Ab initio simulation of Na59+ and Na93+

The electronic structure and melting transition of cationic sodium clusters with 59 and 93 atoms (58 and 92 electrons) have been studied using an ab initio molecular dynamics method. Na59+ and Na93+ are found to undergo a phase transition which can be identified as melting by traditional indicators. Melting transition was observed to start at 175 K and at 160 K in the case of Na59+ and Na93+, respectively. The simulated melting temperature of Na93+ is consistent with experiments. Both Na59+ and Na93+ stay electronically magic through the melting transition. The agreement of the electron density of states of liquid Na59+ and Na93+ with the experimental photoelectron spectra is excellent.