C SUBROUTINE PREPOT C C System: HO2 C Reference: C. F. Melius and R. J. Blint C Chem. Phys. Lett. 64, 183 (1979). C C PREPOT must be called once before any calls to POT. C The potential parameters are included in DATA statements. C and in the block data subprogram PTPACM. C Coordinates, potential energy, and derivatives are passed C The potential energy in the three asymptotic valleys are C stored in the common block ASYCM: C COMMON /ASYCM/ EASYAB, EASYBC, EASYAC C The potential energy in the AB valley, EASYAB, is equal to the potential C energy of the O "infinitely" far from the HO diatomic, with the C HO diatomic at its equilibrium configuration. Similarly, the terms C EASYBC and EASYAC represent the O2 and the HO asymptotic valleys, C respectively. C The other potential parameters are passed through the common blocks C SATOCM and LEPSCM. C All the information passed through the common blocks PT1CM, ASYCM, C SATOCM, and LEPSCM are in hartree atomic units. C C This potential is written such that: C R(1) = R(H-O) C R(2) = R(O-O) C R(3) = R(O-H) C The classical potential energy is set equal to zero for the H C infinitely far from the equilibrium O2 diatomic. C C The flags that indicate what calculations should be carried out in C the potential routine are passed through the common block PT2CM: C where: C NASURF - which electronic states availalble C (1,1) = 1 as only gs state available C NDER = 0 => no derivatives should be calculated C NDER = 1 => calculate first derivatives C NFLAG - these integer values can be used to flag options C within the potential; C C C Potential parameters' default settings C Variable Default value C NDER 1 C NFLAG(18) 6 C CCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C GENERAL INFORMATION CCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C C THE POTENTIAL CONSISTS OF THREE MORSE TERMS FOR C THE THREE DIATOMICS, HO,OO, AND HO RESPECTIVELY C PLUS TWO INTERACTION TERMS. C C EACH POTENTIAL TERM WILL BE CALCULATED INDIVIDUALLY C TO SIMPLIFY READING THE CODE. C CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C DEFINE VARIABLES, ARRAYS, AND COMMON BLOCK CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C IMPLICIT REAL*8 (A-H,O-Z) C CHARACTER*75 REF(5) C PARAMETER (N3ATOM = 75) PARAMETER (ISURF = 5) PARAMETER (JSURF = ISURF*(ISURF+1)/2) PARAMETER (PI = 3.141592653589793D0) PARAMETER (NATOM = 25) C COMMON /PT3CM/ EZERO(ISURF+1) C COMMON/INFOCM/ CARTNU(NATOM,3),INDEXES(NATOM), + IRCTNT,NATOMS,ICARTR,MDER,MSURF,REF C C COMMON/USRICM/ CART(NATOM,3),ANUZERO, + NULBL(NATOM),NFLAG(20), + NASURF(ISURF+1,ISURF+1),NDER C COMMON /ASYCM/ EASYAB,EASYBC,EASYAC C REAL*8 NUM,DENOM,GAMMA,JUNK,EXPO,DEXPO,MEW C C C COMMON /POTCM/ C(5,3,3),DE(3),GAMMA(3),REQ(3), + ZEROAD,ALPHA,BETA COMMON /PRECM/ DCSTH(3),DV(3),JUNK(4),A(5), + DA(5,3),EXPO(3),DEXPO(3),DMEW(3), + B(5,3),DB(5,3,3),DPROD1(3), + DPROD2(3),DSEC(3),DTHIRD(3), + DPROD3(3),ZKCAL C IF(NATOMS.GT.25) THEN WRITE(NFLAG(18),1111) 1111 FORMAT(2X,'STOP. NUMBER OF ATOMS EXCEEDS ARRAY DIMENSIONS') STOP END IF C C C Initialize the potential values in the three asymptotic valleys. C EASYAB = DE(1) EASYBC = DE(2) EASYAC = DE(3) C C Echo potential parameters to unit IPRT. C WRITE (NFLAG(18), 1000) WRITE (NFLAG(18),1050) (DE(IT),IT=1,3) WRITE (NFLAG(18),1150) (GAMMA(IT),IT=1,3) WRITE (NFLAG(18),1200) (REQ(IT),IT=1,3) C 1000 FORMAT (/, 2X, T5, 'PREPOT has been called for H + OO', * /, 2X, T5, 'Potential energy function by Melius ', * 'and Blint', * //, 2X, T5, 'Potential energy surface parameters:', * /, 2X, T10, 'Bond', T47, 'H-O', T58, 'O-O', T69, 'O-H') 1050 FORMAT(2X,T10,'Dissociation energies (hartrees):', * T44, F10.5, T55, F10.5, T66, F10.5) 1150 FORMAT(2X,T10,'Morse betas (reciprocal bohr):', * T44, F10.5, T55, F10.5, T66, F10.5) 1200 FORMAT(2X,T10,'Equilibrium bond lengths (bohr):', * T44, F10.5, T55, F10.5, T66, F10.5) C C Convert ZEROAD to eV and kcal/mol and echo to unit IPRT. C ZEV = ZEROAD*27.21106D0 ZKCAL = ZEROAD*627.5095D0 WRITE (NFLAG(18),1300) ZEROAD,ZEV,ZKCAL C 1300 FORMAT(/,2X,T10,'Constant added to the energy:', * /,T38, 1PE20.12,' hartree atomic units', * /,T38, 1PE20.12,' eV',/,T38,1PE20.12,' kcal/mol') C CCCCCCCCCCCC C C EZERO(1)=DE(2) C DO I=1,5 REF(I) = ' ' END DO C REF(1)='C. F. Melius and R. J. Blint' REF(2)='Chem. Phys. Lett. 64, 183(1979)' C INDEXES(1) = 1 INDEXES(2) = 8 INDEXES(3) = 8 C C C IRCTNT=2 C CALL POTINFO C CALL ANCVRT C RETURN END C CCCCCCCCCCCC C CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C MOVE ONTO POT SUBROUTINE CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C SUBROUTINE POT C C The potential energy in the AB valley, EASYAB, is equal to the potential C energy of the O "infinitely" far from the HO diatomic, with the C HO diatomic at its equilibrium configuration. Similarly, the terms C EASYBC and EASYAC represent the O2 and the HO asymptotic valleys, C respectively. C C C This potential is written such that: C R(1) = R(H-O) C R(2) = R(O-O) C R(3) = R(O-H) C The classical potential energy is set equal to zero for the H C infinitely far from the equilibrium O2 diatomic. C C ENTRY POT IMPLICIT REAL*8 (A-H,O-Z) C CHARACTER*75 REF(5) C PARAMETER (N3ATOM = 75) PARAMETER (ISURF = 5) PARAMETER (JSURF = ISURF*(ISURF+1)/2) PARAMETER (PI = 3.141592653589793D0) PARAMETER (NATOM = 25) C COMMON /PT1CM/ R(N3ATOM),ENGYGS,DEGSDR(N3ATOM) COMMON /PT3CM/ EZERO(ISURF+1) COMMON /PT4CM/ ENGYES(ISURF),DEESDR(N3ATOM,ISURF) COMMON /PT5CM/ ENGYIJ(JSURF),DEIJDR(N3ATOM,JSURF) C COMMON/INFOCM/ CARTNU(NATOM,3),INDEXES(NATOM), + IRCTNT,NATOMS,ICARTR,MDER,MSURF,REF C COMMON/USROCM/ PENGYGS,PENGYES(ISURF), + PENGYIJ(JSURF), + DGSCART(NATOM,3),DESCART(NATOM,3,ISURF), + DIJCART(NATOM,3,JSURF) C COMMON/USRICM/ CART(NATOM,3),ANUZERO, + NULBL(NATOM),NFLAG(20), + NASURF(ISURF+1,ISURF+1),NDER C COMMON /ASYCM/ EASYAB,EASYBC,EASYAC C REAL*8 NUM,DENOM,GAMMA,JUNK,EXPO,DEXPO,MEW C C C COMMON /POTCM/ C(5,3,3),DE(3),GAMMA(3),REQ(3), + ZEROAD,ALPHA,BETA COMMON /PRECM/ DCSTH(3),DV(3),JUNK(4),A(5), + DA(5,3),EXPO(3),DEXPO(3),DMEW(3), + B(5,3),DB(5,3,3),DPROD1(3), + DPROD2(3),DSEC(3),DTHIRD(3), + DPROD3(3),ZKCAL C CALL CARTOU CALL CARTTOR C C Check the values of NASURF and NDER for validity. C IF (NASURF(1,1) .EQ. 0) THEN WRITE(NFLAG(18), 900) NASURF(1,1) STOP ENDIF IF (NDER .GT. 1) THEN WRITE (NFLAG(18), 910) NDER STOP 'SURF 2' ENDIF C CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C SET RAB,RBC,AND RAC CCCCCCCCCCCCCCCCCCCCCCCCCCCCC C RBC = R(2) C C RAB IS DEFINED AS THE SMALLER OF R(1) AND R(3) C RAC IS DEFINED AS THE LARGER OF R(1) AND R(3) C IF (R(1).GT.R(3)) GO TO 40 C RAB = R(1) RAC = R(3) GO TO 50 C 40 RAB = R(3) RAC = R(1) 50 CONTINUE C CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C CALCULATE USEFUL EXPONENTIALS CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C EXPO(1) = EXP(-ALPHA*RAB) EXPO(2) = EXP(-BETA*RBC) EXPO(3) = EXP(-ALPHA*RAC) C C AND THEIR DERIVATIVES C IF (NDER .EQ. 1) THEN DEXPO(1) = -ALPHA*EXPO(1) DEXPO(2) = -BETA*EXPO(2) DEXPO(3) = -ALPHA*EXPO(3) ENDIF C CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C CALCULATE VAB AND DV(1) CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C C THE POTENTIAL CALCULATED HERE AND THE POTENTIALS VAC AND VBC C CORRESPOND TO THE VOH POTENTIAL DESCRIBED IN EQUATION 3. C DV(1) IS THE DERIVATIVE OF THIS TERM WITH RESPECT TO RAB. C JUNK(1) = EXP(GAMMA(1)*(REQ(1)-RAB)) VAB = DE(1)*(JUNK(1)*JUNK(1)-2.0D0*JUNK(1)) IF (NDER .EQ. 1) * DV(1) = 2.0D0*DE(1)*(1.0D0-JUNK(1))*GAMMA(1)*JUNK(1) C CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C CALCULATE VAC AND DV(3) CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C JUNK(1) = EXP(GAMMA(3)*(REQ(3)-RAC)) VAC = DE(3)*(JUNK(1)*JUNK(1)-2.0D0*JUNK(1)) IF (NDER .EQ. 1) * DV(3) = 2.0D0*DE(3)*(1.0D0-JUNK(1))*GAMMA(3)*JUNK(1) C CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C CALCULATE VBC AND DV(2) CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C JUNK(1) = EXP(GAMMA(2)*(REQ(2)-RBC)) VBC = DE(2)*(JUNK(1)*JUNK(1)-2.0D0*JUNK(1)) IF (NDER .EQ. 1) * DV(2) = -2.0D0*DE(2)*(JUNK(1)-1.0D0)*GAMMA(2)*JUNK(1) C CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C CALCULATE CSTH AND DERIVATIVES CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C C TH IS THE BEND ANGLE OF THE THREE ATOM SYSTEM. C IT IS NEVER USED EXPLICITELY WITHIN THE PROGRAM C HOWEVER COSINE(TH) IS. COSINE(TH) IS CALCULATED C FROM THE LAW OF COSINES) C NUM = RBC*RBC+RAB*RAB-RAC*RAC DENOM = 2.0D0*RAB*RBC C CSTH = NUM/DENOM C IF (NDER .EQ. 1) THEN DCSTH(1) = (2.0D0*RAB/DENOM)-(2.0D0*RBC)*CSTH/DENOM DCSTH(2) = (2.0D0*RBC/DENOM)-(2.0D0*RAB)*CSTH/DENOM DCSTH(3) = -(2.0D0*RAC/DENOM) ENDIF C CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C CALCULATE THE B IJ 'S--SEE EQUATION 5 CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C DO 80 I = 1, 5 DO 70 J = 1, 3 B(I,J) = C(I,J,1)*(1.0D0+C(I,J,2)*CSTH*(1.0D0+C(I,J,3)* * CSTH)) C C CALCULATE THE DERIVATIVES TOO. C IF (NDER .EQ. 1) THEN DO 60 IT = 1, 3 DB(I,J,IT) = C(I,J,1)*C(I,J,2)*(CSTH*C(I,J,3)* * DCSTH(IT)+DCSTH(IT)* * (1.0D0+C(I,J,3)*CSTH)) 60 CONTINUE ENDIF 70 CONTINUE 80 CONTINUE C CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C NEXT CALCULATE MEW--SEE EQUATION FOUR CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C MEW = EXPO(2)-0.02538745816335D0 IF (NDER .EQ. 1) THEN DMEW(2) = -BETA*EXPO(2) DMEW(1) = 0.0D0 DMEW(3) = 0.0D0 ENDIF C CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C NOW CALCULATE A I 'S AND DERIVATIVES--SEE EQUATION 4 CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C DO 100 IT = 1, 5 JUNK(1) = 1.0D0+B(IT,3)*MEW JUNK(2) = MEW*B(IT,2) JUNK(3) = 1.0D0+JUNK(2)*JUNK(1) C A(IT) = B(IT,1)*JUNK(3) IF (NDER .EQ. 1) THEN DO 90 IT1 = 1, 3 DA(IT,IT1) = DB(IT,1,IT1)*JUNK(3)+B(IT,1)* * ((DB(IT,2,IT1)*MEW+B(IT,2)*DMEW(IT1))* * JUNK(1)+JUNK(2)*(DB(IT,3,IT1)*MEW+ * B(IT,3)*DMEW(IT1))) 90 CONTINUE ENDIF 100 CONTINUE C CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C CALCULATE THE SECOND TERM IN EQUATION THREE CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C PROD1 = EXPO(1)*EXPO(3)*A(1) C PROD2 = 1.0D0+(A(3)*RAB*RAC)/(RAB+RAC) C IF (NDER .EQ. 1) THEN DPROD1(1) = DEXPO(1)*EXPO(3)*A(1)+EXPO(1)*EXPO(3)*DA(1,1) DPROD1(2) = EXPO(1)*EXPO(3)*DA(1,2) DPROD1(3) = DEXPO(3)*EXPO(1)*A(1)+EXPO(1)*EXPO(3)*DA(1,3) C DPROD2(2) = (DA(3,2)*RAB*RAC)/(RAB+RAC) DPROD2(1) = ((DA(3,1)*RAB*RAC+A(3)*RAC)*(RAB+RAC)- * (A(3)*RAB*RAC))/((RAB+RAC)*(RAB+RAC)) DPROD2(3) = ((DA(3,3)*RAB*RAC+A(3)*RAB)*(RAB+RAC)- * (A(3)*RAB*RAC))/((RAB+RAC)*(RAB+RAC)) ENDIF C C CALCULATE PROD3 C PROD3 = 1.0D0+A(2)*(RAB+RAC)*PROD2 C IF (NDER .EQ. 1) THEN DO 120 IT = 1, 3 DPROD3(IT) = DA(2,IT)*(RAB+RAC)*PROD2+A(2)* * (RAB+RAC)*DPROD2(IT) IF (IT.EQ.2) GO TO 110 DPROD3(IT) = DPROD3(IT)+A(2)*PROD2 110 CONTINUE 120 CONTINUE ENDIF C SECOND = PROD1*PROD3 C IF (NDER .EQ. 1) THEN DO 130 IT = 1, 3 DSEC(IT) = PROD1*DPROD3(IT)+DPROD1(IT)*PROD3 130 CONTINUE ENDIF C CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C CALCULATE THE THIRD TERM CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C JUNK(1) = EXPO(1)+EXPO(3) JUNK(2) = (1.0D0+A(5)*(RAB+RAC)) C THIRD = JUNK(1)*EXPO(2)*A(4)*JUNK(2) C IF (NDER .EQ. 1) THEN DO 140 IT1 = 1, 2 IT = 1 IF (IT1.EQ.2) IT = 3 DTHIRD(IT) = DEXPO(IT)*EXPO(2)*A(4)*JUNK(2)+ * JUNK(1)*EXPO(2)*DA(4,IT)*JUNK(2)+ * JUNK(1)*EXPO(2)*A(4)*(DA(5,IT)* * (RAB+RAC)+A(5)) 140 CONTINUE DTHIRD(2) = JUNK(1)*(DEXPO(2)*A(4)*JUNK(2)+EXPO(2)*(DA(4,2)* * JUNK(2)+A(4)*(DA(5,2)*(RAB+RAC)))) ENDIF C CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C FINALLY SUM IT ALL UP CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C ENGYGS = VAB+VAC+VBC+SECOND+THIRD+ EZERO(1) ENGYGS = ENGYGS+ZEROAD C IF (NDER .EQ. 1) THEN DO 150 IT = 1, 3 DEGSDR(IT) = DV(IT)+DSEC(IT)+DTHIRD(IT) 150 CONTINUE C IF (R(1).LT.R(3)) GO TO 160 JUNK(1) = DEGSDR(3) DEGSDR(3) = DEGSDR(1) DEGSDR(1) = JUNK(1) 160 CONTINUE ENDIF C CCCCCCCCCCCCCCCC C CALL EUNITZERO IF(NDER.NE.0) THEN CALL RTOCART CALL DEDCOU ENDIF C RETURN C CCCCCCCCCCCCCCCC C 1000 FORMAT (/, 2X, T5, 'PREPOT has been called for H + OO', * /, 2X, T5, 'Potential energy function by Melius ', * 'and Blint', * //, 2X, T5, 'Potential energy surface parameters:', * /, 2X, T10, 'Bond', T47, 'H-O', T58, 'O-O', T69, 'O-H') 1050 FORMAT(2X,T10,'Dissociation energies (hartrees):', * T44, F10.5, T55, F10.5, T66, F10.5) 1150 FORMAT(2X,T10,'Morse betas (reciprocal bohr):', * T44, F10.5, T55, F10.5, T66, F10.5) 1200 FORMAT(2X,T10,'Equilibrium bond lengths (bohr):', * T44, F10.5, T55, F10.5, T66, F10.5) 1300 FORMAT(/,2X,T10,'Constant added to the energy:', * /,T38, 1PE20.12,' hartree atomic units', * /,T38, 1PE20.12,' eV',/,T38,1PE20.12,' kcal/mol') 900 FORMAT(/,2X,T5,13HNASURF(1,1) =,I5, * /,2X,T5,24HThis value is unallowed. * /,2X,T5,31HOnly gs surface=>NASURF(1,1)=1 ) 910 FORMAT(/, 2X,'POT has been called with NDER = ',I5, * /, 2X, 'This value of NDER is not allowed in this ', * 'version of the potential.') C END C C***** C BLOCK DATA PTPACM IMPLICIT REAL*8 (A-H,O-Z) C CHARACTER*75 REF(5) REAL*8 JUNK C PARAMETER (N3ATOM = 75) PARAMETER (ISURF = 5) PARAMETER (JSURF = ISURF*(ISURF+1)/2) PARAMETER (PI = 3.141592653589793D0) PARAMETER (NATOM = 25) C COMMON /PT3CM/ EZERO(ISURF+1) C COMMON/INFOCM/ CARTNU(NATOM,3),INDEXES(NATOM), + IRCTNT,NATOMS,ICARTR,MDER,MSURF,REF C C COMMON/USRICM/ CART(NATOM,3),ANUZERO, + NULBL(NATOM),NFLAG(20), + NASURF(ISURF+1,ISURF+1),NDER C COMMON /ASYCM/ EASYAB,EASYBC,EASYAC C COMMON /POTCM/ C(5,3,3),DE(3),GAMMA(3),REQ(3), + ZEROAD,ALPHA,BETA COMMON /PRECM/ DCSTH(3),DV(3),JUNK(4),A(5), + DA(5,3),EXPO(3),DEXPO(3),DMEW(3), + B(5,3),DB(5,3,3),DPROD1(3), + DPROD2(3),DSEC(3),DTHIRD(3), + DPROD3(3),ZKCAL C C Initialize the flags and the I/O unit numbers for the potential C DATA NASURF /1,35*0/ DATA NDER /0/ DATA NFLAG /1,1,15*0,6,0,0/ C DATA ANUZERO /0.0D0/ DATA ICARTR,MSURF,MDER/3,0,1/ DATA NULBL /25*0/ DATA NATOMS /3/ C CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C Initialize the constants CCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCCC C DATA C / 77.45D0, -0.4071D0, -0.508D0, * 0.1489D0, 1.013D0, -10.495D0, * 9.1484D0, 10.273D0, 0.0D0, + 0.0D0, -3.050D0, -33.78D0, + -22.951D0, 0.0D0, 0.0D0, + -1.3699D0, 0.4101D0, 0.3411D0, * 16.906D0, 0.0005637D0, -0.6359D0, * -0.06253D0, -0.1225D0, 0.0D0, + 0.0D0, -0.00906D0, 0.4435D0, + 0.7439D0, 0.0D0, 0.0D0, * -0.3498D0, 0.6617D0, 0.8677D0, + 1.3858D0, 233.36D0, -4.756D0, + -1.626D0, 0.6337D0, 0.0D0, + 0.0D0, -476.32D0, -1.2104D0, + -1.2762D0, 0.0D0, 0.0D0 / C C The array DE contains the dissociation energies in hartree atomic units. C DATA DE / 0.1559D0, 0.1779D0, 0.1559D0/ C C The array GAMMA contains the Morse Betas in reciprocal bohrs. C DATA GAMMA / 1.2670D0, 1.4694D0, 1.2670D0/ C C The array REQ contains the equilibrium bond lengths in bohr. C DATA REQ / 1.8460D0, 2.3158D0, 1.8460D0/ C C The variable ZEROAD contains the constant C added to the energy in hartree atomic units. C DATA ZEROAD /-0.022000295721D0/ C C SET ALPHA, UNITS: RECIPROCAL BOHR C DATA ALPHA /0.9172D0/ C C SET BETA, UNITS: RECIPROCAL BOHR C DATA BETA /1.4694D0/ C END C C*****