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QuAcK/src/eDFT/unrestricted_fock_exchange_energy.f90

26 lines
530 B
Fortran

subroutine unrestricted_fock_exchange_energy(nBas,P,Fx,Ex)
! Compute the (exact) Fock exchange energy
implicit none
! Input variables
integer,intent(in) :: nBas
double precision,intent(in) :: P(nBas,nBas)
double precision,intent(in) :: Fx(nBas,nBas)
! Local variables
double precision,external :: trace_matrix
! Output variables
double precision,intent(out) :: Ex
! Compute HF exchange energy
Ex = 0.5d0*trace_matrix(nBas,matmul(P,Fx))
end subroutine unrestricted_fock_exchange_energy