Basel: MDPI, 2019. — 130 p.
The term “first-principles calculations” is a synonym for the numerical determination of the electronic structure of atoms, molecules, clusters, or materials from ‘first principles’, i.e., without any approximations to the underlying quantum-mechanical equations that govern the behavior of electrons and nuclei in these systems. In principle, these calculations allow us to learn about structural, mechanical, electronic, optical, and many more properties of molecules and materials without having to resort to any empirical or effective models