Chimie Théorique » OpenPath

subroutine CalcBMat_mixed (natoms, xyzatm, indzmat, dzdc, atmass,atome)

  use Io_module

  use Path_module, only : MW, NCart

  IMPLICIT NONE

  integer(KINT) :: natoms, indzmat(natoms,5),atome(natoms)

  real(KREAL)   :: xyzatm(3,natoms), dzdc(3*natoms,3*natoms),atmass(natoms)

!!!!!!!!!!!!!!!!!!!!!

!

! This routine computes the derivatives of the internal coordinates

! with respect to the cartesian coordinates.

! This is what is called the B matrix in Baker coordinates :

! B(i,j)=dz_i/dx_j

!

! it uses the same routines as Calc_baker

!

! Here, it is used for mixed Cart+Z-mat system

!

!!!!!!!!!!!!!!!!!!!!!!

!

! Input:

! natoms: number of atoms

! xyzatm(3,natoms): cartesian geometry

! indzmat(natoms,5): index of the Z-matrix definition

! atmass(natoms): mass of the atoms

! atome(natoms): ??

!

! Output:

! dzdc(3*natoms,3*natoms): B matrix

!

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

  INTERFACE

     function valid(string) result (isValid)

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

       logical                  :: isValid

     END function VALID

  END INTERFACE

  LOGICAL :: debug

  INTEGER(KINT) :: i,j,k,iat, istart

  INTEGER(KINT) :: iat1, iat2, iat3, iat4

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

  debug=valid('CalcBMat').OR.valid('CalcBMat_mixed')

  if (debug) Call Header('Entering CalcBMat_mixed')

  if (debug) THEN

     WRITE(*,*) 'DBG CalcBMat_mixed Xyzatm '

     DO iat=1,natoms

        write(*,'(1X,I5,3(1X,F15.6))') iat, xyzatm(1:3,iat)

     END DO

     WRITE(*,*) 'DBG CalcBMat_mixed IndZmat'

     DO iat=1,natoms

        write(*,'(6(1X,I5))') iat, indzmat(iat,1:4)

     END DO

  END IF

  dzdc=0.d0

  do i = 1, NCart

     iat=indzmat(i,1)

     do j=1,3

        k=(iat-1)*3+j

        dzdc(k,k)=1.d0

     END DO

  END DO

    IF (NCart.EQ.1) THEN

       if (natoms.ge.2) THEN

          iat1=indzmat(2,1)

          iat2=indzmat(2,2)

          Call CONSTRAINTS_BONDLENGTH_DER(Natoms,iat1,iAT2, xyzatm, dzdc(1,4))

         END IF

    END IF

    IF (NCart.LE.2) THEN

       if (natoms.ge.3) THEN

          iat1=indzmat(3,1)

          iat2=indzmat(3,2)

          iat3=indzmat(3,3)

          Call CONSTRAINTS_BONDLENGTH_DER(Natoms,iat1,iAT2, xyzatm, dzdc(1,7))

          CALL CONSTRAINTS_BONDANGLE_DER(Natoms,iAt1,iAT2,iAt3, xyzatm, dzdc(1,8))

       END IF

    END IF

    IStart=max(NCart+1,4)

    k=(IStart-1)*3+1

  DO I=IStart, Natoms

     iat1=indzmat(i,1)

     iat2=indzmat(i,2)

     iat3=indzmat(i,3)

     iat4=indzmat(i,4)

     Call CONSTRAINTS_BONDLENGTH_DER(Natoms,iat1,iAT2, xyzatm, dzdc(1,k))

     k=k+1

     CALL CONSTRAINTS_BONDANGLE_DER(Natoms,iAt1,iAT2,iAt3, xyzatm, dzdc(1,k))

     k=k+1

     CALL CONSTRAINTS_TORSION_DER2(Natoms,iat1,iat2,iat3,iat4, xyzatm, dzdc(1,k)) 

     k=k+1

  END DO

  if (debug) Call Header('CalcBMat_mixed over')

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

end subroutine CalcBMat_mixed