scholarly journals All-order calculations of the energy levels of heavy elements Indium (In) and Tin (Sn)

2019 ◽  
Vol 14 (9) ◽  
pp. 34
Author(s):  
Dinh Thi Hanh
Keyword(s):  
Energy Levels ◽  
Potential Method ◽  
Heavy Elements ◽  
Many Body ◽  
Interaction Technique ◽  
Hartree Fock ◽  
Valence Electrons ◽  
Many Body Perturbation Theory ◽  
The Many ◽  
Good Agreement

The energy levels of the heavy elements In, Sn+ and Sn are presented in this article. Dominating corrections beyond the relativistic Hartree-Fock method are included to all orders in the Coulomb interaction using the Feynman diagram technique and the correlation potential method. The configuration interaction technique is combined with the many-body perturbation theory to construct the many-electron wave function for valence electrons and to include core-valence correlations. The good agreement of the results of our calculation with experiment data illustrates the power of the method.

scholarly journals THE METHOD OF INCREMENTS — A WAVEFUNCTION-BASED AB-INITIO CORRELATION METHOD FOR SOLIDS

2007 ◽  
Vol 21 (13n14) ◽  
pp. 2204-2214 ◽  
Author(s):  
BEATE PAULUS
Keyword(s):  
Experimental Data ◽  
Ab Initio ◽  
Ground State ◽  
Infinite System ◽  
Correlation Energy ◽  
Correlation Method ◽  
Many Body ◽  
Hartree Fock ◽  
The Many ◽  
Good Agreement

The method of increments is a wavefunction-based ab initio correlation method for solids, which explicitly calculates the many-body wavefunction of the system. After a Hartree-Fock treatment of the infinite system the correlation energy of the solid is expanded in terms of localised orbitals or of a group of localised orbitals. The method of increments has been applied to a great variety of materials with a band gap, but in this paper the extension to metals is described. The application to solid mercury is presented, where we achieve very good agreement of the calculated ground-state properties with the experimental data.

scholarly journals Calculation of Francium Hyperfine Anomaly

Atoms ◽  
2018 ◽  
Vol 6 (3) ◽  
pp. 39 ◽  
Author(s):  
Elena Konovalova ◽  
Yuriy Demidov ◽  
Mikhail Kozlov ◽  
Anatoly Barzakh
Keyword(s):  
Hyperfine Structure ◽  
Principal Quantum Number ◽  
Many Body ◽  
Experimental Accuracy ◽  
Hartree Fock ◽  
Many Body Perturbation Theory ◽  
Structure Constants ◽  
Analytical Expressions ◽  
Weakly Dependent ◽  
Good Agreement

The Dirac–Hartree–Fock plus many-body perturbation theory (DHF + MBPT) method has been used to calculate hyperfine structure constants for Fr. Calculated hyperfine structure anomaly for hydrogen-like ion is in good agreement with analytical expressions. It has been shown that the ratio of the anomalies for s and p1/2 states is weakly dependent on the principal quantum number. Finally, we estimate Bohr–Weisskopf corrections for several Fr isotopes. Our results may be used to improve experimental accuracy for the nuclear g factors of short-lived isotopes.

scholarly journals Calculation of the hyperfine structure of the superheavy elements E113 and E114+

2019 ◽  
Vol 15 (3) ◽  
pp. 5
Author(s):  
Dinh Thi Hanh
Keyword(s):  
Hyperfine Structure ◽  
Superheavy Elements ◽  
Many Body ◽  
Core Polarization ◽  
Hartree Fock ◽  
The Core ◽  
Many Body Perturbation Theory ◽  
Structure Constants ◽  
The Many ◽  
Qed Effects

The hyperfine-structure constants of the lowest s and p1/2 states of superheavy elements E113 and E114+ are presented in this article. The relativistic Hartree-Fock method with the core polarization being taken into account by means of the many-body perturbation theory. Breit and quantum electrodynamic (QED) effects are also considered. Similar calculations for Tl and Pb+ are used to gauge the accuracy of the calculations.

scholarly journals Hartree–Fock many-body perturbation theory for nuclear ground-states

2016 ◽  
Vol 756 ◽  
pp. 283-288 ◽  
Author(s):  
Alexander Tichai ◽  
Joachim Langhammer ◽  
Sven Binder ◽  
Robert Roth
Keyword(s):  
Perturbation Theory ◽  
Ground States ◽  
Many Body ◽  
Hartree Fock ◽  
Many Body Perturbation Theory

scholarly journals Psi4 1.4: Open-Source Software for High-Throughput Quantum Chemistry

2020 ◽  
Author(s):  
Daniel Smith ◽  
Lori Burns ◽  
Andrew Simmonett ◽  
Robert Parrish ◽  
Matthew Schieber ◽  
...  
Keyword(s):  
Perturbation Theory ◽  
Quantum Chemistry ◽  
Open Source ◽  
Density Functional ◽  
Many Body ◽  
Hartree Fock ◽  
Large Numbers ◽  
Many Body Perturbation Theory ◽  
Infrastructure Project ◽  
Job Specification

<div> <div> <div> <p>Psi4 is a free and open-source ab initio electronic structure program providing Hartree–Fock, density functional theory, many-body perturbation theory, configuration interaction, density cumulant theory, symmetry-adapted perturbation theory, and coupled-cluster theory. Most of the methods are quite efficient thanks to density fitting and multi-core parallelism. The program is a hybrid of C++ and Python, and calculations may be run with very simple text files or using the Python API, facilitating post-processing and complex workflows; method developers also have access to most of Psi4’s core functionality via Python. Job specification may be passed using The Molecular Sciences Software Institute (MolSSI) QCSchema data format, facilitating interoperability. A rewrite of our top-level computation driver, and concomitant adoption of the MolSSI QCArchive Infrastructure project, make the latest version of Psi4 well suited to distributed computation of large numbers of independent tasks. The project has fostered the development of independent software components that may be reused in other quantum chemistry programs. </p> </div> </div> </div>

scholarly journals Surface chemistry effects on work function, ionization potential and electronic affinity of Si(100), Ge(100) surfaces and SiGe heterostructures

2020 ◽  
Vol 22 (44) ◽  
pp. 25593-25605
Author(s):  
Ivan Marri ◽  
Michele Amato ◽  
Matteo Bertocchi ◽  
Andrea Ferretti ◽  
Daniele Varsano ◽  
...  
Keyword(s):  
Perturbation Theory ◽  
Surface Chemistry ◽  
Work Function ◽  
Ionization Potential ◽  
Many Body ◽  
Many Body Perturbation Theory ◽  
The Many ◽  
Electronic Affinity

Surface chemistry effects are calculated within the many body perturbation theory for Si(100), Ge(100) and SiGe surfaces.

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