NECI: N-Electron Configuration Interaction with emphasis on state-of-the-art stochastic methods
Abstract
We present NECI, a state-of-the-art implementation of the Full Configuration Interaction Quantum Monte Carlo algorithm, a method based on a stochastic application of the Hamiltonian matrix on a sparse sampling of the wave function. The program utilizes a very powerful parallelization and scales efficiently to more than 24000 CPU cores. In this paper, we describe the core functionalities of NECI and recent developments. This includes the capabilities to calculate ground and excited state energies, properties via the one- and two-body reduced density matrices, as well as spectral and Green's functions for ab initio and model systems. A number of enhancements of the bare FCIQMC algorithm are available within NECI, allowing to use a partially deterministic formulation of the algorithm, working in a spin-adapted basis or supporting transcorrelated Hamiltonians. NECI supports the FCIDUMP file format for integrals, supplying a convenient interface to numerous quantum chemistry programs and it is licensed under GPL-3.0.
Keywords
Cite
@article{arxiv.2006.14956,
title = {NECI: N-Electron Configuration Interaction with emphasis on state-of-the-art stochastic methods},
author = {Kai Guther and Robert J. Anderson and Nick S. Blunt and Nikolay A. Bogdanov and Deidre Cleland and Nike Dattani and Werner Dobrautz and Khaldoon Ghanem and Peter Jeszenski and Niklas Liebermann and Giovanni Li Manni and Alexander Y. Lozovoi and Hongjun Luo and Dongxia Ma and Florian Merz and Catherine Overy and Markus Rampp and Pradipta K. Samanta and Lauretta R. Schwarz and James J. Shepherd and Simon D. Smart and Eugenio Vitale and Oskar Weser and George H. Booth and Ali Alavi},
journal= {arXiv preprint arXiv:2006.14956},
year = {2020}
}
Comments
68 pages, 8 figures. To be published in the Journal of Chemical Physics, full supplementary files are to be published together with the article