Ab initio calculations of the ground state potential function of the hydroxyl anion by means of the many-body Rayleigh-Schrödinger perturbation theory

1981 ◽  
Vol 46 (11) ◽  
pp. 2595-2599
Author(s):  
Ivan Kozák ◽  
Vladimír Špirko ◽  
Petr Čársky
Keyword(s):  
Perturbation Theory ◽  
Ground State ◽  
Negative Ions ◽  
Spectroscopic Constants ◽  
Many Body ◽  
Hydroxyl Anion ◽  
Wide Range ◽  
State Potential ◽  
The Many ◽  
Schrödinger Perturbation

Many-body Rayleigh-Schrödinger perturbation theory (MB-RSPT) up to third order applied to OH- in the range of interatomic distances from 0.0815 to 0.1175 nm. The energy data obtained are combined with the experimental RKR (ground state) potential of HF, and, a ground state potential of OH- is constructed (over a wide range of internuclear distances) within the framework of the reduced potential curve method. With the use of this potential the corresponding rotation-vibration Schrödinger equation is solved for 16OH-. The computed spectroscopic constants are compared with best reported calculations and available experimental evidence. The comparison indicates that MB-RSPT may be used as an adequate (and convenient) tool for the study of negative ions.

Correlation energy in triplet electronic states. Application of the many-body Rayleigh-Schrödinger perturbation theory in the restricted Roothaan-Hartree-Fock formalism

1981 ◽  
Vol 46 (6) ◽  
pp. 1324-1331 ◽  
Author(s):  
Petr Čársky ◽  
Ivan Hubač
Keyword(s):  
Wave Function ◽  
Perturbation Theory ◽  
Correlation Energy ◽  
Electronic States ◽  
Many Body ◽  
Third Order ◽  
Explicit Formulas ◽  
Hartree Fock ◽  
The Many ◽  
Schrödinger Perturbation

Explicit formulas over orbitals are given for the correlation energy in triplet electronic states of atoms and molecules. The formulas were obtained by means of the diagrammatic many-body Rayleigh-Schrodinger perturbation theory through third order assuming a single determinant restricted Roothaan-Hartree-Fock wave function. A numerical example is presented for the NH molecule.

scholarly journals Entangling Lattice-Trapped Bosons with a Free Impurity: Impact on Stationary and Dynamical Properties

Entropy ◽  
2021 ◽  
Vol 23 (3) ◽  
pp. 290
Author(s):  
Maxim Pyzh ◽  
Kevin Keiler ◽  
Simeon I. Mistakidis ◽  
Peter Schmelcher
Keyword(s):  
Structural Changes ◽  
Many Body ◽  
Wide Range ◽  
Entropy Measures ◽  
Particle Level ◽  
The Many ◽  
The One ◽  
Tunneling Dynamics ◽  
The Individual ◽  
Trapped Bosons

We address the interplay of few lattice trapped bosons interacting with an impurity atom in a box potential. For the ground state, a classification is performed based on the fidelity allowing to quantify the susceptibility of the composite system to structural changes due to the intercomponent coupling. We analyze the overall response at the many-body level and contrast it to the single-particle level. By inspecting different entropy measures we capture the degree of entanglement and intraspecies correlations for a wide range of intra- and intercomponent interactions and lattice depths. We also spatially resolve the imprint of the entanglement on the one- and two-body density distributions showcasing that it accelerates the phase separation process or acts against spatial localization for repulsive and attractive intercomponent interactions, respectively. The many-body effects on the tunneling dynamics of the individual components, resulting from their counterflow, are also discussed. The tunneling period of the impurity is very sensitive to the value of the impurity-medium coupling due to its effective dressing by the few-body medium. Our work provides implications for engineering localized structures in correlated impurity settings using species selective optical potentials.

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.

The potential model treatment of the scattering of electrons by atoms and the existence of negative ions

1961 ◽  
Vol 16 (5) ◽  
pp. 492-500
Author(s):  
F. B. Malik ◽  
E. Trefftz
Keyword(s):  
Bound States ◽  
Negative Ions ◽  
Potential Scattering ◽  
Point Of View ◽  
Neutral Atoms ◽  
Many Body ◽  
Scattered Electron ◽  
Scattered Particle ◽  
Potential Term ◽  
The Many

The low energy scattering of electrons by different neutral atoms has been treated by assuming that the atomic wave functions remain unchanged even at the presence of the scattered particle and by neglecting the exchange between the scattered electron and the bound electrons. The potential term in the differential equation of the scattered particle is exactly the atomic potential of the neutral atom and is approximated by analytical expressions, yielding the potential scattering equation. The variational treatments of Hulthén, Kohn and a related one suggested by Malik, are applied to solve this equation for a Hartree atom with l=0. The scattering by He, C and N is treated explicitly and the results of He indicate that in this way one may get some good result without going into the great complexity of the many body problem. It is further pointed out that the study of scattering by neutral atoms near zero energy under this model may serve as a possible mean to investigate the existence of different negative ions and their number of bound states. It seems from this point of view that He-, C- and N- for this model may exist and have one bound s-state.

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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