Incremental Treatments of the Full Configuration Interaction Problem
Join us for a talk by Associate Professor Janus Juul Eriksen (Technical University of Denmark).
Abstract
I will start by giving a brief account of the various areas of electronic-structure theory that we are focused on within my group @ DTU, before next delving into our work on so-called many-body expanded full configuration interaction (MBE-FCI) theory [1-4].
In MBE-FCI, exact solutions to the electronic Schrödinger equation are approximated by performing a multitude of complete active space CI (CASCI) calculations within successively larger truncated orbital spaces, that is, without recourse to an explicit sampling of the full linear wave function [5]. Among other things, I will present how we can make use of (non-)Abelian point-group symmetries within MBE-FCI to simulate chemical problems of unprecedented size [6,7]. Finally, I will close by discussing some personal reflections on how incremental takes on electronic-structure theory may lend themselves favourable to emerging fault-tolerant quantum computing.
References:
[1]: Eriksen, J. J.; Lipparini, F.; Gauss, J.: Virtual Orbital Many-Body Expansions: A
Possible Route towards the Full Configuration Interaction Limit. J. Phys. Chem. Lett.
8, 4633 (2017)
[2]: Eriksen, J. J.; Gauss, J.: Generalized Many-Body Expanded Full Configuration
Interaction Theory. J. Phys. Chem. Lett. 10, 7910 (2019)
[3]: Eriksen, J. J.; Gauss, J.: Incremental Treatments of the Full Configuration Interaction
Problem. WIREs Comput. Mol. Sci. 11, e1525 (2021)
[4]: Greiner, J.; Gauss, J.; Eriksen, J. J.: Error Control and Automatic Detection of
Reference Active Spaces in Many-Body Expanded Full Configuration Interaction. J.
Phys. Chem. A 128, 6806 (2024)
[5]: Eriksen, J. J.: The Shape of Full Configuration Interaction to Come. J. Phys.
Chem. Lett. 12, 418 (2021)
[6]: Greiner, J.; Eriksen, J. J.: Symmetrization of Localized Molecular Orbitals. J.
Phys. Chem. A 127, 3535 (2023)
[7]: Greiner, J.; Gauss, J.; Eriksen, J. J.: Exploiting Non-Abelian Point-Group Symmetry
to Estimate the Exact Ground-State Correlation Energy of Benzene in a Polarized
Split-Valence Triple-Zeta Basis Set. J. Phys. Chem. Lett. 15, 9881 (2024)
Find the venue
When you enter the building at Lyngbyvej 2, go to the end furthest away from Jagtvej.
At the end of the building you turn right and walk down the hallway until you reach the lift.
Go to the 4th floor and turn left when you leave the lift. You’ll find us at the end of the hallway.