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QuAcK/src/eDFT/unrestricted_density_matrix.f90

48 lines
1.2 KiB
Fortran

subroutine unrestricted_density_matrix(nBas,nEns,nO,c,P)
! Calculate density matrices
implicit none
include 'parameters.h'
! Input variables
integer,intent(in) :: nBas
integer,intent(in) :: nEns
integer,intent(in) :: nO(nspin)
double precision,intent(in) :: c(nBas,nBas,nspin)
! Local variables
integer :: ispin
integer :: iEns
! Output variables
double precision,intent(out) :: P(nBas,nBas,nspin,nEns)
! Ground state density matrix
iEns = 1
do ispin=1,nspin
P(:,:,ispin,iEns) = matmul(c(:,1:nO(ispin),ispin),transpose(c(:,1:nO(ispin),ispin)))
end do
! Singly-excited state density matrix
iEns = 2
P(:,:,1,iEns) = matmul(c(:,1:nO(1)-1,1),transpose(c(:,1:nO(1)-1,1))) &
+ matmul(c(:,nO(1)+1:nO(1)+1,1),transpose(c(:,nO(1)+1:nO(1)+1,1)))
P(:,:,2,iEns) = matmul(c(:,1:nO(2),2),transpose(c(:,1:nO(2),2)))
! Doubly-excited state density matrix
iEns = 3
do ispin=1,nspin
P(:,:,ispin,iEns) = matmul(c(:,1:nO(ispin)-1,ispin),transpose(c(:,1:nO(ispin)-1,ispin))) &
+ matmul(c(:,nO(ispin)+1:nO(ispin)+1,ispin),transpose(c(:,nO(ispin)+1:nO(ispin)+1,ispin)))
end do
end subroutine unrestricted_density_matrix