A geminal theory based on the generalized electron pairing.

J Chem Phys

Department of Molecular Engineering, Graduate School of Engineering, Kyoto University, Kyoto 615-8510, Japan.

Published: June 2023

As in the hierarchy of the Hartree-Fock theory in terms of spin symmetry, the extension of spin functions in a theory of two-electron units or geminal, was developed in this study. A trial wave function is constructed as an antisymmetrized product of geminals, in which singlet and triplet two-electron functions are fully mixed. We present a variational optimization method for this generalized pairing wave function in the strong orthogonality condition. The present method is considered an extension of the antisymmetrized product of strongly orthogonal geminals or perfect pairing generalized valence bond methods, maintaining the compactness of the trial wave function. The obtained broken-symmetry solutions were similar to the unrestricted Hartree-Fock wave functions in terms of spin contamination while giving lower energy due to the inclusion of the electron correlation effect in geminals. The degeneracy of the obtained broken-symmetry solutions in the Sz space is reported for the tested four-electron systems.

Download full-text PDF

Source
http://dx.doi.org/10.1063/5.0152555DOI Listing

Publication Analysis

Top Keywords

wave function
12
terms spin
8
trial wave
8
antisymmetrized product
8
broken-symmetry solutions
8
geminal theory
4
theory based
4
based generalized
4
generalized electron
4
electron pairing
4

Similar Publications

Rapid reduction of body size in populations responding to global warming suggests the involvement of temperature-dependent physiological adjustments during growth, such as mitochondrial alterations, in the efficiency of producing metabolic energy, a process that is poorly explored, especially in endotherms. Here, we examined the mitochondrial metabolism and proteomic profile of red blood cells in relation to body size and cellular energetics in nestling shearwaters (Calonectris diomedea) developing at different natural temperatures. We found that nestlings of warmer nests had lighter bodies and smaller beaks at fledging.

View Article and Find Full Text PDF

Introduction: Increasing evidence links amyloid beta (Aβ) aggregation with inflammation. This pilot study investigated the use of an immunoassay panel to map biomarker changes in patients with Alzheimer's disease (AD). Furthermore, we evaluated the stability of protein quantification after multiple freeze-thaw cycles (FTCs).

View Article and Find Full Text PDF

Background: Elevated blood pressure (BP) in childhood is associated with adult hypertension and arterial stiffness. However, the effect of long-term time in target range (TTR) for BP since childhood on the risk of arterial stiffness in midlife remains unclear.

Objectives: The purpose of this study was to determine the independent association of TTR for systolic blood pressure (SBP) from childhood to midlife with arterial stiffness in adulthood.

View Article and Find Full Text PDF

Objectives: This study aims to investigate whether social networks and physical exercise mediate the relationship between new and constant use of intelligent virtual assistants (IVAs) and cognitive function in older adults in China and explore the potential differences across living arrangements and education levels.

Methods: This study utilized nationally representative longitudinal data from 2018 to 2020, including a sample of 8343 older adults aged 60-80. A path-analytic model was employed to examine the relationship between IVAs use and cognitive function, as well as the mediating roles of social networks and physical exercise.

View Article and Find Full Text PDF

Born-Oppenheimer molecular dynamics (BOMD) simulations are of great interest for the dynamic properties of molecular and solid systems. However, BOMD simulations necessitate not only an extensive period of dynamical evolution but also costly self-consistent-field (SCF) electronic structure calculations, especially for hybrid functional-based BOMD (H-BOMD) simulations within plane-wave basis sets. Here, we propose an improved always stable predictor-corrector (ASPC) method for the wave function extrapolation to accelerate the plane-wave H-BOMD simulations, named projected ASPC (PASPC), yielding a wave function closer to the actual solution space and efficiently reducing the number of SCF iterations at each MD step.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!