scholarly journals A variational calculation of vibrational levels of vinyl radical

2020 ◽  
Vol 152 (20) ◽  
pp. 204311
Author(s):  
Xiao-Gang Wang ◽  
Tucker Carrington
Keyword(s):  
Variational Calculation ◽  
Vibrational Levels ◽  
Vinyl Radical

New simultaneous fit of 12CD4 transitions in the 0–2400 cm−1 region

2017 ◽  
Vol 95 (4) ◽  
pp. 412-422 ◽  
Author(s):  
Okkacha Ouardi ◽  
Mohamed Meskine ◽  
Abdelkrim Karrour
Keyword(s):  
Global Analysis ◽  
Experimental Spectrum ◽  
Variational Calculation ◽  
Calculated Spectrum ◽  
Effective Hamiltonian ◽  
Vibrational Levels ◽  
Least Squares Adjustment ◽  
Rovibrational Spectra ◽  
Tetrahedral Molecules ◽  
Line Positions

We report the global analysis of 12CD4 line positions from high-resolution rovibrational spectra, including accurate lines in the region 0–2400 cm−1. In addition to the lines of P0–P0 and P1–P1 (where P0 is the ground state (GS), and P1 is the dyad (ν2, ν4)), this region covers two cold polyads: P1 (900–1220 cm−1, two vibrational levels, two sublevels) and the pentad (2ν4, ν2 + ν4, ν1, 2ν2, ν3) or P2 (1850–2400 cm−1, five vibrational levels, nine sublevels). In this analysis, 2724 assignments from four sources are fitted using an effective Hamiltonian expanded up to the sixth order for the pentad. For the assignments and analysis, we use the SPVIEW and XTDS software programs that implement the tensorial formalism developed in the Dijon group for tetrahedral molecules. Among the 454 parameters of the effective Hamiltonian for the pentad (of which 10 are relative to the GS (or P0) and 72 are relative to the dyad), 233 were fitted (10 of which are GS and 37 of which are dyad). The 47 parameters for the dyad and the 233 parameters for the pentad allow very good simulations to be made. For this study, a total of 2724 line positions were used in the least squares adjustment characterized by the following global root mean square deviations dRMS for line positions: 0.01 × 10−4 cm−1 for P0–P0, 0.4 × 10−4 cm−1 for P1–P1, 1.3 × 10−4 cm−1 for the dyad, and 0.7 × 10−4 cm−1 for the pentad. XTDS and SPVIEW, which can simulate spectra, allowed us to verify and compare the calculated spectrum, to the experimental spectrum for the dyad and pentad regions of 12CD4 and to a spectrum obtained from variational calculation and from ab initio DMS (TheoReTS information system http://theorets.univ-reims.fr or http://theorets.tsu.ru ).

Convergence Properties of Quasiclassical Trajectory Calculations on Dynamics of Autoionization Event in He(23S)-D2 Penning Ionization

1997 ◽  
Vol 62 (2) ◽  
pp. 154-171 ◽  
Author(s):  
Jan Vojtík ◽  
Richard Kotal
Keyword(s):  
Branching Ratios ◽  
Classical Trajectory ◽  
Vibrational States ◽  
Penning Ionization ◽  
Trajectory Calculations ◽  
Quantum Mechanical Treatment ◽  
Total Ionization ◽  
Vibrational Levels ◽  
Degree Of Convergence ◽  
Product Branching

An analysis of the degree of convergence of theoretical pictures of the dynamics of the autoionization event He(23S)-D2(v" = 0) -> [He...D2+(v')] + e is presented for a number of batches of Monte Carlo calculations differing in the number of the trajectories run. The treatment of the dynamics consists in 2D classical trajectory calculations based on static characteristics which include a quantum mechanical treatment of the perturbed D2(v" = 0) and D2+(v') vibrational motion. The vibrational populations are dynamical averages over the local widths of the He(23S)-D2(v" = 0) state with respect to autoionization to D2+(...He) in its v'th vibrational level and the Penning electron energies are related to the local differences between the energies of the corresponding perturbed D2(v" = 0)(...He*) and D2+(v')(...He) vibrational states. Special attention is paid to the connection between the requirements on the degree of convergence of the classical trajectory picture of the event and the purpose of the calculations. Information is obtained regarding a scale of the trajectory calculations required for physically sensible applications of the model to an interpretation of different type of experiments on the system: total ionization cross section measurements, Penning ionization electron spectra, subsequent 3D classical trajectory calculations of branching ratios of the products of the postionization collision process, and interpretation of electron ion coincidence measurements of the product branching ratios for individual vibrational levels of the nascent Penning ion.

Energies and Electric Dipole Moments of the Bound Vibrational States of HN2+ and DN2+

2008 ◽  
Vol 73 (6-7) ◽  
pp. 873-897 ◽  
Author(s):  
Vladimír Špirko ◽  
Ota Bludský ◽  
Wolfgang P. Kraemer
Keyword(s):  
Dipole Moment ◽  
Nearest Neighbor ◽  
Energy Surface ◽  
Dipole Moments ◽  
Three Dimensional ◽  
Vibrational States ◽  
Spacing Distribution ◽  
Triatomic Molecules ◽  
Vibrational Levels ◽  
Different Levels

The adiabatic three-dimensional potential energy surface and the corresponding dipole moment surface describing the ground electronic state of HN2+ (Χ1Σ+) are calculated at different levels of ab initio theory. The calculations cover the entire bound part of the potential up to its lowest dissociation channel including the isomerization barrier. Energies of all bound vibrational and low-lying ro-vibrational levels are determined in a fully variational procedure using the Suttcliffe-Tennyson Hamiltonian for triatomic molecules. They are in close agreement with the available experimental numbers. From the dipole moment function effective dipoles and transition moments are obtained for all the calculated vibrational and ro-vibrational states. Statistical tools such as the density of states or the nearest-neighbor level spacing distribution (NNSD) are applied to describe and analyse general patterns and characteristics of the energy and dipole results calculated for the massively large number of states of the strongly bound HN2+ ion and its deuterated isotopomer.

scholarly journals Bichromatic Photoassociation Spectroscopy for the Determination of Rotational Constants of Cs2 0 u + Long-Range State below the 6S1/2 + 6P1/2 Asymptote

Molecules ◽  
2020 ◽  
Vol 25 (17) ◽  
pp. 3963
Author(s):  
Jizhou Wu ◽  
Jie Ma ◽  
Yuqing Li ◽  
Wenliang Liu ◽  
Peng Li ◽  
...  
Keyword(s):  
Long Range ◽  
Spectroscopic Technique ◽  
Rigid Rotor ◽  
Simple Analysis ◽  
Rotational Constants ◽  
Vibrational Levels ◽  
Photoassociation Spectroscopy ◽  
Rotor Model ◽  
Good Agreement

This article demonstrates new observation of the high-resolution ro-vibrational bichromatic photoassociation spectra (BPAS) of Cs2 in the 0u+ long-range state below the asymptotes 6S1/2 + 6P1/2. By combining with a modulation spectroscopic technique, precise references of the frequency differences have been engineered through the BPAS, with which the rotational constants of low-lying vibrational levels of the Cs20u+ long-range state have been accurately determined by fitting the frequency differences to the non-rigid-rotor model. The rotational constants for the newly observed seven ro-vibrational levels are summarized and disagreement for the level ῦ = 498 is clarified. The rotational constants of different vibrational levels demonstrate strong perturbations of the related energy structures. A simple analysis is performed and shows good agreement with experimental results.

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