Abinitioselfhyphen;consistent field and configuration interaction study of Cu5O and Ag5O as models for oxygen chemisorption on Cu(100) and Ag(100)

摘要

The lowest electronic states of Cu5O and Ag5O arising from interaction of atomic oxygen (3P) and the isolated cluster model on the2Eor4A2electronic states have been studied at the SCF, CASCI, MP2, and CIPSI levels using nonempirical pseudopotentials for the Ar (Kr) cores of Cu (Ag). The ground state of Cu5O and Ag5O is found to be2Ebut only after inclusion of correlation effects. However, the energy difference between2Eand the4A2or2A1electronic states is rather small. The effects of electronic correlation have been analyzed in terms of nondynamical and dynamical contributions. It is shown that SCF values account for only about 25percnt;ndash;30percnt; of the total binding energy, whereas inclusion of nondynamical correlation contributions allow to recover 50percnt; of that value. Thus, dynamical correlation effects must be included in order to describe properly oxygenhyphen;cluster interaction occurring in these systems. Results are in good agreement with recent all electron CI studies carried out for Cu5O (2E).