Xiaogong Jing

An ab initio study of M2Te (M = Cu, Ag, Au) systems

Abstract The equilibrium geometries and the vibrational frequencies of M 2 Te (M=Cu,Ag,Au) systems were calculated at HF, second- to fourth-order Moller–Plesset perturbation theory (MP2, MP3, MP4), and coupled cluster methods (CCSD, CCSD(T)) levels, and using relativistic and non-relativistic pseudopotentials for Au 2 Te. The calculated geometries indicated that the species has a bent structure of about 70° angle. Electron correlation corrections on the bond angle are very significant, in general, angles M–Te–M are reduced from 90° to 70°, and on the bond length are small. The property of the electron correlation is analyzed, it seems to be explained in terms of a tangential force. Relativistic effects significantly shorten the bond length of Au 2 Te. Comparing Au 2 Te with Cu 2 Te and Ag 2 Te, it could be predicted that the Au 2 Te is relatively stable.

Ab initio study of small coinage metal telluride clusters AunTem (n, m = 1, 2)

The geometries of the most stable isomers of gold telluride systems AuTe, Au2Te, and AuTe2 are determined using the MP2 method. The aspect of gold—telluride interaction, the electron correlation, and relativistic effects on geometry and stability are investigated at the MP2 and CCSD(T) theoretical levels. The results show that the electron correlation and relativistic effects are responsible not only for gold—gold attraction but also for additional gold—telluride interaction. The gold—telluride interaction is strong enough to modify the known pattern of bare gold clusters. Both effects are essential for determining the geometry and relative stability of this type of systems.

Geometrical and electronic structures of the SnnCl and SnnCl- (n = 1-6) clusters

Theoretical studies of the structures of Sn n Cl and Sn n Cl− (n = 1–6) clusters have been carried out using density functional theory methods. The geometric structure of each unit is optimized at the B3LYP level, employing the LANL2DZpd for tin and DZP++ for chlorine basis sets. The resulting total energies, fragmentation energies and equilibrium geometries of chlorine–tin clusters are presented and discussed, together with natural populations and natural electron configurations. The impact on internal electron transfer between the (Sn n ) subsystem and Cl atom in Sn n Cl− (Sn n Cl) clusters is investigated. In addition, theoretical results for the electron affinities of Sn n Cl (n = 4–6) clusters are in good agreement with experimental results available.

An Ab initio pseudopotential study of MnPo (M = Cu, Ag, Au; n = 1, 2) systems

The small coinage-metal polonium compounds MPo and M2Po, (M = Cu, Ag, Au) are studied at Hartree–Fock (HF), second-order Moller–Plesset perturbation theory (MP2), and coupled cluster method CCSD(T) levels using relativistic and non-relativistic pseudopotentials. The calculated geometries indicate that the M2Po (M = Cu, Ag, Au) systems have bent structures of ~64° angles. Electron correlation corrections to the bond length M–Po are extremely small, but to the bond angle M–Po–M are significant; in general, it was reduced from 86° to 64°. Relativistic effects on bond angle are small, but on bond length are distinct. Both electron correlation effects and relativistic effects are essential to determine the geometry and relative stability of the systems. It can be predicted that Au2Po is relatively stable compared with Ag2Po.