Assessing the accuracy of tailored coupled cluster methods corrected by electronic wave functions of polynomial cost

A Leszczyk, M Máté, O Legeza… - Journal of Chemical …, 2021 - ACS Publications
Tailored coupled cluster theory represents a computationally inexpensive way to describe
static and dynamical electron correlation effects. In this work, we scrutinize the performance …

Reference energies for cyclobutadiene: Automerization and excited states

E Monino, M Boggio-Pasqua, A Scemama… - The Journal of …, 2022 - ACS Publications
Cyclobutadiene is a well-known playground for theoretical chemists and is particularly
suitable to test ground-and excited-state methods. Indeed, due to its high spatial symmetry …

[HTML][HTML] Rank-reduced coupled-cluster. III. Tensor hypercontraction of the doubles amplitudes

EG Hohenstein, BS Fales, RM Parrish… - The Journal of Chemical …, 2022 - pubs.aip.org
We develop a quartic-scaling implementation of coupled-cluster singles and doubles
(CCSD) based on low-rank tensor hypercontraction (THC) factorizations of both the electron …

Is externally corrected coupled cluster always better than the underlying truncated configuration interaction?

I Magoulas, K Gururangan, P Piecuch… - Journal of Chemical …, 2021 - ACS Publications
The short answer to the question in the title is “no”. We identify classes of truncated
configuration interaction (CI) wave functions for which the externally corrected coupled …

[HTML][HTML] High-level coupled-cluster energetics by merging moment expansions with selected configuration interaction

K Gururangan, JE Deustua, J Shen… - The Journal of Chemical …, 2021 - pubs.aip.org
Inspired by our earlier semi-stochastic work aimed at converging high-level coupled-cluster
(CC) energetics [JE Deustua, J. Shen, and P. Piecuch, Phys. Rev. Lett. 119, 223003 (2017) …

Hilbert space multireference coupled cluster tailored by matrix product states

O Demel, J Brandejs, J Lang, J Brabec… - The Journal of …, 2023 - pubs.aip.org
In the past decade, the quantum chemical version of the density matrix renormalization
group method has established itself as the method of choice for strongly correlated …

Potential energy curves for F2, Cl2, and Br2 with the i-DMFT method

D Liu, B Yan, M Irimia, J Wang - The Journal of Chemical Physics, 2024 - pubs.aip.org
The potential energy curves for dihalogens (F 2, Cl 2, and Br 2) are calculated with the i-
DMFT method proposed recently [Wang and Baerends, Phys. Rev. Lett. 128, 013001]. All …

Converging high-level coupled-cluster energetics via adaptive selection of excitation manifolds driven by moment expansions

K Gururangan, P Piecuch - The Journal of Chemical Physics, 2023 - pubs.aip.org
ABSTRACT A novel approach to rapidly converging high-level coupled-cluster (CC)
energetics in an automated fashion is proposed. The key idea is an adaptive selection of …

Benchmarking the semi-stochastic CC (P; Q) approach for singlet–triplet gaps in biradicals

A Chakraborty, SH Yuwono, JE Deustua… - The Journal of …, 2022 - pubs.aip.org
We recently proposed a semi-stochastic approach to converging high-level coupled-cluster
(CC) energetics, such as those obtained in the CC calculations with singles, doubles, and …

[HTML][HTML] Finite-temperature many-body perturbation theory for electrons: Algebraic recursive definitions, second-quantized derivation, linked-diagram theorem, general …

S Hirata - The Journal of Chemical Physics, 2021 - pubs.aip.org
A comprehensive and detailed account is presented for the finite-temperature many-body
perturbation theory for electrons that expands in power series all thermodynamic functions …