apply_rotation_wf Function

    function apply_rotation_wf(ilut_list, rot_angle) result(rot_wf)
        ! function to apply a rotation of given angle to the whole wavefunction
        ! encoded in ilut_list
        integer(n_int), intent(inout) :: ilut_list(:, :)
        real(dp), intent(in) :: rot_angle
        integer(n_int) :: rot_wf(size(ilut_list, 1), size(ilut_list, 2))
#ifdef DEBUG_
        character(*), parameter :: this_routine = "apply_rotation_wf"
#endif
        integer :: orig_orbs(nBasis / 2), trans_orbs(nBasis / 2), i, &
                   orig_states(nel, size(ilut_list, 2)), rot_states(nel, size(ilut_list, 2))
        real(dp) :: orig_weights(size(ilut_list, 2)), temp_sign(lenof_sign), &
                    rot_weights(size(ilut_list, 2))

        orig_orbs = get_spatial(brr(1:nBasis:2))

        trans_orbs = apply_rotation(orig_orbs, rot_angle)

        ! decode the original information
        do i = 1, size(ilut_list, 2)
            call decode_bit_det(orig_states(:, i), ilut_list(:, i))
            call extract_sign(ilut_list(:, i), temp_sign)
            orig_weights(i) = temp_sign(1)
        end do

        call transform_states(orig_orbs, trans_orbs, size(ilut_list, 2), &
                              orig_states, orig_weights, ilut_list, rot_states, rot_weights, rot_wf)

    end function apply_rotation_wf