Theoretical study with rovibrational and electronic transitionmoment calculation of the ion LiCs+

2006 ◽  
Vol 84 (11) ◽  
pp. 959-971 ◽  
Author(s):  
M Korek ◽  
A M Moghrabi ◽  
A R Allouche ◽  
M Aubert Frécon
Keyword(s):  
Internuclear Distance ◽  
Bound States ◽  
Dipole Moments ◽  
Basis Sets ◽  
Spectroscopic Constants ◽  
Gaussian Basis Sets ◽  
Transition Dipole ◽  
Vibrational Levels ◽  
Moment Functions ◽  
Dependent Polarization

For the molecular ion LiCs+ the potential energy are calculated for the 39 lowest molecular states of symmetries 2Σ+, 2Π, 2Δ, and Ω = 1/2, 3/2, 5/2. Using an ab initio method, the calculation is based on nonempirical pseudopotentials and parameterized [Formula: see text]-dependent polarization potentials. Gaussian basis sets are used for both atoms and spin-orbit effects are taken into account. The spectroscopic constants for 20 states are calculated by fitting the calculated energy values to a polynomial in terms of the internuclear distance r. Through the canonical functions approach, the eigenvalue Ev, the abscissas of the corresponding turning points (rmin and rmax), and the rotational constants Bv are calculated for up to 44 vibrational levels for four bound states. Using the same approach the dipole moment functions, the corresponding matrix elements, and the transition dipole moments are calculated for the bound states (1)2Σ+, (2)2Σ+, and (1)2Π. The comparison of the present results with those available in literature for the ground state shows a very good agreement. Extensive tables of energy values versus internuclear distance are displayed at the following address: http://lasim.univ-lyon1.fr/allouche/licsso.html.PACS Nos.: 31.15.Ar, 31.25.–v, 31.25.Nj

Systematic trends in electronic properties of alkali hydridesThis article is part of a Special Issue on Spectroscopy at the University of New Brunswick in honour of Colan Linton and Ron Lees.

2009 ◽  
Vol 87 (5) ◽  
pp. 543-556 ◽  
Author(s):  
Mireille Aymar ◽  
Johannes Deiglmayr ◽  
Olivier Dulieu
Keyword(s):  
Electronic Properties ◽  
Internuclear Distance ◽  
Dipole Moments ◽  
Basis Sets ◽  
Gaussian Basis Sets ◽  
Transition Dipole ◽  
Mixed Alkali ◽  
Dipolar Molecules ◽  
The University ◽  
First Time

Obtaining ultracold samples of dipolar molecules is a current challenge, which requires an accurate knowledge of their electronic properties to guide the ongoing experiments. Alkali hydride molecules have permanent dipole moments significantly larger than those of mixed alkali species, and, as pointed out by Taylor-Juarros et al. (Eur. Phys. J. D, 31, 213 (2004)) and by Juarros et al. (Phys. Rev. A, 73, 041403 (2006)), are thus good candidates for cold molecule formation. In this paper, using a standard quantum chemistry approach based on pseudopotentials for atomic core representation, large Gaussian basis sets, and effective core polarization potential, we systematically investigate the electronic properties of the alkali hydrides LiH to CsH, to discuss general trends of their behavior. We computed (for the first time for NaH, KH, RbH, and CsH) the variation of their static polarizability with the internuclear distance. Moreover, in addition to potential curves, we determine accurate values of permanent and transition dipole moments for ground and excited states depending on the internuclear distance. The electronic properties of all alkali hydrides are compared with one another, in the light of the numerous other data available in the literature. Finally, the influence of the quality of the representation of the hydrogen electronic affinity in the approach on the results is discussed.

Theoretical study with spin-orbit effects and electronic transition moment calculation of the ion NaCs+

2008 ◽  
Vol 86 (8) ◽  
pp. 1015-1022 ◽  
Author(s):  
M Korek ◽  
K Badreddine ◽  
A R Allouche
Keyword(s):  
Internuclear Distance ◽  
Bound States ◽  
Theoretical Study ◽  
Electronic States ◽  
Basis Sets ◽  
Spectroscopic Constants ◽  
Spin Orbit ◽  
Gaussian Basis Sets ◽  
Electronic Transition Moment ◽  
Molecular Ion

A theoretical study was done of the electronic structure of the molecular ion NaCs+. The calculation is based on nonempirical pseudopotentials and parameterized [Formula: see text]-dependent polarization potential. Gaussian basis sets were used for both atoms and spin-orbit effects were taken into account. Potential energy curves were obtained for 56 lowest electronic states for the symmetries 2∑+, 2Π, 2Δ, and Ω of the molecular ion NaCs+. The spectroscopic constants were calculated for 19 electronic states by fitting the calculated energy values to polynomials in terms of the internuclear distance r. Through the canonical functions approach the eigenvalue Ev, the rotational constant Bv and the abscissas of the turning points were calculated up to 52 vibrational levels for 6 bound states. The dipole moment were calculated in the considered range of the internuclear distance r. The comparison of the calculated values to those available in the literature shows a good agreement. PACS Nos.: 31.10.+z, 31.15.Ar, 31.50.Df, 33.15.Mt

Structure and electronic properties of the doubly charged diatomic dications BeX2+ (X = Na, K)

2016 ◽  
Vol 94 (1) ◽  
pp. 1-8 ◽  
Author(s):  
Chedli Ghanmi ◽  
Mohamed Farjallah ◽  
Hamid Berriche ◽  
Abdullah G. Al-Sehemi
Keyword(s):  
Electronic Properties ◽  
Electronic States ◽  
Theoretical Data ◽  
Spectroscopic Properties ◽  
Basis Sets ◽  
Gaussian Basis Sets ◽  
Transition Dipole ◽  
Dependent Polarization ◽  
Avoided Crossings ◽  
Doubly Charged

The structural and electronic properties of the doubly charged diatomic dications BeX2+ (X = Na, K) have been systematically investigated. The ab initio calculations method is based on the use of non-empirical pseudopotentials for the Be2+, Na+, and K+ cores, Gaussian basis sets, and parameterized l-dependent polarization potentials. The potential energy curves and their spectroscopic properties for the low-lying electronic states of 2Σ+, 2Π, and 2Δ symmetries have been determined for the species BeNa2+ and BeK2+ for the first time. Results show, for each diatomic dication, that the ground and the first excited electronic states are repulsive. For both systems, for which no experimental and theoretical data are available, we discuss our results by comparing their potential energies with similar systems. Numerous avoided crossings between electronic states of 2Σ+ and 2Π symmetries have been localized and analyzed. Their existence is related to the interaction between the electronic states and to the charge transfer process between the two ionic structures Be(2+)X and Be(+)X(+). Furthermore, the transition dipole functions from the ground state to the 2-102Σ+ and between neighbor electronic states of 2Σ+ symmetry, revealed many abrupt changes, which are localized at particular distances corresponding to the positions of the avoided crossings.

Theoretical study of the electronic structure of LiCs, NaCs, and KCs molecules

2000 ◽  
Vol 78 (11) ◽  
pp. 977-988 ◽  
Author(s):  
M Korek ◽  
A R Allouche ◽  
K Fakhreddine ◽  
A Chaalan
Keyword(s):  
Internuclear Distance ◽  
Bound States ◽  
Theoretical Study ◽  
Spectroscopic Constants ◽  
Ab Initio Method ◽  
Regular Shape ◽  
Wide Range ◽  
Dependent Polarization ◽  
Configuration Interaction Calculations ◽  
Valence Configuration

The potential energy has been calculated over a wide range of internuclear distance for 28 lowest molecular states of LiCs, 32 lowest states of NaCs, and 30 lowest states of KCs molecules. This calculation is done by using an ab initio method based on nonempirical pseudopotentials, parameterized l-dependent polarization potentials, and full valence configuration interaction calculations. Extensive tables of energy values versus internuclear distance are displayed at the following address http://hplasim2.univ-lyon1.fr/allouche. Molecular spectroscopic constants have been derived for the bound states with regular shape. PACS Nos.: 31.15Ar, 31.25-u

Potential curves and rovibrational energies for electronic states of the molecular ion KCs+

2002 ◽  
Vol 80 (9) ◽  
pp. 1025-1035 ◽  
Author(s):  
M Korek ◽  
A R Allouche ◽  
S N Abdul Al
Keyword(s):  
Internuclear Distance ◽  
Bound States ◽  
Electronic States ◽  
Oscillator Strengths ◽  
Basis Sets ◽  
Spectroscopic Constants ◽  
Spin Orbit ◽  
Molecular Ion ◽  
Wide Range ◽  
Potential Curves

The KCs+ molecular ion potential curves are investigated over a wide range of internuclear distance for electronic states described in a 2Λ(+) representation (neglecting the spin-orbit effect) as well as in an Ω(+) representation (including the spin-orbit effect). This calculation has been done in a one active electron approach by using an ab initio method based on non-empirical pseudopotentials with core-valence effect taken into account through parameterized l-dependent polarization potentials. Gaussian basis sets have been used for both atoms, and spin-orbit effects have been taken into account through a semiempirical spin-orbit pseudopotential. The canonical functions approach is used to do a rovibrational study by calculating the eigenvalues Ev, the rotational constant Bv, the centrifugal distortion constants Dv (up to 106 vibrational levels), and the spectroscopic constants are deduced for six bound states. The permanent and transition dipole moment functions have been derived for transitions between the bound states 2 Σ+ and 2Π as well as the oscillator strengths for the transitions v = 0, 10, 20, and Δ v = 0, 1, 2, ..., 6. To the best of our knowledge neither theoretical nor experimental data are available in the literature for the molecular ion KCs+. Extensive tables of Ev, Bv, Dv, and the energy values versus internuclear distance are displayed at the following address: http://hplasim2.univ-lyon1.fr/allouche/kcsplus.html. PACS Nos.: 33.15Dj, 33.20wr

Adiabatic and quasi-diabatic investigation of the strontium hydride cation SrH+: structure, spectroscopy, and dipole moments

2016 ◽  
Vol 94 (9) ◽  
pp. 791-802 ◽  
Author(s):  
Sana Belayouni ◽  
Chedli Ghanmi ◽  
Hamid Berriche
Keyword(s):  
Potential Energy ◽  
Dipole Moments ◽  
Electronic States ◽  
Basis Sets ◽  
Gaussian Basis Sets ◽  
Transition Dipole ◽  
Avoided Crossing ◽  
Wide Range ◽  
Transition Dipole Moments ◽  
Internuclear Distances

Ab initio investigation has been performed for the strontium hydride cation SrH + using a standard quantum chemistry approach. It is based on the pseudopotentials for atomic core representations, Gaussian basis sets, as well as with full configuration interaction calculations. A diabatisation procedure based on the effective hamiltonian theory and an effective metric is used to produce the quasi-diabatic potential energy. Adiabatic and quasi-diabatic potential energy curves and their spectroscopic parameters for the ground and many excited electronic states of 1,3Σ+, 1,3Π, and 1,3Δ symmetries have been determined. Their predicted accuracy is discussed by comparing our well depths and equilibrium positions with the available experimental and theoretical results. Moreover, we localized and analyzed numerous avoided crossings between the electronic states of 1,3Σ+ and 1,3Π symmetries. The correction of the electron affinity of the H atom is also considered, for the 1–101Σ+ electronic states, to improve the accuracy of the adiabatic potential energies of these states. In addition, we calculated the dipole moments, for a wide range of internuclear distances in both diabatic and quasi-diabatic representations. The adiabatic permanent dipole moments for the 101Σ+ electronic states revealed ionic characters related to electron transfer and yields both SrH(+) and Sr(+)H arrangements. The transition dipole moments between neighbor electronic states revealed many peaks around the avoided crossing positions.

scholarly journals Spectroscopic constants and anharmonic force field of dithioformic acid and its isomers: a theoretical study

2021 ◽  
Author(s):  
Weixiu Pang ◽  
Xiaomin Song ◽  
Yunbin Sun ◽  
Meishan Wang
Keyword(s):  
Force Field ◽  
Dipole Moments ◽  
Molecular Structures ◽  
Basis Sets ◽  
Astronomical Observation ◽  
Spectroscopic Constants ◽  
Fundamental Frequencies ◽  
Correlation Consistent ◽  
Consistent Basis ◽  
Anharmonic Force

Abstract The potential astronomical interest dithioformic acid (trans-HC(=S)SH) exists five isomers and has received considerable attention of astronomical observation in recent years. The different positions of H atoms of five isomers lead to diverse point groups, dipole moments, and spectroscopic constants. The anharmonic force field and spectroscopic constants of them are calculated using CCSD(T) and B3LYP employing correlation consistent basis sets. Molecular structures, dipole moments, rotational constants, and fundamental frequencies of trans-HC(=S)SH are compared with the available experimental data. The B3LYP/Gen=5 and CCSD(T)/Gen=Q results can reproduce them well. Molecular structures, dipole moments, relative energies, spectroscopic constants of cis-HC(=S)SH and dithiohydroxy carbene (DTHC) are also calculated. The new data obtained in this study are expected to guide the future high resolution experimental work and to assist astronomical search for CH2S2.

Accurate spectroscopic calculations on the X2Σ +, A2Π, and 22Σ + electronic states of the BeAr+ cation including spin-orbit coupling

2014 ◽  
Vol 92 (5) ◽  
pp. 397-405 ◽  
Author(s):  
Xiang Hong Niu ◽  
Wen Wen Shan ◽  
Shuai Wang ◽  
De Heng Shi
Keyword(s):  
Transition Probabilities ◽  
Coupling Effect ◽  
Dipole Moments ◽  
Orbit Coupling ◽  
Basis Sets ◽  
Spin Orbit Coupling ◽  
Spin Orbit ◽  
Transition Dipole ◽  
Complete Active Space ◽  
Condon Factors

The complete active space self-consistent field/internally contracted multireference configuration interaction calculations with the correlation-consistent basis sets have been made to characterize all of the states of BeAr+ cation, which are attributed to the first two dissociation channels. The effect on the potential energy curves by Davidson correction, core-valence correlation, and scalar relativistic corrections is included. The spin-orbit coupling effect is taken into account by the state interaction method with the Breit–Pauli Hamiltonian. Our calculations can provide some useful guidelines for the future experimental work of band system 22[Formula: see text]+1/2-X2[Formula: see text]+1/2. For the first time, the transition properties including Franck−Condon factors and transition dipole moments have been derived for all of the Ω states. Some transition probabilities and radiative lifetimes have been estimated.

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