STABILITIES OF ISOMERS OF LAC12+ AND LAC13+

Theoretical studies that employ ab initio density functional technique s have been presented for the relative stabilities of isomers of LaC12 + and LaC13+. While LaC12+ exhibits the most stable isomer with La ins erted into the carbon ring, LaC13+ exhibits the most stable structure in which the La atom is inside the ring. Our computations are consiste nt with the recent experimental study on LaCn+ isomers which suggests alternation of fast and slow ring isomers as a function of n.