Computation of some ionization potentials for second-row elements by ab initio and density functional theory methods

Four ionization potentials of elements from the second row of the periodic table were computed with ab initio (HF, MP2, MP3, MP4, QCISD, G1, G2, and G2MP2) and density functional theory (DFT) (B3LY, B3P86, B3PW91, XALPHA, HFS, HFB, BLYP, BP86, BPW91, BVWN, XAPLY, XAP86, XAPW91, XAVWN, SLYP, SP86, SPW91 and SVWN) methods. In all of the calculations, a large 6-311 + + G(3df, 3pd) Gaussian-type basis set was used. The computed values were compared to experimental results, and the suitability of these ab initio and DTF methods for computing atomic ionization potentials was discussed. It was found that G2 will produce ionization potentials that are indistinguishable from the experimental values. Hybrid B3LYP and nonlocal BLYP will generate very good ionization potentials. For larger atoms, SLYP and SPW91 will compute ionization potentials that are of G2 quality. (C) 1997 John Wiley & Sons, Inc.