translate English to French: Structures were fully optimized at the UHF/6-31G* or UHF/STO-3G levels, and some of the calculations on were expanded with single point MP2/6-31G*//UHF/6-31G* computations.
On a optimisé ces structures aux niveaux UHF/6-31G* ou UHF/STO-3G et on a développé certains calculs relatifs au cation radicalaire C4H8+ avec des calculs du point unique MP2/6-31G*/UHF/6-31G.