The unified description of nuclear structure and nuclear reaction aspects allows to calculate, in a consistent manner, the spectroscopic values of the nucleus that is treated as an open quantum system. The E_k, \Gamma_k follow from the energy dependent eigenvalues E_k - i/2 \Gamma_k of the effective Hamiltonian  H describing the nucleus embedded in the continuum of decay channels. The coupling matrix elements \gamma _kc between the resonance states k and the decay channels c are calculated by means of the eigenfunctions of  H. They are complex and energy dependent. The S matrix contains the E_k,  \Gamma_k and \gamma _kc. The R matrix can therefore be generalized in a natural manner by replacing the standard spectroscopic parameters E_k^R, \Gamma_k^R and \gamma _kc^R by the energy dependent functions  E_k,  \Gamma _k and  \gamma _kc. This new version of R matrix allows the extraction of spectroscopic information also from nuclear reactions near decay thresholds and in the regime of high level density where narrow resonances appear together with broad ones. Surface effects play a role similar as in the standard theory.

PACS numbers: 21.30.-x, 24.30.-v, 32.80.Bx, 66.35.+a