P3 Test Results

The P3 approximation to the self-energy was applied to the atoms Li through Kr and to neutral and ionic molecular species from the G2 set [47]. For the atoms, a set of 22 representative basis sets was tested. Results for the molecular set were obtained using standard Pople basis sets as described below. 

Calculations of ionization energies and electron affinities were performed with a modified development version of Gaussian 99 [48], Pople and Effective Core Potential (ECP) basis sets are provided in this software [49], Dunning and Atomic Natural Orbital (ANO) basis sets were obtained from the EMSL Gaussian Basis Set Library [50], 

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