CHM 114 Lecture Notes - Lecture 25: Linear Combination Of Atomic Orbitals, Alkali Metal, Bond Order
Document Summary
One of the most efficient approaches used to calculate molecular orbitals is to mathematically express the molecular orbitals as a linear combination of atomic orbitals (lcao). This is a reasonable concept since in the dissociated atom limit the electrons will reside in atomic orbitals. As a general rule for the lcao method, if n atomic orbitals are used as a mathematical basis set, then only n molecular orbitals can be derived. For example, to describe the electronic molecular orbitals of the h2 molecule, the simplest. Lcao approach would be to describe these mo"s as a linear combination for the 1s atomic orbitals centered on each h atomic center. Bond order of 0 does not bond. For the alkali and alkaline earth diatomics, we will assume that the core electrons will remain in core states in the molecule. The valence electrons will occupy mo"s derived from the lcao of the valence ns atomic orbitals.
