www.eas.org INTERACTION OF CONFIGURATION IN SPECTRAL OPACITY CALCULATIONS FOR STELLAR PHYSICS

Abstract. We discuss the role of Configuration Interaction (CI) and the influence of the number of configurations taken into account in the cal-culations of nickel and iron spectral opacities provided by the OPAC in-ternational collaboration, including statistical approaches (SCO, CASSANDRA, STA), detailed accounting (OPAS, LEDCOP, OP, HULLAC-v9) or hybrid method (SCO-RCG). Opacity calculations are presented for a temperature T of 27.3 eV and a density of 3.4 mg/cm3, conditions relevant for pulsating stellar envelopes. 1 State of the art on Iron opacity comparisons Extensive comparisons of nickel and iron spectral opacity calculations have been performed by the OPAC international collaboration (Turck-Chièze et al. 2011a,b; Gilles et al. 2011). We have considered results obtained with the code