Block2: A comprehensive open source framework to develop and apply state-of-the-art DMRG algorithms in electronic structure and beyond

H Zhai, HR Larsson, S Lee, ZH Cui, T Zhu… - The Journal of …, 2023 - pubs.aip.org
block2 is an open source framework to implement and perform density matrix
renormalization group and matrix product state algorithms. Out-of-the-box it supports the …

Density matrix renormalization group for transcorrelated Hamiltonians: Ground and excited states in molecules

K Liao, H Zhai, EMC Christlmaier… - Journal of Chemical …, 2023 - ACS Publications
We present the theory of a density matrix renormalization group (DMRG) algorithm which
can solve for both the ground and excited states of non-Hermitian transcorrelated …

Tailored and externally corrected coupled cluster with quantum inputs

M Scheurer, GLR Anselmetti, O Oumarou… - Journal of Chemical …, 2024 - ACS Publications
We propose to use wave function overlaps obtained from a quantum computer as inputs for
the classical split-amplitude techniques, tailored and externally corrected coupled cluster, to …

[HTML][HTML] Rationale for the extrapolation procedure in selected configuration interaction

HGA Burton, PF Loos - The Journal of Chemical Physics, 2024 - pubs.aip.org
Selected configuration interaction (SCI) methods have emerged as state-of-the-art
methodologies for achieving high accuracy and generating benchmark reference data for …

[HTML][HTML] Variational coupled cluster for ground and excited states

A Marie, F Kossoski, PF Loos - The Journal of Chemical Physics, 2021 - pubs.aip.org
In single-reference coupled-cluster (CC) methods, one has to solve a set of non-linear
polynomial equations in order to determine the so-called amplitudes that are then used to …

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 …

Hierarchy configuration interaction: Combining seniority number and excitation degree

F Kossoski, Y Damour, PF Loos - The journal of physical chemistry …, 2022 - ACS Publications
We propose a novel partitioning of the Hilbert space, hierarchy configuration interaction
(hCI), where the excitation degree (with respect to a given reference determinant) and the …

Complete active space iterative coupled cluster theory

R Feldmann, M Mörchen, J Lang… - The Journal of …, 2024 - ACS Publications
In this work, we investigate the possibility of improving multireference-driven coupled cluster
(CC) approaches with an algorithm that iteratively combines complete active space (CAS) …

Accurate full configuration interaction correlation energy estimates for five-and six-membered rings

Y Damour, M Véril, F Kossoski, M Caffarel… - The Journal of …, 2021 - pubs.aip.org
Following our recent work on the benzene molecule [P.-F. Loos, Y. Damour, and A.
Scemama, J. Chem. Phys. 153, 176101 (2020)], motivated by the blind challenge of Eriksen …

Externally corrected ccsd with renormalized perturbative triples (R-ecCCSD (T)) and the density matrix renormalization group and selected configuration interaction …

S Lee, H Zhai, S Sharma, CJ Umrigar… - Journal of Chemical …, 2021 - ACS Publications
We investigate the renormalized perturbative triples correction together with the externally
corrected coupled-cluster singles and doubles (ecCCSD) method. We use the density matrix …