Chimie Théorique » OpenPath

subroutine egrad_mopac(e,geomcart,gradcart)

  ! This routines calculates the energy and the gradient of 

  ! a molecule, using mopac 

  use Path_module, only : Nat, renum,Order,OrderInv,AtName, Coord, dzdc, indzmat,Nom,Atome, massat, unit,ProgExe, au2kcal

  use Io_module

  IMPLICIT NONE

  ! Energy (calculated if F300K=.F., else estimated)

  REAL(KREAL), INTENT (OUT) :: e

  ! Nb degree of freedom

  REAL(KREAL), INTENT (IN) :: geomcart(Nat,3)

  ! Gradient calculated at Geom geometry

  REAL(KREAL), INTENT (OUT) :: gradcart(3*NAt)

  ! ======================================================================

  character(LCHARS) :: LINE

  logical           :: debug

  LOGICAL, SAVE :: first=.true.

  REAL(KREAL), ALLOCATABLE :: GradTmp(:)

  REAL(KREAL) :: d, a_val, Pi

  REAL(KREAL) :: coef,x

  INTEGER(KINT) :: iat, jat, kat, i, j, k,n3at

  INTEGER(KINT) :: ITmp1,ITmp2, Idx

  INTEGER(KINT), PARAMETER :: IOLOG=12, IOCOM=11

  CHARACTER(132) :: FileIn, FileOut, FileChk

  CHARACTER(3) :: SepIn=' < ', SepOut=' > '

  CHARACTER(VLCHARS), SAVE ::  RunCommand

  ! ======================================================================

  INTERFACE

     function valid(string) result (isValid)

       CHARACTER(*), intent(in) :: string

       logical                  :: isValid

     END function VALID

  END INTERFACE

  ! ======================================================================

  Pi=dacos(-1.0d0)

  n3at=3*nat

  debug=valid('EGRAD')

  if (debug) WRITE(*,*) '================ Entering Egrad_Mopac ===================='

  if (first) THEN

     First=.FALSE.

     SepIn='   '

     SepOut='   '

  END IF

  gradcart=0.

  E=0.

  FileIn=Trim(CalcName) // "." // Trim(ISuffix)

  FileOut=Trim(CalcName) // "." // Trim(OSuffix)

  FileChk=Trim(CalcName) // ".arc"

  RunCommand=Trim(ProgExe) // SepIn // Trim(FileIn) 

  IF (DEBUG) WRITE(*,*)'RunCommand:',TRIM(RunCommand)

  ! we create the input file

  OPEN(IOTMP,File=FileIn)

  WRITE(IOTMP,'(A)') '* All comments are put at the begining of the file'

  Current => Mopac_comment

  DO WHILE (ASSOCIATED(Current%next))

     WRITE(IOTMP,'(A)') Trim(current%line)

     Current => current%next

  END DO

  Current => Mopac_root

  DO WHILE (ASSOCIATED(Current%next))

     WRITE(IOTMP,'(1X,A)') Trim(current%line)

     WRITE(*,'(1X,A)') Trim(current%line)

     Current => current%next

  END DO

  DO I=1,Nat

     If (renum) THEN

        Iat=Order(I)

        WRITE(IOTMP,'(1X,A10,3(1X,F15.8))') Trim(AtName(I)),GeomCart(Iat,:)

     ELSE

        Iat=OrderInv(I)

        WRITE(IOTMP,'(1X,A10,3(1X,F15.8))') Trim(AtName(Iat)),GeomCart(I,:)

     END IF

  END DO

     WRITE(IOTMP,'(1X,A)') Trim(Mopac_EndGeom)

  Current => Mopac_End

  DO WHILE (ASSOCIATED(Current%next))

     WRITE(IOTMP,'(1X,A)') Trim(current%line)

     Current => current%next

  END DO

  WRITE(IOTMP,*) 

  CLOSE(IOTMP)

  IF (debug) THEN

     WRITE(*,*) 'DBG EGRAD ' //  Trim(FileIn),' COORD=',TRIM(COORD)

     call system('cat ' // Trim(FileIn))

  END IF

  call system(RunCommand)

  if (debug) WRITE(*,*) 'DBG EGRAD, back from calculation'

  ! Whatever the coordinate system, we read the cartesian gradient

  ! and we convert it to Zmat or other if needed

  OPEN(IOTMP,FILE=FileOut, STATUS='old')

  ! We first search for the forces

  READ(IOTMP,'(A)') LINE

  DO WHILE (INDEX(LINE,'FINAL  POINT  AND  DERIVATIVES')==0)

     IF (INDEX(Line,'FINAL HEAT OF FORMATION').NE.0)  THEN

        Itmp1=Index(Line,"=")+1

        ITmp2=Index(Line,"KCAL")-1

        Read(Line(Itmp1:Itmp2),*) E

        E=E/au2kcal

     END IF

     READ(IOTMP,'(A)',END=999) LINE

  END DO

  if (debug) WRITE(*,*) "GradCart reading - renum=",Renum

  READ(IOTMP,'(A)') LINE

  READ(IOTMP,'(A)') LINE

  DO I=1,Nat

     Iat=I

     IF (renum) Iat=Order(I)

     DO J=1,3

        READ(IOTMP,'(A)') Line

! Gradient is on the 7th column

        DO K=1,6

           Line=AdjustL(Line)

           Idx=Index(Line," ")

           Line=AdjustL(Line(Idx+1:))

        END DO

        READ(Line,*) GradCart(3*Iat-3+j)

     END DO

     if (debug) WRITE(*,*) "I,Iat,GradCart:",I,Iat,GradCart(3*Iat-2:3*Iat)

  END DO

! Mopac gives the Forces in kcal/angstrom, so we convert it into the 

! gradient in ua/Angstrom 

  gradCart=gradCart/au2kcal

!  if (debug.AND.(COORD.EQ.'ZMAT')) THEN

!     DO WHILE (INDEX(LINE,'Internal Coordinate Forces')==0)

!        READ(IOTMP,'(A)') LINE

!!        WRITE(*,*) 'Pas bon:' // TRIM(LINE)

!     END DO

!     WRITE(*,*) TRIM(LINE)

!     DO I=1,Nat+2

!        READ(IOTMP,'(A)') LINE

!        WRITE(*,*) TRIM(LINE)

!     END DO

!  END IF

  CLOSE(IOTMP)

  if (debug) WRITE(*,*) '================  Egrad_Mopac Over ===================='

  RETURN

999 CONTINUE

  WRITE(*,*) 'We should not be here !!!!'

  STOP

  ! ======================================================================

end subroutine egrad_mopac