NECI

NECI implements the full configuration interaction quantum Monte Carlo method, a particularly efficient formulation of the full configuration interaction, which simulates molecular systems containing tens of electrons and obtains their properties with chemical accuracy, including energy spectra, density matrices, reaction pathways, etc

MPI-FKF, Stuttgart; University of Cambridge; King’s College London

NECI implements the full configuration interaction quantum Monte Carlo method, a particularly efficient formulation of the full configuration interaction, which simulates molecular systems containing tens of electrons and obtains their properties with chemical accuracy, including energy spectra, density matrices, reaction pathways, etc.  NECI uses standard four-body integrals produced codes such as PySCF, Molpro, MolCAS, or VASP.  The code is available under the GNU GPLv3 license, uses the HDF5 library for efficient input/output, and is parallelized with MPI, showing near-perfect scaling to tens of thousands of CPU cores.

Audience

Quantum chemistry; materials science; biochemistry

Current Stage and Next Step

Production-level scientific computing project with improvements in constant development. Exploring and implementing more efficient ways of describing electronic correlation is part of our TREX efforts.