mirror of
https://github.com/pfloos/quack
synced 2024-11-13 09:34:04 +01:00
37 lines
661 B
Fortran
37 lines
661 B
Fortran
|
subroutine CCSD_correlation_energy(nC,nO,nV,nR,OOVV,tau,EcCCSD)
|
||
|
|
|
||
|
|
! Compute the CCSD energy
|
||
|
|
|
||
|
|
implicit none
|
||
|
|
|
||
|
|
! Input variables
|
||
|
|
|
||
|
|
integer,intent(in) :: nC,nO,nV,nR
|
||
|
|
double precision,intent(in) :: OOVV(nO,nO,nV,nV)
|
||
|
|
double precision,intent(in) :: tau(nO,nO,nV,nV)
|
||
|
|
|
||
|
|
! Local variables
|
||
|
|
|
||
|
|
integer :: i,j,a,b
|
||
|
|
|
||
|
|
! Output variables
|
||
|
|
|
||
|
|
double precision,intent(out) :: EcCCSD
|
||
|
|
|
||
|
|
EcCCSD = 0d0
|
||
|
|
do i=nC+1,nO
|
||
|
|
do j=nC+1,nO
|
||
|
|
do a=1,nV-nR
|
||
|
|
do b=1,nV-nR
|
||
|
|
|
||
|
|
EcCCSD = EcCCSD + OOVV(i,j,a,b)*tau(i,j,a,b)
|
||
|
|
|
||
|
|
enddo
|
||
|
|
enddo
|
||
|
|
enddo
|
||
|
|
enddo
|
||
|
|
|
||
|
|
EcCCSD = 0.5d0*EcCCSD
|
||
|
|
|
||
|
|
end subroutine CCSD_correlation_energy
|