The geometric structures and stabilities of CuSin (n = 8, 10, 12) clusters
were studied using a hybrid density functional method (B3LYP). Eight isomer
s were found for CuSi8, 21 isomers for CuSi10 and five isomers for CuSi12.
The stabilities of CuSin can be well related to the stabilities of Sin. The
Si frameworks are kept nearly unchanged and Cu is located at a substitutio
nal site in many isomers of CuSin, especially for CuSi10. The obtained resu
lts can be used to understand well the observations in mass spectrometric e
xperiments. The high abundance of CuSi10 in the experimental mass spectrum
is attributed to the enhanced stability of CuSi10 over neighboring clusters
and the existence of a large number of low-lying isomers. (C) 2001 Elsevie
r Science BN. All rights reserved.