Finite-temperature behavior of small silicon and tin clusters: An ab initio molecular dynamics study

The finite-temperature behavior of small silicon and tin clusters Si10, Si15, Si20, Sn10, and Sn20 is studied using isokinetic Born-Oppenheimer molecular dynamics. We find that the low-lying structures for all the clusters are built upon a highly stable tricapped trigonal prism unit which is seen to play a crucial role in the finite-temperature behavior. The thermodynamics of small tin clusters is revisited in light of the recent experiments on tin clusters of sizes 18–21 G. A. Breaux et al., Phys. Rev. B, 71, 07341