Samarium doped silicon clusters SmSin (n = 3–10) and their anions: Structures, thermochemistry, electron affinities, and magnetic moments

Abstract

The structures, adiabatic electron affinities (AEAs), dissociation energies (DEs), hardness, and magnetic moments of SmSin (n=3–10) and their anions were examined by means of B2PLYP, TPSSh, PBE0 and B3LYP methods. Basis sets adopted are of segmented (SEG) Gaussian valence basis sets and relativistic small-core effective potentials (ECP) with additional diffuse 2dfg functions, denoted aug-SEG/ECP for Sm atoms and aug-cc-pVTZ for Si atoms. The most stable structures can be viewed as replacing a Si of the ground-state structure of Sin+1 with a Sm atom. The theoretical AEAs are in excellent agreement with experimental data, especially the AEAs at B2PLYP and TPSSh levels. The average absolute errors from experiment are by 0.04, 0.06, 0.10 and 0.11eV at the B2PLYP, the TPSSh, the PBE0 and the B3LYP levels, respectively. The DEs of Sm from SmSin (n=3–10) and their anions were estimated to examine their relative stabilities. Natural population analysis (NPA) reveals that the Sm atom in all the neutral and anionic clusters acts as an electron donor. Hardness analysis reveals that doping Sm atom to Sin (n=3–10) clusters raises the photochemical sensitivity. Analysis of magnetic moments reveals that the total magnetic moments are contributed by Samarium atom.