count_alpha_orbs_ij Function

    function count_alpha_orbs_ij(csf_i, i, j) result(nOpen)
        ! function to count the number of 2s in a CSF det between spatial
        ! orbitals i and j
        type(CSF_Info_t), intent(in) :: csf_i
        integer, intent(in) :: i, j
        integer :: nOpen
        character(*), parameter :: this_routine = "count_alpha_orbs_ij"

        integer :: k

        ASSERT(i > 0 .and. i <= nSpatOrbs)
        ASSERT(j > 0 .and. j <= nSpatOrbs)

        nOpen = 0

        ! quick fix for now to see if thats the problem: loop and check!
        do k = i, j
            if (csf_i%stepvector(k) == 2) then
                nOpen = nOpen + 1
            end if
        end do
    end function count_alpha_orbs_ij