL INERTIAS **
C ** REAL RX(N),RY(N),RZ(N) POSITIONS AT TIME T **
C ** REAL VX(N),VY(N),VZ(N) VELOCITIES AT TIME T **
C ** REAL FX(N),FY(N),FZ(N) C-O-M FORCES **
C ** REAL QW(N),QX(N),QY(N),QZ(N) QUATERNIONS AT TIME T **
C ** REAL JX(N),JY(N),JZ(N) ANGULAR MOM. AT T-DT/2 **
C ** REAL TX(N),TY(N),TZ(N) TORQUE AT T **
C ** REAL K KINETIC ENERGY **
C ** **
C ** USAGE: **
C ** **
C ** WE USE QUATERNION PARAMETERS FOR THE ORIENTATION. **
C ** THIS METHOD USES AN AUXILIARY EQUATION TO OBTAIN ACCURATE **
C ** QUATERNIONS AND ROTATION MATRICES AT THE HALF-STEP TIME. **
C ** ANGULAR MOMENTUM AND TORQUE ARE IN SPACE-FIXED AXES. **
C ** WE ASSUME THAT WE ARE ALSO USING LEAPFROG FOR TRANSLATION **
C ** SUBROUTINE MOLATM IS CALLED, FOLLOWED BY THE FORCE ROUTINE **
C ** (NOT SUPPLIED HERE). AFTER THIS, SUBROUTINE ATMMOL IS CALLED **
C ** AND THEN SUBROUTINE MOVE ADVANCES THE CONFIGURATION. **
C ** FOR THIS EXAMPLE WE TAKE A (NONLINEAR) TRIATOMIC MOLECULE. **
C *******************************************************************
SUBROUTINE MOVE ( DT, M, IXX, IYY, IZZ, K )
COMMON / BLOCK1 / RX, RY, RZ, VX, VY, VZ, FX, FY, FZ
COMMON / BLOCK2 / QW, QX, QY, QZ, JX, JY, JZ, TX, TY, TZ
C *******************************************************************
C ** ADVANCE THE CONFIGURATION AND CALCULATE KINETIC ENERGY **
C *******************************************************************
INTEGER N
PARAMETER ( N = 108 )
REAL DT
REAL M
REAL IXX, IYY, IZZ, K
REAL RX(N), RY(N), RZ(N)
REAL VX(N), VY(N), VZ(N)
REAL FX(N), FY(N), FZ(N)
REAL QW(N), QX(N), QY(N), QZ(N)
REAL JX(N), JY(N), JZ(N)
REAL TX(N), TY(N), TZ(N)
INTEGER I
REAL DT2
REAL JXI, JYI, JZI, OXI, OYI, OZI, QWI, QXI, QYI, QZI
REAL QW1I, QX1I, QY1I, QZ1I, VXI, VYI, VZI
REAL AXX, AXY, AXZ, AYX, AYY, AYZ, AZX, AZY, AZZ
C *******************************************************************
K = 0.0
DT2 = DT / 2.0
DO 400 I = 1, N
C ** AUXILIARY EQUATION MOVES **
C ** ANGULAR MOMENTUM TO TIME T **
JXI = JX(I) + DT2 * TX(I)
JYI = JY(I) + DT2 * TY(I)
JZI = JZ(I) + DT2 * TZ(I)
C ** OBTAIN ROTATION MATRIX AT TIME T **
AXX = QW(I) ** 2 + QX(I) ** 2 - QY(I) ** 2 - QZ(I) ** 2
AXY = 2.0 * ( QX(I) * QY(I) + QW(I) * QZ(I) )
AXZ = 2.0 * ( QX(I) * QZ(I) - QW(I) * QY(I) )
AYX = 2.0 * ( QX(I) * QY(I) - QW(I) * QZ(I) )
AYY = QW(I) ** 2 - QX(I) ** 2 + QY(I) ** 2 - QZ(I) ** 2
AYZ = 2.0 * ( QY(I) * QZ(I) + QW(I) * QX(I) )
AZX = 2.0 * ( QX(I) * QZ(I) + QW(I) * QY(I) )
AZY = 2.0 * ( QY(I) * QZ(I) - QW(I) * QX(I) )
AZZ = QW(I) ** 2 - QX(I) ** 2 - QY(I) ** 2 + QZ(I) ** 2
C ** CONVERT ANGULAR MOMENTUM TO BODY-FIXED **
C ** FORM AND HENCE TO ANGULAR VELOCITIES **
OXI = ( AXX * JXI + AXY * JYI + AXZ * JZI ) / IXX
OYI = ( AYX * JXI + AYY * JYI + AYZ * JZI ) / IYY
OZI = ( AZX * JXI + AZY * JYI + AZZ * JZI ) / IZZ
K = K + IXX * OXI ** 2 + IYY * OYI ** 2 + IZZ * OZI ** 2
C ** OBTAIN TIME-DERIVATIVES OF QUATERNIONS **
C ** AND ADVANCE TO TIME T+DT/2 **
QW1I = ( - QX(I) * OXI - QY(I) * OYI - QZ(I) * OZI ) * 0.5
QX1I = ( QW(I) * OXI - QZ(I) * OYI + QY(I) * OZI ) * 0.5
QY1I = ( QZ(I) * OXI + QW(I) * OYI - QX(I) * OZI ) * 0.5
QZ1I = ( - QY(I) * OXI + QX(I) * OYI + QW(I) * OZI ) * 0.5
QWI = QW(I) + DT2 * QW1I
QXI = QX(I) + DT2 * QX1I
QYI = QY(I) + DT2 * QY1I
QZI = QZ(I) + DT2 * QZ1I
C ** OBTAIN ROTATION MATRIX AT TIME T+DT/2 **
AXX = QWI ** 2 + QXI ** 2 - QYI ** 2 - QZI ** 2
AXY = 2.0 * ( QXI * QYI + QWI * QZI )
AXZ = 2.0 * ( QXI * QZI - QWI * QYI )
AYX = 2.0 * ( QXI * QYI - QWI * QZI )
AYY = QWI ** 2 - QXI ** 2 + QYI ** 2 - QZI ** 2
AYZ = 2.0 * ( QYI * QZI + QWI * QXI )
AZX = 2.0 * ( QXI * QZI + QWI * QYI )
AZY = 2.0 * ( QYI * QZI - QWI * QXI )
AZZ = QWI ** 2 - QXI ** 2 - QYI ** 2 + QZI ** 2
C ** MOVE THE ANGULAR MOMENTA ALL THE WAY **
C ** FROM T-DT/2 TO T+DT/2 AND STORE AWAY **
C ** CONVERT TO BODY-FIXED ANGULAR VELOCITIES **
C ** AT TIME T+DT/2 **
JX(I) = JX(I) + DT * TX(I)
JY(I) = JY(I) + DT * TY(I)
JZ(I) = JZ(I) + DT * TZ(I)
OXI = ( AXX * JX(I) + AXY * JY(I) + AXZ * JZ(I) ) / IXX
OYI = ( AYX * JX(I) + AYY * JY(I) + AYZ * JZ(I) ) / IYY
OZI = ( AZX * JX(I) + AZY * JY(I) + AZZ * JZ(I) ) / IZZ
C ** OBTAIN TIME-DERIVATIVES OF QUATERNIONS **
C ** AND ADVANCE TO T+DT **
QW1I = ( - QXI * OXI - QYI * OYI - QZI * OZI ) * 0.5
QX1I = ( QWI * OXI - QZI * OYI + QYI * OZI ) * 0.5
QY1I = ( QZI * OXI + QWI * OYI - QXI * OZI ) * 0.5
QZ1I = ( - QYI * OXI + QXI * OYI + QWI * OZI ) * 0.5
QW(I) = QW(I) + DT * QW1I
QX(I) = QX(I) + DT * QX1I
QY(I) = QY(I) + DT * QY1I
QZ(I) = QZ(I) + DT * QZ1I
C ** MOVE THE LINEAR VELOCITIES ALL THE WAY **
C ** FROM T-DT/2 TO T+DT/2 AND STORE AWAY **
VXI = VX(I)
VYI = VY(I)
VZI = VZ(I)
VX(I) = VXI + DT * FX(I) / M
VY(I) = VYI + DT * FY(I) / M
VZ(I) = VZI + DT * FZ(I) / M
VXI = 0.5 * ( VXI + VX(I) )
VYI = 0.5 * ( VYI + VY(I) )
VZI = 0.5 * ( VZI + VZ(I) )
K = K + M * ( VXI ** 2 + VYI ** 2 + VZI ** 2 )
C ** ADVANCE POSITIONS TO T+DT **
RX(I) = RX(I) + DT * VX(I)
RY(I) = RY(I) + DT * VY(I)
RZ(I) = RZ(I) + DT * VZ(I)
400 CONTINUE
K = 0.5 * K
RETURN
END
SUBROUTINE MOLATM
COMMON / BLOCK1 / RX, RY, RZ, VX, VY, VZ, FX, FY, FZ
COMMON / BLOCK2 / QW, QX, QY, QZ, JX, JY, JZ, TX, TY, TZ
COMMON / BLOCK3 / DX, DY, DZ, RSX, RSY, RSZ, FSX, FSY, FSZ
C *******************************************************************
C ** COMPUTE ELEMENTS OF ROTATION MATRIX FOR EACH MOLECULE I. **
C ** **
C ** THE TRANSPOSE OF THE ROTATION MATRIX IS USED TO OBTAIN THE **
C ** POSITIONS OF EACH ATOM FROM THE CENTRE-OF-MASS POSITION AND **
C ** THE BODY-FIXED ATOM POSITION VECTORS (KNOWN FROM THE START). **
C ** **
C ** PRINCIPAL VARIABLES: **
C ** **
C ** INTEGER N NUMBER OF MOLECULES **
C ** INTEGER NA NUMBER OF ATOMS PER MOL **
C ** REAL RX(N),RY(N),RZ(N) POSITIONS AT TIME T **
C ** REAL QW(N),QX(N),QY(N),QZ(N) QUATERNIONS AT TIME T **
C ** REAL DX(NA),DY(NA),DZ(NA) ATOM POSITIONS IN MOLEC **
C ** REAL RSX(N,NA),RSY(N,NA),RSZ(N,NA) ATOM POSITIONS **
C *******************************************************************
INTEGER N
PARAMETER ( N = 108 )
INTEGER NA
PARAMETER ( NA = 3 )
REAL RX(N), RY(N), RZ(N)
REAL VX(N), VY(N), VZ(N)
REAL FX(N), FY(N), FZ(N)
REAL QW(N), QX(N), QY(N), QZ(N)
REAL JX(N), JY(N), JZ(N)
REAL TX(N), TY(N), TZ(N)
REAL DX(NA), DY(NA), DZ(NA)
REAL RSX(N,NA), RSY(N,NA), RSZ(N,NA)
REAL FSX(N,NA), FSY(N,NA), FSZ(N,NA)
INTEGER I, A
REAL AXX, AXY, AXZ, AYX, AYY, AYZ, AZX, AZY, AZZ
C *******************************************************************
DO 200 I = 1, N
AXX = QW(I) ** 2 + QX(I) ** 2 - QY(I) ** 2 - QZ(I) ** 2
AXY = 2.0 * ( QX(I) * QY(I) + QW(I) * QZ(I) )
AXZ = 2.0 * ( QX(I) * QZ(I) - QW(I) * QY(I) )
AYX = 2.0 * ( QX(I) * QY(I) - QW(I) * QZ(I) )
AYY = QW(I) ** 2 - QX(I) ** 2 + QY(I) ** 2 - QZ(I) ** 2
AYZ = 2.0 * ( QY(I) * QZ(I) + QW(I) * QX(I) )
AZX = 2.0 * ( QX(I) * QZ(I) + QW(I) * QY(I) )
AZY = 2.0 * ( QY(I) * QZ(I) - QW(I) * QX(I) )
AZZ = QW(I) ** 2 - QX(I) ** 2 - QY(I) ** 2 + QZ(I) ** 2
DO 199 A = 1, NA
RSX(I,A) = RX(I) + AXX * DX(A) + AYX * DY(A) + AZX * DZ(A)
RSY(I,A) = RY(I) + AXY * DX(A) + AYY * DY(A) + AZY * DZ(A)
RSZ(I,A) = RZ(I) + AXZ * DX(A) + AYZ * DY(A) + AZZ * DZ(A)
199 CONTINUE
200 CONTINUE
RETURN
END
SUBROUTINE ATMMOL
COMMON / BLOCK1 / RX, RY, RZ, VX, VY, VZ, FX, FY, FZ
COMMON / BLOCK2 / QW, QX, QY, QZ, JX, JY, JZ, TX, TY, TZ
COMMON / BLOCK3 / DX, DY, DZ, RSX, RSY, RSZ, FSX, FSY, FSZ
C *******************************************************************
C ** CONVERT ATOM FORCES TO TOTAL FORCES AND TORQUES **
C ** **
C ** PRINCIPAL VARIABLES: **
C ** **
C ** INTEGER N NUMBER OF MOLECULES **
C ** INTEGER NA NUMBER OF ATOMS PER MOL **
C ** REAL RX(N),RY(N),RZ(N) POSITIONS AT TIME T **
C ** REAL FX(N),FY(N),FZ(N) C-O-M FORCES **
C ** REAL QW(N),QX(N),QY(N),QZ(N) QUATERNIONS AT TIME T **
C ** REAL TX(N),TY(N),TZ(N) TORQUE AT T **
C ** REAL DX(NA),DY(NA),DZ(NA) ATOM POSITIONS IN MOLEC **
C ** REAL RSX(N,NA),RSY(N,NA),RSZ(N,NA) ATOM POSITIONS **
C ** REAL FSX(N,NA),FSY(N,NA),FSZ(N,NA) FORCES ON EACH ATOM **
C *******************************************************************
INTEGER N
PARAMETER ( N = 108 )
INTEGER NA
PARAMETER ( NA = 3 )
REAL RX(N), RY(N), RZ(N)
REAL VX(N), VY(N), VZ(N)
REAL FX(N), FY(N), FZ(N)
REAL QW(N), QX(N), QY(N), QZ(N)
REAL JX(N), JY(N), JZ(N)
REAL TX(N), TY(N), TZ(N)
REAL DX(NA), DY(NA), DZ(NA)
REAL RSX(N,NA), RSY(N,NA), RSZ(N,NA)
REAL FSX(N,NA), FSY(N,NA), FSZ(N,NA)
INTEGER I, A
REAL RXI, RYI, RZI, FXI, FYI, FZI, TXI, TYI, TZI
REAL FSXIA, FSYIA, FSZIA, RSXIA, RSYIA, RSZIA
C *******************************************************************
DO 300 I = 1, N
FXI = 0.0
FYI = 0.0
FZI = 0.0
TXI = 0.0
TYI = 0.0
TZI = 0.0
RXI = RX(I)
RYI = RY(I)
RZI = RZ(I)
DO 299 A = 1, NA
FSXIA = FSX(I,A)
FSYIA = FSY(I,A)
FSZIA = FSZ(I,A)
RSXIA = RSX(I,A) - RXI
RSYIA = RSY(I,A) - RYI
RSZIA = RSZ(I,A) - RZI
FXI = FXI + FSXIA
FYI = FYI + FSYIA
FZI = FZI + FSZIA
TXI = TXI + RSYIA * FSZIA - RSZIA * FSYIA
TYI = TYI + RSZIA * FSXIA - RSXIA * FSZIA
TZI = TZI + RSXIA * FSYIA - RSYIA * FSXIA
299 CONTINUE
FX(I) = FXI
FY(I) = FYI
FZ(I) = FZI
TX(I) = TXI
TY(I) = TYI
TZ(I) = TZI
300 CONTINUE
RETURN
END
|
