save_eigenspectrum_rsp Module Procedure

        module subroutine save_eigenspectrum_rsp(lambda, residuals, fname)
            !! Saves the eigenspectrum and corresponding residuals to disk use the `npy` binary format.
            implicit none(type, external)
            real(sp), intent(in) :: lambda(:)
            !! Eigenalues.
            real(sp), intent(in) :: residuals(:)
            !! Residual of the corresponding Ritz eigenpairs.
            character(len=*), intent(in) :: fname
            !! Name of the output file.
        end subroutine save_eigenspectrum_rsp