含重金属硅化物SiM(M=Au,Ag,Cu)的从头算理论研究

Ab initio theoretic research of SiM(M=Au,Ag,Cu)

在不同电子相关水平上基于相对论和非相对论赝势,对含重金属硅化物SiM(M=Au,Ag,Cu)的基态几何结构和光谱特性进行了研究,并讨论了电子相关效应和相对论效应的影响.结果表明:重金属硅化物SiM(M=Au,Ag,Cu)的基态电子状态是2∏.电子相关效应缩短了金属硅化物的键长,提高了分离能,谐振频率也增加,使SiM(M=Au,Ag,Cu)的结构变得更加紧凑,基态更加稳定.相对论效应加强了它的强度,使三种硅化物更加稳定.相对论作用的顺序为AuSi>AgSi>CuSi.

The geometrical structure and spectroscopic property for the ground state of SiM（M=Au,Ag,Cu）are explored at the different electron correlation methods,using relativistic and non-relativistic pseudo-potentials.Their effects are also discussed.The results show that all silicides are predicted to have the electronic ground state of symmetry,in agreement with earlier theoretical data.The electron correlation effect shorten the bond distances,increase the harmonic frequencies,improve the dissociation energies and make the three silicides trend to more compact and rigidity.The relativistic effects strengthen the intensity,make the molecules more stable.The relativistic effects of the metal silicides follow the sequence SiAu〉SiAg〉SiCu.