scholarly journals Determination of the Optimal Energy Denominator Shift Parameter of KRb Electronic States in Quantum Chemical Computations Using Perturbation Theory

2016 ◽  
Vol 82 (6) ◽  
pp. 901-904 ◽  
Author(s):  
M. B. Shundalau ◽  
A. A. Minko
Keyword(s):  
Perturbation Theory ◽  
Quantum Chemical ◽  
Electronic States ◽  
Shift Parameter ◽  
Optimal Energy ◽  
Quantum Chemical Computations ◽  
Energy Denominator

scholarly journals Ab initio quantum-chemical computations of the absorption cross sections of HgX2 and HgXY (X, Y = Cl, Br, and I): molecules of interest in the Earth's atmosphere

2019 ◽  
Vol 21 (1) ◽  
pp. 455-467 ◽  
Author(s):  
Sebastian P. Sitkiewicz ◽  
Daniel Rivero ◽  
Josep M. Oliva-Enrich ◽  
Alfonso Saiz-Lopez ◽  
Daniel Roca-Sanjuán
Keyword(s):  
Electronic Structure ◽  
Ab Initio ◽  
Cross Sections ◽  
Quantum Chemical ◽  
Electronic States ◽  
Absorption Cross ◽  
Spectrum Range ◽  
Mercury Halides ◽  
Quantum Chemical Computations ◽  
Structure Properties

The electronic-structure properties of the low-lying electronic states and the absorption cross sections of mercury halides have been determined within the UV-vis spectrum range (170 nm ≤ λphoton ≤ 600 nm).

Ab initio quantum–chemical computations of the electronic states in HgBr2 and IBr: Molecules of interest on the Earth’s atmosphere

2016 ◽  
Vol 145 (24) ◽  
pp. 244304 ◽  
Author(s):  
Sebastian P. Sitkiewicz ◽  
Josep M. Oliva ◽  
Juan Z. Dávalos ◽  
Rafael Notario ◽  
Alfonso Saiz–Lopez ◽  
...  
Keyword(s):  
Ab Initio ◽  
Quantum Chemical ◽  
Electronic States ◽  
Earth’S Atmosphere ◽  
Earth's Atmosphere ◽  
Quantum Chemical Computations

Perturbation theory of substituent effect. Importance of the field effect in transmission of the substituent effect

1980 ◽  
Vol 45 (6) ◽  
pp. 1655-1661 ◽  
Author(s):  
Robert Ponec
Keyword(s):  
Perturbation Theory ◽  
Carboxylic Acids ◽  
Quantum Chemical ◽  
Substituent Effect ◽  
Field Effect ◽  
Adequate Description ◽  
Meta Position ◽  
Unsaturated Carboxylic Acids

Various quantum chemical approaches to the problem of transmission of the substituent effect were compared. It was shown that inclusion of the electronic repulsion (field effect) was necessary to give a true picture of differences in ρ constants for reactions of the cis and trans isomers of substituted unsaturated carboxylic acids; the same holds for an adequate description of transmission of the substituent effect from the meta position on a given skeleton.

scholarly journals Determination of α(Mz) from an hyperasymptotic approximation to the energy of a static quark-antiquark pair

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Cesar Ayala ◽  
Xabier Lobregat ◽  
Antonio Pineda
Keyword(s):  
Perturbation Theory ◽  
Energy Range ◽  
Short Distance ◽  
Weak Coupling ◽  
Strong Consistency ◽  
Lattice Data ◽  
Static Potential ◽  
Static Energy ◽  
Static Quark

Abstract We give the hyperasymptotic expansion of the energy of a static quark-antiquark pair with a precision that includes the effects of the subleading renormalon. The terminants associated to the first and second renormalon are incorporated in the analysis when necessary. In particular, we determine the normalization of the leading renormalon of the force and, consequently, of the subleading renormalon of the static potential. We obtain $$ {Z}_3^F $$ Z 3 F (nf = 3) = $$ 2{Z}_3^V $$ 2 Z 3 V (nf = 3) = 0.37(17). The precision we reach in strict perturbation theory is next-to-next-to-next-to-leading logarithmic resummed order both for the static potential and for the force. We find that the resummation of large logarithms and the inclusion of the leading terminants associated to the renormalons are compulsory to get accurate determinations of $$ {\Lambda}_{\overline{\mathrm{MS}}} $$ Λ MS ¯ when fitting to short-distance lattice data of the static energy. We obtain $$ {\Lambda}_{\overline{\mathrm{MS}}}^{\left({n}_f=3\right)} $$ Λ MS ¯ n f = 3 = 338(12) MeV and α(Mz) = 0.1181(9). We have also MS found strong consistency checks that the ultrasoft correction to the static energy can be computed at weak coupling in the energy range we have studied.

scholarly journals Analytical Theory of Attosecond Transient Absorption Spectroscopy of Perturbatively Dressed Systems

2019 ◽  
Vol 9 (7) ◽  
pp. 1350
Author(s):  
Daria Kolbasova ◽  
Robin Santra
Keyword(s):  
Perturbation Theory ◽  
Absorption Spectroscopy ◽  
Transient Absorption ◽  
Electronic States ◽  
Theoretical Description ◽  
Transient Absorption Spectroscopy ◽  
Electron Dynamics ◽  
Optical Pulses ◽  
Absorption Signal ◽  
Level Model

A theoretical description of attosecond transient absorption spectroscopy for temporally and spatially overlapping XUV and optical pulses is developed, explaining the signals one can obtain in such an experiment. To this end, we employ a two-stage approach based on perturbation theory, which allows us to give an analytical expression for the transient absorption signal. We focus on the situation in which the attosecond XUV pulse is used to create a coherent superposition of electronic states. As we explain, the resulting dynamics can be detected in the spectrum of the transmitted XUV pulse by manipulating the electronic wave packet using a carrier-envelope-phase-stabilized optical dressing pulse. In addition to coherent electron dynamics triggered by the attosecond pulse, the transmitted XUV spectrum encodes information on electronic states made accessible by the optical dressing pulse. We illustrate these concepts through calculations performed for a few-level model.

Determination of normal force for optimal energy dissipation of harmonic disturbance in a semi-active device

2008 ◽  
Vol 311 (3-5) ◽  
pp. 633-651 ◽  
Author(s):  
Paulin Buaka Muanke ◽  
Patrice Masson ◽  
Philippe Micheau
Keyword(s):  
Energy Dissipation ◽  
Normal Force ◽  
Active Device ◽  
Optimal Energy

Quantum chemical calculations for the determination of the molecular structure of conjugated compounds

1979 ◽  
Vol 51 ◽  
pp. 99-105 ◽  
Author(s):  
Roland Benedix ◽  
Peter Birner ◽  
Frieder Birnstock ◽  
Horst Hennig ◽  
Hans-Jörg Hofmann
Keyword(s):  
Molecular Structure ◽  
Quantum Chemical Calculations ◽  
Quantum Chemical ◽  
Conjugated Compounds
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