postHartreeFocktekniker
PostHartreeFocktekniker refers to the class of quantum chemical methods that go beyond the Hartree–Fock approximation by including electron correlation explicitly in the many-electron wavefunction. These techniques aim to improve predictions of molecular energies, geometries, and properties by accounting for interactions between electrons that HF neglects. They are generally more computationally intensive and are chosen according to the balance between desired accuracy and system size. The term covers perturbation theory, configuration interaction, coupled cluster, and multireference approaches, among others.
Prominent families include Møller–Plesset perturbation theory (MP2, MP3, MP4), which adds correlation corrections perturbatively and scales
In practice, post-Hartree-Fock techniques are used to obtain accurate thermochemistry, reaction barriers, and spectroscopic constants for