STUDY THE STABLE STRUCTURES OF ScGe6 BY GA-DFT AND THE CO ADSORPTION ON ScGe6− CLUSTER

Abstract

The structures of ScGe₆ and ScGe₆⁻ clusters were investigated by a combination of genetic algorithm with quantum chemical calculations (GA-DFT and DLPNO-CCSD(T)). Results show that the two most stable isomers of the ScGe₆ cluster have a pentagonal bipyramid structure with a Sc atom at the vertex and a Ge atom capping the face of tetragonal bipyramid with a Sc atom at the vertex with C_s symmetry. The pentagonal bipyramid with the scandium atom at the vertex with C_5v symmetry is the most stable ScGe₆⁻ cluster. The CO adsorption on the most stable isomer of the anionic cluster was studied by PBE functional. The isomer A1 of ScGe₆⁻ cluster can adsorb CO molecule as well. The most stable structure has CO along with the Sc-Ge bond. In two adsorption models at the Sc atom along the main axis, the Sc-CO adsorption model is more favorable than the Sc-OC model.