Scandium Atom Interacting with Diatomic Groups

Abstract

With a small number (three) of valence electrons, the Scandium atom shows some typical aspects of the transition-metal chemistry. In this work the chemical bonding of Sc with three representative diatomic groups is studied theoretically. The interaction with CO leads to repulsive, moderately attractive and strongly attractive bondings according to the d¹s², d²s¹ and d³ atomic configurations of Sc respectively. The single radical electron of CN interacts with Sc very similarly as in ScH. The ground state of Sc-CH coming from the two quasi-degenerate states of CH is analyzed. A possible dissociation of H₂ is also shown by calculating the energy balance in a Sc+H₂ approach. A non-empirical HF pseudopotential and a multi-reference single and double CI is used for this purpose. The concepts of the atomic configuration and of the Mulliken population are used upon the natural molecular orbitals to understand the chemical bonding between the Sc atom and the diatomics.