Theoretical investigation of LaC 3 n + ( n = 0, 1, 2) clusters by density functional theory

LaC 3 n + ( n =0, 1, 2) clusters have been studied using B3LYP (Becke 3‐parameter–Lee‐Yang‐Parr) density functional method. The basis set is Dunning/Huzinaga valence double zeta for carbon and [2 s 2 p 2 d ] for lanthanum, denoted LANL1DZ. Four isomers are presented for each cluster; two of them are edge binding isomers with C 2 v symmetry, the other two are linear chains with C ∞ v symmetry. Meanwhile, two spin states for each isomer, that is, singlet and triplet for LaC 3 + , doublet and quartet for LaC 3 and LaC 3 2+ , respectively, are also considered. Geometries, vibrational frequencies, infrared intensities, and other quantities are reported and discussed. The results indicate that at some spin states; the C 2 v symmetry isomers are the dominant structures, while for the other spin states, linear isomers are energetically favored. © 1998 John Wiley & Sons, Inc. Int J Quant Chem 66 : 301–307, 1998