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Related papers: Transition-Potential Coupled Cluster

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Theory of one-electron transition density matrices has been formulated within the time-independent coupled cluster method for the polarization propagator [R. Moszynski, P. S. \.Zuchowski, and B. Jeziorski, Coll. Czech. Chem. Commun. {\bf…

Chemical Physics · Physics 2014-09-25 Aleksandra M. Tucholska , Marcin Modrzejewski , Robert Moszynski

Topological error correction--a novel method to actively correct errors based on cluster states with topological properties--has the highest order of tolerable error rates known to date (10^{-2}). Moreover, the scheme requires only…

Very recently, we have introduced correlation consistent effective core potentials (ccECPs) derived from many-body approaches with the main target being its use in explicitly correlated methods but also in mainstream approaches. The ccECPs…

We present an implementation of equation-of-motion oscillator strengths for the multilevel CCSD (MLCCSD) model where CCS is used as the lower level method (CCS/CCSD). In this model, the double excitations of the cluster operator are…

Chemical Physics · Physics 2020-09-21 Sarai D. Folkestad , Henrik Koch

Implementation of Effective Core Potentials (ECPs) into the molecular scattering suite UKRmol+ is presented together with a set of calculations for a range of targets relevant for plasma modeling. Continuum description in scattering and…

The accuracy at which total energies of open-shell atoms and organic radicals may be calculated is assessed for selected coupled cluster perturbative triples expansions, all of which augment the coupled cluster singles and doubles (CCSD)…

Chemical Physics · Physics 2016-05-17 Janus Juul Eriksen , Devin A. Matthews , Poul Jørgensen , Jürgen Gauss

We present a massive-parallel implementation of the resolution-of-identity (RI) coupled-cluster approach that includes single, double and perturbatively triple excitations, namely RI-CCSD(T), in the FHI-aims package for molecular systems. A…

Computational Physics · Physics 2018-10-19 Tonghao Shen , Igor Ying Zhang , Matthias Scheffler

Multiconfiguration expansions frequently target valence correlation and correlation between valence electrons and the outermost core electrons. Correlation within the core is often neglected. A large orbital basis is needed to saturate both…

Atomic Physics · Physics 2010-04-20 S. Verdebout , P. Jönsson , G. Gaigalas , M. Godefroid , C. Froese Fischer

We present an equation of motion coupled cluster approach for calculating and understanding intrinsic inelastic losses in core level x-ray absorption spectra (XAS). The method is based on a factorization of the transition amplitude in the…

Chemical Physics · Physics 2020-05-20 John J. Rehr , Fernando D. Vila , Joshua J. Kas , Nitzan Y. Hirshberg , Karol Kowalski , Bo Peng

We discuss a variety of many-body approaches, within effective-mass and $\mathbf{k}\cdot\mathbf{p}$ envelope-function formalisms, for calculating correlated single excitons in semiconductor nanocrystals (NCs) to all orders in the…

Mesoscale and Nanoscale Physics · Physics 2022-04-28 S. A. Blundell , C. Guet

Conventional photoemission orbital tomography based on Fourier iterative method enables us to extract a projected two-dimensional (2D) molecular orbital from a 2D photoelectron momentum map (PMM) of planar $\pi$-conjugated molecules in a…

Materials Science · Physics 2024-03-01 Misa Nozaki , Takehisa Konishi

We present the quantum-selected configuration interaction-tailored coupled-cluster (QSCI-TCC) method, a hybrid quantum-classical scheme that tailors coupled-cluster (CC) theory with a quantum-selected configuration interaction (QSCI) wave…

Chemical Physics · Physics 2025-06-23 Luca Erhart , Yuichiro Yoshida , Wataru Mizukami

We analyze the many-particle correlations that affect the optical properties of two-dimensional semiconductors. These correlations manifest themselves through the specific optical resonances such as excitons, trions, etc. Starting from the…

Mesoscale and Nanoscale Physics · Physics 2021-03-24 A. Kudlis , I. Iorsh

The extension of the highly-optimized local natural orbital (LNO) CCSD(T) method is presented for high-spin open-shell molecules. The techniques enabling the outstanding efficiency of the closed-shell LNO-CCSD(T) variant are adopted,…

Chemical Physics · Physics 2023-11-17 P. Bernát Szabó , József Csóka , Mihály Kállay , Péter R. Nagy

Time-resolved spectroscopy provides the main tool for analyzing the dynamics of excitonic energy transfer in light-harvesting complexes. To infer time-scales and effective coupling parameters from experimental data requires to develop…

Chemical Physics · Physics 2018-11-28 Tobias Kramer , Mirta Rodriguez , Yaroslav Zelinskyy

For many-body methods such as MCSCF and CASSCF, in which the number of one-electron orbitals are optimized and independent of basis set used, there are no problems with using plane-wave basis sets. However, for methods currently used in…

Computational Physics · Physics 2020-09-02 Eric J. Bylaska , Duo Song , Nicholas P. Bauman , Karol Kowalski , Daniel Claudino , Travis S. Humble

In the molecular quantum chemistry community, coupled-cluster (CC) methods are well-recognized for their systematic convergence and reliability. The extension of the theory to extended systems has been comparably recent, so that…

Chemical Physics · Physics 2024-10-31 Andreas Grüneis , Evgeny Moerman , Matthias Scheffler , Tonghao Shen , Igor Ying Zhang

We show that electron-hole correlation can be used to tune interband and intraband optical transition rates in semiconductor nanostructures with at least one weakly confined direction. The valence-to-conduction band transition rate can be…

Mesoscale and Nanoscale Physics · Physics 2018-08-24 Josep Planelles , Alexander W. Achtstein , Riccardo Scott , Nina Owschimikow , Juan I. Climente

We present an embedding approach to treat local electron correlation effects in periodic environments. In a single, consistent framework, our plane-wave based scheme embeds a local high-level correlation calculation (here Coupled Cluster…

Chemical Physics · Physics 2021-01-07 Tobias Schäfer , Florian Libisch , Georg Kresse , Andreas Grüneis

The double electron attachment (DEA) and double ionization potential (DIP) equation-of-motion coupled-cluster (EOMCC) methods including up to 4-particle-2-hole (4$p$-2$h$) and 4-hole-2-particle (4$h$-2$p$) excitations on top of…

Chemical Physics · Physics 2026-05-21 Jun Shen , Karthik Gururangan , Piotr Piecuch