generate_ras Subroutine

public subroutine generate_ras(ras_info, ilut_list, space_size)


Type IntentOptional Attributes Name
type(ras_parameters), intent(inout) :: ras_info
integer(kind=n_int), intent(inout) :: ilut_list(0:,:)
integer, intent(inout) :: space_size


Source Code

Source Code

    subroutine generate_ras(ras_info, ilut_list, space_size)

        ! In: ras - Parameters for the RAS space.
        ! In/Out: ilut_list - List of determinants generated.
        ! In/Out: space_size - Number of determinants in the generated space.
        !             If ilut_list is not empty on input and you want to keep
        !             the states already in it, then on input space_size should
        !             be equal to the number of states to be kept in ilut_list,
        !             and new states will be added in from space_size+1.
        !             Otherwise, space_size must equal 0 on input.
        !             On output space_size will equal the total number of
        !             generated plus what space_size was on input.

        type(ras_parameters), intent(inout) :: ras_info
        integer(n_int), intent(inout) :: ilut_list(0:, :)
        integer, intent(inout) :: space_size

        type(ras_class_data), allocatable, dimension(:) :: ras_classes
        integer(n_int), allocatable, dimension(:, :) :: temp_list
        integer :: temp_size, i

        tot_nelec = nel / 2
        tot_norbs = nbasis / 2

        ! Do a check that the RAS parameters are possible.
        if (ras_info%size_1 + ras_info%size_2 + ras_info%size_3 /= tot_norbs .or. &
            ras_info%min_1 > ras_info%size_1 * 2 .or. &
            ras_info%max_3 > ras_info%size_3 * 2) &
            call stop_all("generate_ras", "RAS parameters are not possible.")

        if (mod(nel, 2) /= 0) call stop_all("generate_ras", "RAS space only implmented for &
                                            & closed shell molecules.")

        call initialise_ras_space(ras_info, ras_classes)

        call find_ras_size(ras_info, ras_classes, temp_size)

        allocate(temp_list(0:NIfTot, temp_size))

        call generate_entire_ras_space(ras_info, ras_classes, temp_size, temp_list)

        do i = 1, temp_size
            call add_state_to_space(temp_list(:, i), ilut_list, space_size)
        end do


    end subroutine generate_ras