find_switches_stepvector Subroutine

    subroutine find_switches_stepvector(csf_i, ind, lower, upper)
        ! same as above but using the already calculated stepvector
        type(CSF_Info_t), intent(in) :: csf_i
        integer, intent(in) :: ind
        integer, intent(out) :: lower, upper
        character(*), parameter :: this_routine = "find_switches_stepvector"

        integer :: switch, i
        ! set defaults
        lower = 1
        upper = nSpatOrbs

        if (csf_i%stepvector(ind) == 1) then
            switch = 2

        else if (csf_i%stepvector(ind) == 2) then
            switch = 1

        else
            ! wrong input!
            call stop_all(this_routine, "wrong input! stepvalue /= {1,2}!")
        end if

        do i = ind - 1, 2, -1
            if (csf_i%stepvector(i) == switch) then
                lower = i
                exit
            end if
        end do
        do i = ind + 1, nSpatOrbs - 1
            if (csf_i%stepvector(i) == switch) then
                upper = i
                exit
            end if
        end do

    end subroutine find_switches_stepvector