Browse Abstracts & Presentations - 2021 International Symposium on Molecular Spectroscopy by Subject "Theory and Computation"

• (International Symposium on Molecular Spectroscopy, 2021-06-23)
A three dimensional discrete variable representation (DVR) is developed for the general case of a rare gas atom interacting with an asymmetric top molecule and applied to the case of argon-haloethylene heterodimers. The ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-23)
Vibrational perturbation theory is a commonly-used method for obtaining anharmonic corrections to harmonic zero-order wave functions and energies. The method comes in two main variants, canonical Van Vleck perturbation ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-23)
The vibronic structures of the low-lying electronic states in linear polyatomic molecules, which are utilized to construct closed optical cycling, play crucial roles in the laser-cooling processes. The construction of a ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-23)
The dispersed fluorescence spectrum from the $S_1$ origin of PhCCCN is reported. This molecule, which consists of a cyanoacetylene chain fused to an aromatic phenyl ring, is a potential candidate for astronomical detection. ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-23)
Phosphine is now well established as a biosignature, which has risen to prominence with its recent tentative detection on Venus. To follow up this discovery and related future exoplanet biosignature detections, it is ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-23)
\begin{wrapfigure}{r}{0pt} \includegraphics[scale=0.4]{toc_fin.eps} \end{wrapfigure} Ionic liquids (ILs) are salts with a melting point below 100 ${^\circ}$C and are typically composed of asymmetric organic cations and ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-23)
Diffusion Monte Carlo (DMC) is a technique for obtaining the ground-state solution to the vibrational time-independent Schrödinger equation based on a stochastic sampling of an electronic potential energy surface (PES). ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-23)
The rovibrational energy structure of H$_2$S has been analysed simultaneously for the 20 lowest energy vibrational bands up to J=20. We have used a global analysis rovibrational algebraic approach of which the effective ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-23)
The increasing number and size of large Line-By-Line (LBL)-databases, routinely exceeding hundreds of millions of lines, calls for spectral synthesis algorithms that can process these large number of lines efficiently. In ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-23)
There are long running problems over the precise transition intensities and line positions for ozone\footnote{M. A. H. Smith, V. M. Devi \& D. C. Benner, "The quest for ozone intensities in the 9--11 $\mu$m region: a ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-23)
Based on the the Coriolis interaction conceived by Teller and Tisza (1932), the fundamental Wilson-Howard Hamiltonian (WHH), formulated in 1936\footnote{Wilson, Jr., E. B. \& Howard, J. B. 1936 J. Chem. Phys. 4, 260}, ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-23)
\begin{wrapfigure}{l}{0pt} \includegraphics[scale=0.1]{Band70empirical.eps} \end{wrapfigure} The rotational distributions of the intensities in the low-v vibrational bands are nearly insensitive to the specific forms of ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-23)
Density functional theory (DFT) has become a popular method for computational work involving larger molecular systems as it provides accuracy that rivals ab initio methods while lowering computational cost. Nevertheless, ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-23)
%\begin{wrapfigure}{l}{3cm} %\includegraphics[scale=0.2]{Sergey_03.eps} %\end{wrapfigure} Non-adiabatic couplings (NACs) or derivative couplings (DDRs) between nearly degenerate states can be significant or even divergent. ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-23)
Molecular bending spectra can be broadly categorized into three physical cases, depending on the molecular equilibrium configuration: linear, bent, and nonrigid. We have studied the three cases in detail with an extended ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-23)
In ab initio calculations of diatomic spectroscopy, discrete points are typically computed along the potential energy curve. The points are fitted to a continuous function, such as a polynomial, a Morse function, or a ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-23)
The fundamental Ritz combination principle [1] originally found for atoms has also been applied to molecules as a method to reconstruct the energy states from measured lines without relying on any model Hamiltonian. In ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-23)
Chlorine oxides, namely chlorine monoxide (ClO) and its head-to-tail dimer (ClOOCl), are thought to be important participants in the catalytic destruction of ozone in the Antarctic polar vortex. Chlorine peroxide photolysis ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-23)
\begin{wrapfigure}{l}{0pt} \includegraphics[width=2.2in]{Pic_ISMS.eps} \end{wrapfigure} High-throughput quantum chemical calculations, especially those based on Kohn-Sham density functional theory (KS-DFT), have achieved ...

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• (International Symposium on Molecular Spectroscopy, 2021-06-23)
Benchmark scalar-relativistic delta-coupled-cluster calculations of hetero-site double core ionization energies of small molecules containing second-row elements are presented. This study has focused on high-spin triplet ...

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