Abinit

ABINIT is an impressive software package that offers essential tools for calculating the energy, charge density, and electronic structure of systems comprising electrons and nuclei, including molecules and periodic solids. The main program, built on Density Functional Theory (DFT), comes with pseudopotentials and planewave basis to streamline the process. One of ABINIT's notable features is the ability to optimize geometry based on DFT forces and stresses, or perform molecular dynamics simulations using these forces.

ABINIT software also has the tools necessary to produce dynamical matrices, Born effective charges, and dielectric tensors. Besides, it can calculate excited states using Time-Dependent Density Functional Theory (for molecules) or Many-Body Perturbation Theory (the GW approximation).

The software boasts several utility programs to supplement the main ABINIT code. ABINIT is an incredibly dynamic software package designed to cater to a variety of users' needs.