Heat capacities from Born–Oppenheimer molecular dynamics simulations: [formula omitted] and [formula omitted

Abstract

State-of-the-art first-principle all-electron density functional theory Born–Oppenheimer molecular dynamics simulations on cationic aluminum clusters with 27 and 28 atoms are presented. The cluster heat capacities were calculated from these simulations with the multiple histogram method. The obtained latent heats and heat capacities are compared with available experimental results. In agreement with experiment our study shows a well defined peak in the heat capacity curve for the Al28+ cluster, whereas for the Al27+ a very small broad peak is observed. To the best of our knowledge this is the first all-electron ab initio calculation of thermodynamics properties of small finite systems. The good qualitative and quantitative agreement with experiments underlines the high accuracy of all-electron ab initio Born–Oppenheimer molecular dynamics simulations.