Lowest-energy structures and electronic properties of Na-Si binary clusters from ab initio global search.

TLDR: The ground state structures of neutral and anionic clusters of Na(n)Si(m) have been determined using genetic algorithm incorporated in first principles total energy code and it is found that the lowest-energy structures of Na-Na clusters resemble those of the pure Si clusters.

Abstract: The ground state structures of neutral and anionic clusters of NanSim (1 ≤ n ≤ 3, 1 ≤ m ≤ 11) have been determined using genetic algorithm incorporated in first principles total energy code. The size dependence of the structural and electronic properties is discussed in detail. It is found that the lowest-energy structures of NanSim clusters resemble those of the pure Si clusters. Interestingly, Na atoms in neutral NanSim clusters are usually well separated by the Sim skeleton, whereas Na atoms can form Na-Na bonds in some anionic clusters. The ionization potentials, adiabatic electron affinities, and photoelectron spectra are also calculated and the results compare well with the experimental data.