The accuracy of the Faddeev random phase approximation (FRPA) method is tested by evaluating total and ionization energies in the basis-set limit. A set of light atoms up to Ar is considered. Comparisons are made with the results of coupled-cluster singles and doubles (CCSD), with third-order algebraic diagrammatic construction [ADC(3)], and with the experiment. It is seen that even for two-electron systems, He and Be2 +, the inclusion of RPA effects leads to satisfactory results, and therefore it does not overcorrelate the ground state. The FRPA becomes progressively better for larger atomic numbers, where it gives ≈5 mH more correlation energy, and it shifts ionization potentials by 2-10 mH with respect to the similar ADC(3) method. The ionization potentials from FRPA tend to reduce the discrepancies with the experiment.
Accuracy of the Faddeev random phase approximation for light atoms / C. Barbieri, D. Van Neck, M. Degroote. - In: PHYSICAL REVIEW A. - ISSN 1050-2947. - 85:1(2012), pp. 012501.1-012501.8.
|Titolo:||Accuracy of the Faddeev random phase approximation for light atoms|
|Parole Chiave:||state correlation energies; hartree-fock calculations; particle greens-function; quadrupole-moments; ground-state; ionization energies; propagator approach; excited-states; electron; GW|
|Settore Scientifico Disciplinare:||Settore FIS/03 - Fisica della Materia|
|Data di pubblicazione:||2012|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1103/PhysRevA.85.012501|
|Appare nelle tipologie:||01 - Articolo su periodico|