English
Related papers

Related papers: N-Representability Violations in Truncated Equatio…

200 papers

Parametric two-electron reduced-density-matrix (p-2RDM) methods have enjoyed much success in recent years; the methods have been shown to exhibit accuracies greater than coupled cluster with single and double substitutions (CCSD) for both…

Chemical Physics · Physics 2010-09-02 A. Eugene DePrince , David A. Mazziotti

The accurate computation of excited states remains a challenge in electronic structure theory, especially for systems with a ground state that requires a multireference treatment. In this work, we introduce a novel equation-of-motion (EOM)…

Chemical Physics · Physics 2025-05-28 Shuhang Li , Zijun Zhao , Francesco A. Evangelista

We present ab initio absorption spectra of six three-dimensional semiconductors and insulators calculated using Gaussian-based periodic equation-of-motion coupled-cluster theory with single and double excitations (EOM-CCSD). The spectra are…

Chemical Physics · Physics 2021-07-13 Xiao Wang , Timothy C. Berkelbach

We discuss the analytic and diagrammatic structure of ionization potential (IP) and electron affinity (EA) equation-of-motion coupled-cluster (EOM-CC) theory, in order to put it on equal footing with the prevalent $GW$ approximation. The…

Chemical Physics · Physics 2019-04-16 Malte F. Lange , Timothy C. Berkelbach

It is virtually impossible to directly solve the Schr\"odinger equation for a many-electron wave function due to the exponential growth in degrees of freedom with increasing particle number. The two-body reduced density matrix (2-RDM)…

Quantum Physics · Physics 2022-04-22 Nicholas Cox

Equation of state (EOS) of pure neutron matter (PNM) is studied in QCD sum rules (QCDSR). It is found that the QCDSR results on EOS of PNM are in good agreement with predictions by current advanced microscopic many-body theories. Moreover,…

Nuclear Theory · Physics 2018-05-30 Bao-Jun Cai , Lie-Wen Chen

The impact of residual electron correlation beyond the equation-of-motion coupled-cluster singles and doubles approximation (EOM-CCSD) on positions and widths of electronic resonances is investigated. To establish a method that accomplishes…

Chemical Physics · Physics 2018-02-14 Thomas-C. Jagau

In many of the approximate functionals in one-body reduced density matrix (1RDM) functional theory, the approximate two-body reduced density matrix (2RDM) in the natural orbital representation only depends on the natural occupation numbers.…

Chemical Physics · Physics 2020-11-24 Klaas J. H. Giesbertz

We consider an electronic bound state of the usual, non-relativistic, molecular Hamiltonian with Coulomb interactions, fixed nuclei, and N electrons (N>1). Near appropriate electronic collisions, we prove that the (N-1)-particle electronic…

Mathematical Physics · Physics 2024-11-22 Thierry Jecko , Camille Noûs

A combined density and first-order reduced-density-matrix (1RDM) functional method is proposed for the calculation of potential energy curves (PECs) of molecular multibond dissociation. Its 1RDM functional part, a pair density functional,…

Chemical Physics · Physics 2020-09-23 Robert van Meer , Oleg Gritsenko , Jeng-Da Chai

The time-dependent equation-of-motion coupled cluster (TD-EOM-CC) and time-dependent coupled cluster (TDCC) methods are compared by simulating Rabi oscillations for different numbers of non-interacting atoms in a classical electromagnetic…

Chemical Physics · Physics 2023-10-02 Andreas S. Skeidsvoll , Henrik Koch

The ground X1{\Sigma}+ state potential energy curve (PEC) and dipole moment curve (DMC) of CO molecule have been revisited within the framework of the relativistic coupled-cluster approach, which incorporates non-perturbative single,…

Quantum algorithms for molecular electronic structure have been developed with lower computational scaling than their classical counterparts, but emerging quantum hardware is far from being capable of the coherence,connectivity and gate…

Quantum Physics · Physics 2020-04-17 Scott E. Smart , David A. Mazziotti

The N-representability problem for reduced density matrices remains a fundamental challenge in electronic structure theory. Following our previous work that employs a unitary-evolution algorithm based on an adaptive derivative-assembled…

In the CP violating supersymmetric extension of the standard model with local gauged baryon and lepton symmetries(BLMSSM), there are new CP violating sources which can give new contributions to the quark electric dipole moment (EDM).…

High Energy Physics - Phenomenology · Physics 2017-03-08 Shu-Min Zhao , Tai-Fu Feng , Zhong-Jun Yang , Hai-Bin Zhang , Xing-Xing Dong , Tao-Guo

Many electronic structure methods rely on the minimization of the energy of the system with respect to the one-body reduced density matrix (1-RDM). To formulate a minimization algorithm, the 1-RDM is often expressed in terms of its…

Chemical Physics · Physics 2025-04-18 Nicolas Cartier , Klaas Giesbertz

Wavefunctions restricted to electron pair states are promising models for strongly-correlated systems. Specifically, the pair Coupled Cluster Doubles (pCCD) ansatz allows us to accurately describe bond dissociation processes and…

Strongly Correlated Electrons · Physics 2019-05-01 Katharina Boguslawski

Time-dependent equation-of-motion coupled cluster (TD-EOM-CC) is used to simulate impulsive stimulated x-ray Raman scattering (ISXRS) of ultrashort laser pulses by neon, carbon monoxide, pyrrole, and p-aminophenol. The TD-EOM-CC equations…

Chemical Physics · Physics 2023-10-10 Alice Balbi , Andreas S. Skeidsvoll , Henrik Koch

We introduce a new equation-of-motion coupled-cluster method based on a pair coupled-cluster doubles (pCCD) reference, termed frozen-pair EOM-CCSD (EOM-fpCCSD). This approach combines the computational efficiency of the pCCD ansatz with a…

Chemical Physics · Physics 2026-05-06 Katharina Boguslawski , Paweł Tecmer

We present the expansion to the expectation value coupled cluster theory (XCC) to the wavefunctions that include the inter electronic distances $r_{12}$ explicitly. We have extended our algebraic manipulation code \paldus to deal with the…

Chemical Physics · Physics 2023-04-25 Aleksandra M. Tucholska , Marcin Modrzejewski , Robert Moszynski