Ab initio pseudopotential study of M2As and M2Br (M = Cu, Ag, Au)

Abstract

The equilibrium geometries and the vibration frequencies of M 2As - and M 2Br +(M=Cu,Ag,Au)are calculated at the HF and the MP2 levels with pseudopotentials. The calculated results indicate that the species have a bent structure(C 2v ). The electron correlation corrections on the geometrical structure are investigated at the MP2 level, the bond angles are reduced by 10°～20° for considered species. The electron correlation effects on the geometry of the Au 2As - are studied particularly at MP2, MP3, MP4, CCSD and CCSD(T) levels. Comparing the species containing Ag and Au, the relativistic effects slightly short the bond lengths of the species. The bonding possibility of the Au 2As - is predicted.