2026-08-13 –, Room 2
Efficiently obtaining high-accuracy data for molecules and materials is one of the major challenges in quantum chemistry. We present ElemCo.jl, an efficient, user-friendly, modular, open-source Julia package for performing quantum-chemical calculations, including Hartree-Fock (HF) and post-HF methods, with a focus on Coupled Cluster theory. Particular emphasis will be placed on tensor-decomposed Distinguishable Cluster methods to treat extended systems at substantially reduced computational cost.
Efficiently obtaining high-accuracy data for molecules and materials is one of the major challenges in quantum chemistry. To address this challenge, we present the Julia package ElemCo.jl [1] for performing both established as well as novel electronic structure methods. The program enables mean-field as well as correlation energy calculations, with an emphasis on Coupled and Distinguishable [2] Cluster methods for ground and excited states.
To capture the interest of a broader audience, the talk will be divided into two parts: In the first half, an introduction to the package will be given, including an overview of the program's structure, currently available methods, and compatibility with other quantum-chemical programs.
In the second half, tensor decomposition will be introduced as a tool to substantially reduce the cost of various Distinguishable Cluster methods [3] for extended molecular systems. This is achieved through tensor decomposition of the amplitudes, resulting in a drastic compression of the amplitude space and a reduction in both computational scaling and prefactor, without compromising accuracy. In particular, the decomposition will be applied to DC-CCSDT [4] and EOM-DCSD [5].
[1] GitHub: https://github.com/fkfest/ElemCo.jl and website: https://elem.co.il/
[2] D. Kats and F. R. Manby, J. Chem. Phys. 139, 021102 (2013).
[3] C. Rickert, D. Usvyat and D. Kats, J. Chem. Phys. 163, 064103 (2025).
S. Lambie, C. Rickert, D. Usvyat, A. Alavi and D. Kats, J. Chem. Phys. 163, 111101 (2025).
[4] D. Kats and A. Köhn, J. Chem. Phys. 150, 151101 (2019).
[5] V. Rishi, A. Perera, M. Nooijen, R. Bartlett, J. Chem. Phys. 146, 144104 (2017).
At the moment, I am pursuing a Master's degree in chemistry with a focus on computational and theoretical chemistry at the Humboldt-Universität zu Berlin (HU). Research is my passion: I enjoy developing low-scaling, high-level wavefunction-based methods such as Local or SVD Coupled Cluster for molecules and periodic systems. In this context, I have been actively doing research since 3.5 years at HU and am currently working as a student research assistant at the Max-Planck Institute for Solid State Research.
Scientist at the Max Planck Institute for Solid State Research in the Department for Electronic Structure Theory. Main research area: method development to accurately describe electron correlation in molecules and periodic systems.