In engineering, the ability to optimize materials properties often requires a deep understanding of the relationship between chemical-atomistic structures and the physical properties of the material itself, even both in its solid and fluid phases. Monte Carlo methods allow for a reliable calculation of thermodynamic properties to better predict chemical and physical properties of materials, which is useful not only for engineering but also for science.

TREX developments target eight different codes belonging to the scientific domain of quantum chemistry, not all of them being exclusively QMC codes: TurboRVB, CHAMP, QMC=Chem, NECI, Quantum Package, GammCor, TREXIO and QMCkl.

TREX Open Access codes are available from the TREX CoE Community on Github



NECI code


NECI implements the full configuration interaction quantum Monte Carlo method, a particularly efficient formulation of the full configuration interaction.

GammCor code


GammCor performs calculations of interaction energies for ground- and excited-state multireference wave functions, and range-separated multiconfiguration DFT energy with the long-range-AC/AC0 correlation correction.

TurboRVB code


TurboRVB is a package for ab initio QMC simulations of both molecular and bulk electronic systems, including electronic structure calculations based on flexible variational wave functions and QMC-driven molecular dynamics simulations for both classical and quantum nuclei.


CHAMP code


The Cornell-Holland Ab-initio Materials Package (CHAMP) is a quantum Monte Carlo package for electronic structure calculations of molecular systems


QMC = Chem

QMC=Chem is a quantum Monte Carlo package for electronic structure calculations of molecular systems.

Quantum Package

Quantum Package

Quantum Package is an electronic structure software focused on wave function methods (configuration interaction) combined with density functional theory.