Is it possible to use quantum mechanics to predict chemical bonding?
Yes, it is, and there are two theories describing why this is possible. These theories are valence bond (VB) theory, and molecular orbital (MO) theory.
Valence bond theory explains that the atomic orbitals of the dissociated atoms combine to give individual chemical bonds when a molecule is formed.
Molecular orbital theory determines molecular structure, where the electrons are not assigned to individual bonds between the atoms, but are instead treated as moving under the influence of the nuclei in the whole molecule.
This theory, each molecule has a set of molecular orbitals in which it is assumed that the molecular orbital wave function ψj can be written as a simple weighted sum of the n constituent atomic orbitals,χi, according to the following equation: