Theoretical study of the structural and electronic properties of SimGen and SimGen- (s = m + n <or= 7) clusters.
Ground-state structures, vibrational frequencies, HOMO-LUMO energy gap, electron affinities, and cluster mixing energy of binary semiconductor clusters SimGen in the range s = m + n <or= 7 have been investigated using the B3LYP-DFT and CCSD(T) methods with the basis of 6-311+G(d). SimGen clusters are found to have similar structural patterns and the same spin multiplicities as those of corresponding elemental clusters of Sis and Ges but with more isomeric structures and lower symmetries. Notable structural changes induced by the additional electron were observed, except for s = 4. The mixing energies of binary clusters are negative, which suggests that the mixed clusters are more stable than pure Si and Ge clusters. Both the HOMO-LUMO gaps and the calculated mixing energy show that binary clusters SiGe2, Si2Ge2, Si2Ge3, Si2Ge4, and Si2Ge5 are species with high stability and more likely to be produced experimentally.
Bing
Dan
D
Nguyen
Quoc Chinh
QC
Fan
Xiao-feng
XF
Kuo
Jer-Lai
JL