mirror of
https://github.com/pfloos/quack
synced 2024-07-07 20:05:58 +02:00
42 lines
846 B
Fortran
42 lines
846 B
Fortran
|
subroutine fock_exchange_individual_energy(nBas,P,ERI,Ex)
|
||
|
|
|
||
|
|
! Compute the Fock exchange potential
|
||
|
|
|
||
|
|
implicit none
|
||
|
|
|
||
|
|
! Input variables
|
||
|
|
|
||
|
|
integer,intent(in) :: nBas
|
||
|
|
double precision,intent(in) :: P(nBas,nBas)
|
||
|
|
double precision,intent(in) :: ERI(nBas,nBas,nBas,nBas)
|
||
|
|
|
||
|
|
! Local variables
|
||
|
|
|
||
|
|
integer :: mu,nu,la,si
|
||
|
|
double precision,allocatable :: Fx(:,:)
|
||
|
|
double precision,external :: trace_matrix
|
||
|
|
|
||
|
|
! Output variables
|
||
|
|
|
||
|
|
double precision,intent(out) :: Ex
|
||
|
|
|
||
|
|
! Compute HF exchange matrix
|
||
|
|
|
||
|
|
allocate(Fx(nBas,nBas))
|
||
|
|
|
||
|
|
Fx(:,:) = 0d0
|
||
|
|
|
||
|
|
do si=1,nBas
|
||
|
|
do la=1,nBas
|
||
|
|
do nu=1,nBas
|
||
|
|
do mu=1,nBas
|
||
|
|
Fx(mu,nu) = Fx(mu,nu) + P(la,si)*ERI(mu,la,si,nu)
|
||
|
|
enddo
|
||
|
|
enddo
|
||
|
|
enddo
|
||
|
|
enddo
|
||
|
|
|
||
|
|
Ex = -0.25d0*trace_matrix(nBas,matmul(P,Fx))
|
||
|
|
|
||
|
|
end subroutine fock_exchange_individual_energy
|