It is based on quantum mechanics and the random phase approximation.

This is what is meant by the random phase approximation.

However, in combination with other methods such as the random phase approximation (RPA) model, the dynamic response of systems may also be studied.

Perturbation theory at the level of the random phase approximation captures many of the properties of composite fermions.

Mean-field theory and extensions (e.g. Hartree-Fock, Random phase approximation)

The random phase approximation (RPA) is an approximation method in condensed matter physics and in nuclear physics.

He and Murray Gell-Mann collaborated to show that the random phase approximation (RPA) can be derived by summing a series of Feynman diagrams.

It implements the RPA (random phase approximation), the TDLDA or ALDA (adiabatic local-density approximation) plus other non-local approximations, including or neglecting local-field effects.

The basic methodology is density functional theory (DFT), but the code also allows use of post-DFT corrections such as hybrid functionals mixing DFT and Hartree-Fock exchange, many-body perturbation theory (the GW method) and dynamical electronic correlations within the random phase approximation.