Density Functional Theory Study on the Structures and Properties of Ge_mSi_n(m=1,2;n=1～7) Clusters

Structures and stabilities of GemSin(m=1,2;n=1~7) clusters have been studied within density functional theory(DFT).Structural optimization and frequency analysis were carried out at the B3LYP/6-311G level.For the most stable isomers of GemSin(m=1,2;n=1~7) clusters,as well as the second-order differences,fragmentation energies and bond properties are analyzed.The results indicate that the geometrical structures of GemSin(m=1,2;n=1~7) clusters are very similar to that of Sis(s=m+n) clusters,the bond properties with similar size of GemSin clusters.This offers an effective way of searching the ground structures of larger GemSin clusters.Charge always transfers from silicon to germanium atoms.Among different GemSin(m=1,2;n=1~7) clusters,GeSi3,GeSi6,Ge2Si2 and Ge2Si5 are the most stable clusters.