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Related papers: Coupled Cluster-Inspired Geminal Wavefunctions

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Composites are ideally suited to achieve desirable multifunctional effective properties since the best properties of different materials can be judiciously combined with designed microstructures. Here we establish cross-property relations…

Soft Condensed Matter · Physics 2020-05-13 Jaeuk Kim , Salvatore Torquato

We discuss diagrammatic modifications to the coupled cluster doubles (CCD) equations, wherein different groups of terms out of rings, ladders, crossed-rings and mosaics can be removed to form approximations to the coupled cluster method, of…

Chemical Physics · Physics 2014-05-06 James J. Shepherd , Thomas. M. Henderson , Gustavo E. Scuseria

We develop a bivariational principle for an antisymmetric product of nonorthogonal geminals. Special cases reduce to the antisymmetric product of strongly-orthogonal geminals (APSG), the generalized valence bond-perfect pairing (GVB-PP),…

A relativistic version of the coupled-cluster single-double (CCSD) method is developed for atoms with a single valence electron. In earlier work, a linearized version of the CCSD method (with extensions to include a dominant class of triple…

Atomic Physics · Physics 2009-11-13 Rupsi Pal , M. S. Safronova , W. R. Johnson , Andrei Derevianko , Sergey G. Porsev

We introduce a method for accurate quantum chemical calculations based on a simple variational wave function, defined by a single geminal that couples all the electrons into singlet pairs, combined with a real space correlation factor. The…

Materials Science · Physics 2009-10-22 M. Marchi , S. Azadi , M. Casula , S. Sorella

Tailored coupled cluster theory represents a computationally inexpensive way to describe static and dynamical electron correlation effects. In this work, we scrutinize the performance of various tailored coupled cluster methods externally…

Chemical Physics · Physics 2021-03-24 Aleksandra Leszczyk , Mihály Máté , Örs Legeza , Katharina Boguslawski

We present a new, non-variational orbital-optimization scheme for the Antisymmetric Product of one-reference orbital Geminal wave function. Our approach is motivated by the observation that an orbital-optimized seniority-zero configuration…

In this perspective, the various measures of electron correlation used in wavefunction theory, density functional theory and quantum information theory are briefly reviewed. We then focus on a more traditional metric based on dominant…

Chemical Physics · Physics 2023-04-07 Róbert Izsák , Aleksei V Ivanov , Nick S. Blunt , Nicole Holzmann , Frank Neese

The dipole moment is a crucial molecular property linked to a molecular system's bond polarity and overall electronic structure. To that end, the electronic dipole moment, which results from the electron density of a system, is often used…

We introduce affordable computational strategies for calculating orbital and pair-orbital energies in atomic and molecular systems. Our methods are based on the pair Coupled Cluster Doubles (pCCD) ansatz and its orbital-optimized variant.…

Chemical Physics · Physics 2025-02-06 Seyedehdelaram Jahani , Somayeh Ahmadkhani , Katharina Boguslawski , Paweł Tecmer

We introduce the electron attachment equation-of-motion pair coupled cluster doubles (EA-EOM-pCCD) ansatz, which allows us to inexpensively compute electron affinities, energies of unoccupied orbitals, and electron attachment spectra. We…

Chemical Physics · Physics 2024-06-24 Marta Gałyńska , Paweł Tecmer , Katharina Bogusławski

As a result of the application of coarse-graining procedures to describe complex fluids, the study of systems consisting of particles interacting through bounded, repulsive pair potentials has become of increasing interest in the last…

Soft Condensed Matter · Physics 2015-05-19 Manuel Camargo , Angel J. Moreno , Christos N. Likos

We show that a simple correlated wave function, obtained by applying a Jastrow correlation term to an Antisymmetrized Geminal Power (AGP), based upon singlet pairs between electrons, is particularly suited for describing the electronic…

Other Condensed Matter · Physics 2009-11-10 M. Casula , C. Attaccalite , S. Sorella

Wavefunctions restricted to electron-pair states are promising models to describe static/nondynamic electron correlation effects encountered, for instance, in bond-dissociation processes and transition-metal and actinide chemistry. To reach…

Chemical Physics · Physics 2017-01-18 Katharina Boguslawski , Paweł Tecmer

We consider a new formulation of the stochastic coupled cluster method in terms of the similarity transformed Hamiltonian. We show that improvement in the granularity with which the wavefunction is represented results in a reduction in the…

Chemical Physics · Physics 2016-02-02 Ruth S. T. Franklin , James S. Spencer , Alberto Zoccante , Alex J. W. Thom

In this paper, we have developed a unitary variant of a double exponential coupled cluster theory, which is capable of mimicking the effects of connected excitations of arbitrarily high rank, using only rank-one and rank-two parametrization…

Chemical Physics · Physics 2022-11-23 Dipanjali Halder , V. S. Prasannaa , Rahul Maitra

Adiabatic mixed quantum/classical molecular dynamics simulations were used to generate snapshots of the hydrated electron (e-) in liquid water at 300 K. Water cluster anions that include two complete solvation shells centered on the e- were…

Data Analysis, Statistics and Probability · Physics 2016-09-28 Ilya A. Shkrob , William J. Glover , Ross E. Larsen , Benjamin J. Schwartz

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

The dual exponential coupled cluster (CC) theory proposed by Tribedi et al.[J. Chem. Theory Comput. 2020, 16, 10, 6317-6328] performs significantly better than the coupled cluster theory with singles and doubles excitations (CCSD) due to…

Computational Physics · Physics 2023-07-26 Anish Chakraborty , Rahul Maitra

The pair-coupled-cluster doubles (pCCD) method has emerged as a viable approach for quantum-chemical studies of strongly correlated systems. Despite its lower formal scaling (O(N$^4$)) compared to other versions of coupled cluster (CC)…

Chemical Physics · Physics 2026-04-17 Rahul Chakraborty , Paweł Tecmer