Accurate quantum chemical calculation of the relative energetics of C20 carbon clusters via localized multireference perturbation calculations

We present the first correlated ab initio calculations on isomers of C-20 clusters with accurate basis sets using pseudospectral methods. These calculations are in quantitative agreement with the quantum Monte Carlo results and disagree strongly with density functional results. (C) 1998 Elsevier Science B.V. All rights reserved.