AB-INITIO MONTE-CARLO - APPLICATION TO LI-8

An ab initio-based Monte Carlo scheme is developed and implemented to investigate structural and thermal properties of lithium clusters. The scheme combines a hybrid Hartree-Fock/density functional electronic s tructure treatment with a Monte Carlo sampling of the nuclear configur ation space. Structural forms (isomers) of the Li(8 )cluster are obtai ned and its thermal properties are analyzed. The analysis is carried o ut in terms of probability distributions of the cluster potential (con figurational) energy, average potential energy and configurational hea t capacity, all considered as a function of the cluster temperature. A n estimate of the temperature characterizing the onset of isomer 'coex istence' in L-8 is given. (C) 1998 Published by Elsevier Science B.V. All rights reserved.