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 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

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.

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.

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.

Long-range behavior of the transition dipole moments of heteronuclear dimers XY (X, Y = Li, Na, K, Rb) based on ab initio calculations

2018 ◽  
Vol 20 (3) ◽  
pp. 1889-1896 ◽  
Author(s):  
E. A. Bormotova ◽  
S. V. Kozlov ◽  
E. A. Pazyuk ◽  
A. V. Stolyarov
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Excited States ◽  
Long Range ◽  
Internuclear Distance ◽  
Electronic Transition ◽  
Dipole Moments ◽  
Transition Dipole ◽  
Transition Dipole Moments

The electronic transition dipole moments between the ground and excited states converging to the lowest three dissociation limits of heteronuclear dimers XY (X, Y = Li, Na, K, Rb) were ab initio calculated and asymptotically analyzed at large internuclear distance.

Theoretical investigation of the electronic structure and spectra of sulfur monoiodide cation, SI+

2020 ◽  
Vol 98 (12) ◽  
pp. 806-813
Author(s):  
Gabriel Fernando de Melo ◽  
Fernando R. Ornellas
Keyword(s):  
Dipole Moment ◽  
Transition Probabilities ◽  
Dipole Moments ◽  
Transition Dipole Moment ◽  
Theoretical Treatment ◽  
Transition Dipole ◽  
Dissociation Energies ◽  
Moment Functions ◽  
High Level ◽  
First Time

A manifold of singlet, triplet, and quintet electronic states of the sulfur monoiodide cation (SI+) correlating with the two lowest-lying dissociation channels is characterized theoretically at a high level of theoretical treatment (SA-CASSCF/MRCI+Q/aug-cc-pV5Z) for the first time. Potential energy curves, also including the effect of spin-orbit couplings, are constructed and the associated spectroscopic parameters and dissociation energies determined. As to the molecular polarity, we computed the dipole moment as a function of the internuclear distance and the associated vibrationally averaged dipole moments. Transition dipole moment functions were also constructed, and transition probabilities, as expressed by the Einstein coefficients for spontaneous emission, were evaluated for selected pairs of states that we identify as more easily accessible to experimental investigation. An analysis of the bonding in this system is also presented. Together with previous studies on neutral and cationic sulfur-monohalides, one has a comprehensive view of this series of molecules.

Optimization of Gaussian-type basis sets for local spin density functional calculations. Part I. Boron through neon, optimization technique and validation

1992 ◽  
Vol 70 (2) ◽  
pp. 560-571 ◽  
Author(s):  
Nathalie Godbout ◽  
Dennis R. Salahub ◽  
Jan Andzelm ◽  
Erich Wimmer
Keyword(s):  
Spin Density ◽  
Density Functional Calculations ◽  
Density Functional ◽  
Dipole Moments ◽  
Optimization Technique ◽  
Basis Sets ◽  
Gaussian Basis Sets ◽  
Dissociation Energies ◽  
Gaussian Type ◽  
Local Spin

Gaussian-type orbital and auxiliary basis sets have been optimized for local spin density functional calculations. This first paper deals with the atoms boron through neon. Subsequent papers will provide a list through xenon. The basis sets have been tested for their ability to give equilibrium geometries, bond dissociation energies, hydrogenation energies, and dipole moments. These results indicate that the present optimization technique yields reliable basis sets for molecular calculations. Keywords: Gaussian basis sets, density functional theory, boron–neon, geometries, energies of reactions.

THE STUDY OF THE PROPERTIES OF THE GROUND- AND LOW-LYING EXCITED STATES OF ASH2, ${\rm ASH}_{2}^{+}$ AND ${\rm ASH}_{2}^{-}$

2013 ◽  
Vol 12 (02) ◽  
pp. 1250115 ◽  
Author(s):  
YANLI HUO ◽  
MEISHAN WANG ◽  
CHUANLU YANG ◽  
HONGFEI WANG ◽  
ZIXIA MA
Keyword(s):  
Excited States ◽  
Dipole Moments ◽  
Electronic States ◽  
Theoretical Data ◽  
Ionization Potentials ◽  
Basis Sets ◽  
Excitation Energies ◽  
Transition Dipole ◽  
Vertical Excitation ◽  
Cluster Configuration

The properties of the ground and excited states of AsH2 , [Formula: see text] and [Formula: see text] have been investigated by using symmetry-adapted-cluster (SAC)/symmetry-adapted-cluster configuration interaction (SAC-CI) method. The geometry of the ground state of AsH2 is optimized at SAC method with different basis sets. The calculated results with cc-pVTZ and cc-pVQZ basis sets are in very good agreement with the experimental and previous theoretical data. The geometry and the properties of eight low-lying electronic excited states of AsH2 are obtained at SAC-CI/cc-pVTZ and SAC-CI/cc-pVQZ level, including geometries, vertical excitation energies, adiabatic excitation energies, transition dipole moments, and oscillation strengths. Employing the same theoretical level as AsH2 , the geometries, adiabatic ionization potentials (AIPs), and vertical ionization potentials (VIPs) of the ground and eight low-lying electronic states of [Formula: see text] are investigated as well as the geometries, vertical detachment energies (VDEs) and adiabatic detachment energies (ADEs) of nine electronic states of [Formula: see text]. Comparing with the available experimental or previous theoretical data, the SAC/SAC-CI/cc-pVTZ and SAC/SAC-CI/cc-pVQZ results are reliable for AsH2 , [Formula: see text] and [Formula: see text]. The predicted results can afford the useful information for one to deeply investigate them from the spectral experiment.

Theoretical calculation of the electronic states with spin–orbit effects of the molecule LiCs

2009 ◽  
Vol 87 (10) ◽  
pp. 1079-1088 ◽  
Author(s):  
N. Elkork ◽  
D. Houalla ◽  
M. Korek
Keyword(s):  
Electronic States ◽  
Basis Sets ◽  
Spectroscopic Constants ◽  
Spin Orbit ◽  
Gaussian Basis Sets ◽  
Orbit Splitting ◽  
Spin Orbit Splitting ◽  
Semi Empirical ◽  
First Time ◽  
Pseudo Potential

The potential energy curves of the molecule LiCs have been calculated for the 55 low-lying electronic states in the Ω-representation. Using an ab initio method the calculation is based on a nonempirical pseudo-potential in the interval 3.0ao≤ R ≤ 40.0ao of the internuclear distance. The spin–orbit effects have been taken into account through a semi-empirical spin–orbit pseudo-potential added to the electrostatic Hamiltonian with Gaussian basis sets for both atoms. The spectroscopic constants have been calculated for 39 states and the components of the spin–orbit splitting have been identified for the states (2, 5)3Π and (1)3Δ. The comparison of the present results with those available in literature shows good agreement, while the other results, to the best of our knowledge, are given here for the first time.

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