free_davidson_ss Subroutine

    subroutine free_davidson_ss(this)

        type(davidson_ss), intent(inout) :: this

        ! we are now done with these arrays
        safe_free(this%basis_vectors)
        safe_free(this%multiplied_basis_vectors)
        safe_free(this%residual)
        safe_free(this%eigenvector_proj)
        ! but keep the davidson eigenvector

    end subroutine free_davidson_ss