Arguments

Type IntentOptional Attributes Name
integer, intent(in) :: nI(nel)
integer, intent(in) :: nJ(nel)
real(kind=dp), intent(in) :: sgn(lenof_sign)

Source Code

    subroutine addProjEContrib(nI, nJ, sgn)
implicit none
integer, intent(in) :: nI(nel), nJ(nel)
real(dp), intent(in) :: sgn(lenof_sign)

integer :: ex(2, 2)
logical :: tPar
integer :: id(2, 2)
integer(int64) :: ind

! kMat reference energy contributions are coming from double excitations
ex(1, 1) = 2

! get the excitation from nI to nJ
call GetExcitation(nI, nJ, nel, ex, tPar)
id = gtID(ex)
! the k-matrix only couples same-spin orbitals
if (tReltvy .or. ((G1(ex(1, 1))%Ms == G1(ex(2, 1))%Ms) .and. &
(G1(ex(1, 2))%Ms == G1(ex(2, 2))%Ms))) then
ind = UMatInd(id(1, 1), id(1, 2), id(2, 1), id(2, 2))
! add the average of the two spawn matrix elements (as this is what is used
! in the energy calculation + dynamics)
kmatProjEContrib(ind) = &
kMatProjEContrib(ind) + sum(sgn) / inum_runs * &
0.5 * (kMat(ind) + kMat(UMatInd(id(1, 2), id(1, 1), id(2, 2), id(2, 1))))
end if
! check the spin, do we have an exchange contribution?
if (tReltvy .or. ((G1(ex(1, 1))%Ms == G1(ex(2, 2))%Ms) .and. &
(G1(ex(1, 2))%Ms == G1(Ex(2, 1))%Ms))) then
ind = UMatInd(id(1, 1), id(1, 2), id(2, 2), id(2, 1))
kmatProjEContrib(ind) = &
kMatProjEContrib(ind) - sum(sgn) / inum_runs * &
0.5 * (kMat(ind) + kMat(UMatInd(id(1, 2), id(1, 1), id(2, 1), id(2, 2))))
end if