apply_inversion Function

    function apply_inversion(in_orbs) result(out_orbs)
        ! apply inversion through the k-point
        integer, intent(in) :: in_orbs(nBasis / 2)
        integer :: out_orbs(nBasis / 2)

        integer :: i

        if (.not. t_symmetry_inversion) then
            out_orbs = in_orbs
            return
        end if

        do i = 1, nBasis / 2
            out_orbs(i) = inversion(in_orbs(i))
        end do

    end function apply_inversion