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Papers by Hela HABLI

Computational and Theoretical Chemistry, Aug 1, 2017

An ab initio investigation has been performed for the ground and several excited states of Ca + H... more An ab initio investigation has been performed for the ground and several excited states of Ca + He and CaHe systems. The potential energy curves, spectroscopic constants, vibrational levels energies and electric dipole moments have been calculated and analyzed. The ab initio method uses the pseudo-potentials technique, Core Polarization Potentials (CPP) and Full Configuration Interaction (FCI). The number of active electrons of Ca + He and CaHe are reduced to one and two active electrons, respectively. The examination of these numerous results shows interesting structures and behaviors resulting from a collision-induced process that involves calcium and helium atoms. An excellent agreement is found with the available results which confirms the reliability of our calculation.

Chemical Physics, Jun 1, 2017

Ab initio calculation including Configuration Interaction (CI) approach has been used to carry ou... more Ab initio calculation including Configuration Interaction (CI) approach has been used to carry out the Potential Energy Curves (PECs) and their spectroscopic constants (D e well depth, R e the equilibrium distances, T e transition energies, ω e vibrational constant, ω e χ e anharmonic constant and B e rotational constant) of 51 electronic states for different symmetries Σ + , Π and ∆ of SrK +. The vibrational energies levels and their spacing, the permanent and transition dipole moments (PDM and TDM) have been also investigated. The molecular ion is considered as effective two-electron system. These valence electrons are modeled by a Core Polarization Potential (CPP) and Effective Core Potential (ECP) with l-dependent cutoff functions.

Chemical Physics, May 1, 2012

ABSTRACT For all states dissociating below the ionic limit Li−K+, we perform an adiabatic and dia... more ABSTRACT For all states dissociating below the ionic limit Li−K+, we perform an adiabatic and diabatic study for 1Σ+ electronic states dissociating into K (4s, 4p, 4d, 5s, 5p, 5d, 6s)+Li (2s, 2p, 3s). Furthermore, we present the adiabatic results for the 1–11 3Σ, 1–8 1,3Π and 1–4 1,3Δ states. The present calculations on the KLi molecule are complementary to previous theoretical work on this system, including recently observed electronic states that had not been calculated previously. The calculations rely on an ab initio pseudo-potential, Core Polarization Potential operators for the core–valence correlation and full valence CI approaches, combined to an efficient diabatization procedure. For the low-lying states, our spectroscopic constants and vibrational level spacing are in good agreement with the available experimental data. Diabatic potentials and permanent dipole moments are analyzed, revealing the strong imprint of the ionic state in the 1Σ+ adiabatic states.

Journal of Computational Chemistry, Jun 26, 2013

For all states dissociating below the ionic limit Li− Rb+, we perform a diabatic study for 1Σ+ el... more For all states dissociating below the ionic limit Li− Rb+, we perform a diabatic study for 1Σ+ electronic states dissociating into Rb (5s, 5p, 4d, 6s, 6p, 5d, 7s, 4f) + Li (2s, 2p, 3s). Furthermore, we present the diabatic results for the 1–11 3σ, 1–8 1,3Π, and 1–4 1,3Δ states. The present calculations on the RbLi molecule are complementary to previous theoretical work on this system, including recently observed electronic states that had not been calculated previously. The calculations rely on ab‐initio pseudopotential, core polarization potential operators for the core‐valence correlation and full valence configuration interaction approaches, combined to an efficient diabatization procedure. For the low‐lying states, diabatic potentials and permanent dipole moments are analyzed, revealing the strong imprint of the ionic state in the 1Σ+ adiabatic states. The transition dipole moment is used to evaluate the radiative lifetimes of the vibrational levels trapped in the 2 1Σ+ excited states for the first time. In addition to the bound–bound contribution, the bound–free term has been evaluated using the Franck–Condon approximation and also exactly added to the total radiative lifetime. © 2013 Wiley Periodicals, Inc.

International Journal of Quantum Chemistry, Mar 13, 2014

A wide adiabatic study is performed for NaRb molecule, involving 151Σ+ electronic states includin... more A wide adiabatic study is performed for NaRb molecule, involving 151Σ+ electronic states including the ionic state Na−Rb+, as well as 143Σ+, 1–91,3Π, and 1–51,3Δ states. This investigation is performed using an ab initio approach which involves the effective core potential, the core polarization potential with l‐dependent cut‐off functions. The NaRb system has been treated as a two‐electron system and the full valence configuration interaction is easily achieved. The spectroscopic constants Re, De, Te, ωe, ωexe, Be, and D0 for all these states are derived. We have also computed the vibrational levels as well their spacing for different values of J. In addition, permanent and transition dipole moments are determined and analyzed. The Dunham coefficients have been used to perform experimental spacing to compare directly with our results. The present calculations on NaRb extend previous theoretical works to numerous electronic excited states in the various symmetries. © 2014 Wiley Periodicals, Inc.

Journal of Physical Chemistry A, Nov 14, 2011

The diabatic and adiabatic potential-energy curves and permanent and transition dipole moments of... more The diabatic and adiabatic potential-energy curves and permanent and transition dipole moments of the highly excited states of the CaH(+) molecular ion have been computed as a function of the internuclear distance R for a large and dense grid varying from 2.5 to 240 au. The adiabatic results are determined by an ab initio approach involving a nonempirical pseudopotential for the Ca core, operatorial core-valence correlation, and full valence configuration interaction. The molecule is thus treated as a two-electron system. The diabatic potential energy curves have been calculated using an effective metric combined to the effective Hamiltonian theory. The diabatic potential-energy curves and their permanent dipole moments for the (1)∑(+) symmetry are examined and corroborate the high imprint of the ionic state in the adiabatic representation. Taking the benefit of the diabatization approach, correction of hydrogen electron affinity was taken into account leading to improved results for the adiabatic potentials but also the permanent and transition electric dipole moments.

International Journal of Quantum Chemistry, Nov 13, 2014

ABSTRACT The potentials, spectroscopic properties and electric dipole moments of SrH+ are compute... more ABSTRACT The potentials, spectroscopic properties and electric dipole moments of SrH+ are computed for 63 molecular states dissociating up to Sr2+ + H− using an ab initio approach. The ab initio formalism is based on large basis sets, nonempirical atomic pseudopotential for strontium core, correlation treatment for core valence through the effective core polarization potentials and for valence through full valence configuration interaction. Our theoretical molecular constants match published values very well and a large amount of new results is produced. Unusual potential shapes are found in 1Σ+ states often caused by avoided crossing series between them and imprinted by the ionic state Sr2+H−. The high potential energy curves suggest, it is possible to form H− or at least to neutralize H+ in collisions with strontium. © 2014 Wiley Periodicals, Inc.

Journal of Physics B, Nov 5, 2020

Potential energy curves, spectroscopic parameters, electric dipole moments (PEDM and TEDM) and vi... more Potential energy curves, spectroscopic parameters, electric dipole moments (PEDM and TEDM) and vibrational levels’ spacing for 141Σ+, 133Σ+, 81,3Π, and 31,3Δ electronic states, including the ionic limit K−Cs+, are highly computed and presented in adiabatic representation. These properties are determined by the use of an ab initio method involving non-empirical pseudo-potentials, the core polarization potentials, the l-dependent cut-off functions, and the full valence configuration interaction. An important shape where an ionic state behaving as (−1/R), has been clearly pointed out in the 1Σ+ symmetry. This irregularity has been made due to the ionic charge transfer state (K−Cs+), which induces a series of avoided crossings at intermediate and long internuclear ranges. It is interesting to note that the ionic character linked to the ionic charge transfer K−Cs+ state has been clearly illustrated in the PEDM. The current calculations on the KCs molecule are complementary to the published theoretical works, including recently observed electronic states that had not been calculated previously. For the low-lying electric states, spectroscopic constants, PEDM, as well as TEDM are in good agreement with the available experimental data. The relevant data of the KCs molecule are meaningful and useful in several prospective experiments such as photo-association experiments or the manipulation of ultra-cold molecules.

International Journal of Quantum Chemistry

An extensive diabatic investigation of the NaRb species has been carried out for all excited stat... more An extensive diabatic investigation of the NaRb species has been carried out for all excited states up to the ionic limit Na-Rb 1. An ab initio calculation founded on the pseudopotential, core polarization potential operators and full configuration interaction has been used with an efficient diabatization method involving a combination of variational effective hamiltonian theory and an effective overlap matrix. Diabatic potential energy curves and electric dipole moments (permanent and transition) for all the symmetries R 1 , P, and D have been studied for the first time. Thanks to a unitary rotation matrix, the examination of the diabatic permanent dipole moment (PDM) has shown the ionic feature clearly seen in the diabatic 1 R 1 potential curves and confirming the high imprint of the Na-Rb 1 ionic state in the adiabatic representation. Diabatic transition dipole moments have also been computed. Real crossings have been shown for the diabatic PDM, locating the avoided crossings between the corresponding adiabatic energy curves.

Physica Scripta

A computational study of the electronic structure of the SrKr and Sr+Kr molecular systems is pres... more A computational study of the electronic structure of the SrKr and Sr+Kr molecular systems is presented in this paper. The theoretical approach is based on the pseudo-potential technique for Sr++Kr interaction and core-valence correlation for the one and two electrons-Sr++Kr interaction. The potential energy surfaces (PESs), spectroscopic parameters, electric dipole moments (EDM), and the vibrational levels’ spacing for all electronic states are calculated. The accuracy of the current spectroscopic results is discussed by comparing them to the available experimental and theoretical data. It is interesting to note that several avoided crossings (ACs) have occurred between the high-lying 2Σ+ excited states. Each curve exhibits ionic and neutral branches in the AC region, yielding the appearance of the ionic character and the illustration of charge transfer.

Journal of Molecular Graphics and Modelling

Journal of Quantitative Spectroscopy and Radiative Transfer, 2021

Abstract A non-relativistic description of the electronic structure for the heteronuclear molecul... more Abstract A non-relativistic description of the electronic structure for the heteronuclear molecule KRb was developed through the Full Configuration Interaction (FCI) and pseudo-potential method. Below the ionic limit K−Rb+, the ground and all excited singlet and triplet states of different symmetries Σ+, Π and Δ (in the Hund's case (a): 2s + 1Λ±) were intensively investigated. Several adiabatic results including potential energy curves (PECs), permanent and transition electric dipole moments (PEDM, TEDM) were analyzed in short and long-range of internuclear distances. Tables of these properties as functions of separation are presented. The spectroscopic constants with the vibrational levels were derived using the “Numerov” algorithm. These molecular parameters were compared with those published in the literature, feature a good agreement. In the adiabatic representation, strong couplings between successive 1Σ+ states were reached by series of avoided crossing, yielding to the appearance of the ionic character and the good illustration of charge transfer. This description of the KRb molecule was helpful in the design of the prospect photo-association experiments and the obtaining of the quantum-degenerate gas of the polar molecule.

Journal of Physics B: Atomic, Molecular and Optical Physics, 2020

Potential energy curves, spectroscopic parameters, electric dipole moments (PEDM and TEDM) and vi... more Potential energy curves, spectroscopic parameters, electric dipole moments (PEDM and TEDM) and vibrational levels’ spacing for 141Σ+, 133Σ+, 81,3Π, and 31,3Δ electronic states, including the ionic limit K−Cs+, are highly computed and presented in adiabatic representation. These properties are determined by the use of an ab initio method involving non-empirical pseudo-potentials, the core polarization potentials, the l-dependent cut-off functions, and the full valence configuration interaction. An important shape where an ionic state behaving as (−1/R), has been clearly pointed out in the 1Σ+ symmetry. This irregularity has been made due to the ionic charge transfer state (K−Cs+), which induces a series of avoided crossings at intermediate and long internuclear ranges. It is interesting to note that the ionic character linked to the ionic charge transfer K−Cs+ state has been clearly illustrated in the PEDM. The current calculations on the KCs molecule are complementary to the publish...

Journal of Quantitative Spectroscopy and Radiative Transfer, 2018

This is a PDF file of an unedited manuscript that has been accepted for publication. As a service... more This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Highlights  Electronic energies and dipole moments for the ion CaNa+ are theoretically investigated.  Spectroscopic parameters are derived from potential energy curves.  Vibrational level spacings for selected states are drawn and analyzed.  Numerous avoided crossings are detected in PECs and its reflection in PDM and TDM functions is discussed.

Molecular Physics, 2018

Van der Waals interactions between the valence electrons of the barium atom and the closed-shell ... more Van der Waals interactions between the valence electrons of the barium atom and the closed-shell cores have been studied using ab initio methods with a combination of pseudopotentials and core polarisation potential. We have reported the potential energy curves, the spectroscopic constants, the vibrational levels as well as the electric dipole moments for the ground and several excited states of Ba + Kr and BaKr complexes. Interesting behaviour has been observed in the potential energy curves, particularly for + states. This can show the strong repulsive interactions between Rydberg electrons and the Krypton atom.

Journal of Quantitative Spectroscopy and Radiative Transfer, 2017

This is a PDF file of an unedited manuscript that has been accepted for publication. As a service... more This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Highlights  Investigation the potential energy curves.  Determination the spectroscopic properties.  Investigation the electric dipole moments and vibrationel levels of diatomic molecules.

Molecular Physics, 2016

ABSTRACT The structural and electronic properties of (SrLi)+ molecular ion have been determined b... more ABSTRACT The structural and electronic properties of (SrLi)+ molecular ion have been determined by the use of ab initio approaches. Potential energy curves (PECs) with their spectroscopic constants (Re, De, ωe, Te, Be and ωeχe) have been calculated. Also, the vibrational properties and the electric dipole moments, either permanent (PDM) or transition (TDM) ones, have been investigated and analysed. Large Gaussian basis sets, the full valence configuration interaction (FCI) and the formalism of non-empirical pseudo-potential including the two approaches, effective core potential (ECP) and core polarisation potential (CPP), are analysed. Therefore, (SrLi)+ is considered as a two effective electrons system. Numerous excited states of symmetries 1,3Σ+, 1,3Π and 1,3Δ dissociating below the ionic limit Sr2+Li− have been investigated. This study shows interesting behaviours around the avoided crossing related to charge transfer involving important processes in physics and astrophysics such as dynamics, pre-dissociation and inelastic transitions.

The Journal of Chemical Physics, 2014

The structures and relative stabilities of mixed Ba2+Xen (n = 1–39, 54) clusters have been theore... more The structures and relative stabilities of mixed Ba2+Xen (n = 1–39, 54) clusters have been theoretically studied using basin-hopping global optimization. Analytical potential energy surfaces were constructed from ab initio or experimental data, assuming either purely additive interactions or including many-body polarization effects and the mutual contribution of self-consistent induced dipoles. For both models the stable structures are characterized by the barium cation being coated by a shell of xenon atoms, as expected from simple energetic arguments. Icosahedral packing is dominantly found, the exceptional stability of the icosahedral motif at n = 12 being further manifested at the size n = 32 where the basic icosahedron is surrounded by a dodecahedral cage, and at n = 54 where the transition to multilayer Mackay icosahedra has occurred. Interactions between induced dipoles generally tend to decrease the Xe-Xe binding, leading to different solvation patterns at small sizes but al...

The Journal of Physical Chemistry A, 2013

An adiabatic study of 1-34 1,3 Σ + electronic states of Baruim hydride ion (BaH +) is presented f... more An adiabatic study of 1-34 1,3 Σ + electronic states of Baruim hydride ion (BaH +) is presented for all states dissociating below the ionic limit Ba 2+ H-. The 1-20 Π 3 , 1 and 1-12 ∆ 3 , 1 states have been also investigated. In our approach, the valence electron of Ba 2+ ion is described by an effective core potential (ECP) and core polarization potential (CPP) with l-dependent cutoff functions have been used. The ionic molecule BaH + has been treated as a two-electron system and the full valence configuration interaction (CI) is easily achieved. The spectroscopic constants R e , D e , T e , ω e , ω e x e and B e are derived. In addition, vibrational levels spacing, permanent and transition dipole moments are determined and analyzed. Unusual potentials shapes are found and also accidental quasi degeneracy in the vibrational spacing progression for various excited states. The 1 Σ + states exhibit ionic charge transfer avoided crossings series which could lead to neutralization or even Hformation in collisions of H + with Ba.

Computational and Theoretical Chemistry, Aug 1, 2017

An ab initio investigation has been performed for the ground and several excited states of Ca + H... more An ab initio investigation has been performed for the ground and several excited states of Ca + He and CaHe systems. The potential energy curves, spectroscopic constants, vibrational levels energies and electric dipole moments have been calculated and analyzed. The ab initio method uses the pseudo-potentials technique, Core Polarization Potentials (CPP) and Full Configuration Interaction (FCI). The number of active electrons of Ca + He and CaHe are reduced to one and two active electrons, respectively. The examination of these numerous results shows interesting structures and behaviors resulting from a collision-induced process that involves calcium and helium atoms. An excellent agreement is found with the available results which confirms the reliability of our calculation.

Chemical Physics, Jun 1, 2017

Ab initio calculation including Configuration Interaction (CI) approach has been used to carry ou... more Ab initio calculation including Configuration Interaction (CI) approach has been used to carry out the Potential Energy Curves (PECs) and their spectroscopic constants (D e well depth, R e the equilibrium distances, T e transition energies, ω e vibrational constant, ω e χ e anharmonic constant and B e rotational constant) of 51 electronic states for different symmetries Σ + , Π and ∆ of SrK +. The vibrational energies levels and their spacing, the permanent and transition dipole moments (PDM and TDM) have been also investigated. The molecular ion is considered as effective two-electron system. These valence electrons are modeled by a Core Polarization Potential (CPP) and Effective Core Potential (ECP) with l-dependent cutoff functions.

Chemical Physics, May 1, 2012

ABSTRACT For all states dissociating below the ionic limit Li−K+, we perform an adiabatic and dia... more ABSTRACT For all states dissociating below the ionic limit Li−K+, we perform an adiabatic and diabatic study for 1Σ+ electronic states dissociating into K (4s, 4p, 4d, 5s, 5p, 5d, 6s)+Li (2s, 2p, 3s). Furthermore, we present the adiabatic results for the 1–11 3Σ, 1–8 1,3Π and 1–4 1,3Δ states. The present calculations on the KLi molecule are complementary to previous theoretical work on this system, including recently observed electronic states that had not been calculated previously. The calculations rely on an ab initio pseudo-potential, Core Polarization Potential operators for the core–valence correlation and full valence CI approaches, combined to an efficient diabatization procedure. For the low-lying states, our spectroscopic constants and vibrational level spacing are in good agreement with the available experimental data. Diabatic potentials and permanent dipole moments are analyzed, revealing the strong imprint of the ionic state in the 1Σ+ adiabatic states.

Journal of Computational Chemistry, Jun 26, 2013

For all states dissociating below the ionic limit Li− Rb+, we perform a diabatic study for 1Σ+ el... more For all states dissociating below the ionic limit Li− Rb+, we perform a diabatic study for 1Σ+ electronic states dissociating into Rb (5s, 5p, 4d, 6s, 6p, 5d, 7s, 4f) + Li (2s, 2p, 3s). Furthermore, we present the diabatic results for the 1–11 3σ, 1–8 1,3Π, and 1–4 1,3Δ states. The present calculations on the RbLi molecule are complementary to previous theoretical work on this system, including recently observed electronic states that had not been calculated previously. The calculations rely on ab‐initio pseudopotential, core polarization potential operators for the core‐valence correlation and full valence configuration interaction approaches, combined to an efficient diabatization procedure. For the low‐lying states, diabatic potentials and permanent dipole moments are analyzed, revealing the strong imprint of the ionic state in the 1Σ+ adiabatic states. The transition dipole moment is used to evaluate the radiative lifetimes of the vibrational levels trapped in the 2 1Σ+ excited states for the first time. In addition to the bound–bound contribution, the bound–free term has been evaluated using the Franck–Condon approximation and also exactly added to the total radiative lifetime. © 2013 Wiley Periodicals, Inc.

International Journal of Quantum Chemistry, Mar 13, 2014

A wide adiabatic study is performed for NaRb molecule, involving 151Σ+ electronic states includin... more A wide adiabatic study is performed for NaRb molecule, involving 151Σ+ electronic states including the ionic state Na−Rb+, as well as 143Σ+, 1–91,3Π, and 1–51,3Δ states. This investigation is performed using an ab initio approach which involves the effective core potential, the core polarization potential with l‐dependent cut‐off functions. The NaRb system has been treated as a two‐electron system and the full valence configuration interaction is easily achieved. The spectroscopic constants Re, De, Te, ωe, ωexe, Be, and D0 for all these states are derived. We have also computed the vibrational levels as well their spacing for different values of J. In addition, permanent and transition dipole moments are determined and analyzed. The Dunham coefficients have been used to perform experimental spacing to compare directly with our results. The present calculations on NaRb extend previous theoretical works to numerous electronic excited states in the various symmetries. © 2014 Wiley Periodicals, Inc.

Journal of Physical Chemistry A, Nov 14, 2011

The diabatic and adiabatic potential-energy curves and permanent and transition dipole moments of... more The diabatic and adiabatic potential-energy curves and permanent and transition dipole moments of the highly excited states of the CaH(+) molecular ion have been computed as a function of the internuclear distance R for a large and dense grid varying from 2.5 to 240 au. The adiabatic results are determined by an ab initio approach involving a nonempirical pseudopotential for the Ca core, operatorial core-valence correlation, and full valence configuration interaction. The molecule is thus treated as a two-electron system. The diabatic potential energy curves have been calculated using an effective metric combined to the effective Hamiltonian theory. The diabatic potential-energy curves and their permanent dipole moments for the (1)∑(+) symmetry are examined and corroborate the high imprint of the ionic state in the adiabatic representation. Taking the benefit of the diabatization approach, correction of hydrogen electron affinity was taken into account leading to improved results for the adiabatic potentials but also the permanent and transition electric dipole moments.

International Journal of Quantum Chemistry, Nov 13, 2014

ABSTRACT The potentials, spectroscopic properties and electric dipole moments of SrH+ are compute... more ABSTRACT The potentials, spectroscopic properties and electric dipole moments of SrH+ are computed for 63 molecular states dissociating up to Sr2+ + H− using an ab initio approach. The ab initio formalism is based on large basis sets, nonempirical atomic pseudopotential for strontium core, correlation treatment for core valence through the effective core polarization potentials and for valence through full valence configuration interaction. Our theoretical molecular constants match published values very well and a large amount of new results is produced. Unusual potential shapes are found in 1Σ+ states often caused by avoided crossing series between them and imprinted by the ionic state Sr2+H−. The high potential energy curves suggest, it is possible to form H− or at least to neutralize H+ in collisions with strontium. © 2014 Wiley Periodicals, Inc.

Journal of Physics B, Nov 5, 2020

Potential energy curves, spectroscopic parameters, electric dipole moments (PEDM and TEDM) and vi... more Potential energy curves, spectroscopic parameters, electric dipole moments (PEDM and TEDM) and vibrational levels’ spacing for 141Σ+, 133Σ+, 81,3Π, and 31,3Δ electronic states, including the ionic limit K−Cs+, are highly computed and presented in adiabatic representation. These properties are determined by the use of an ab initio method involving non-empirical pseudo-potentials, the core polarization potentials, the l-dependent cut-off functions, and the full valence configuration interaction. An important shape where an ionic state behaving as (−1/R), has been clearly pointed out in the 1Σ+ symmetry. This irregularity has been made due to the ionic charge transfer state (K−Cs+), which induces a series of avoided crossings at intermediate and long internuclear ranges. It is interesting to note that the ionic character linked to the ionic charge transfer K−Cs+ state has been clearly illustrated in the PEDM. The current calculations on the KCs molecule are complementary to the published theoretical works, including recently observed electronic states that had not been calculated previously. For the low-lying electric states, spectroscopic constants, PEDM, as well as TEDM are in good agreement with the available experimental data. The relevant data of the KCs molecule are meaningful and useful in several prospective experiments such as photo-association experiments or the manipulation of ultra-cold molecules.

International Journal of Quantum Chemistry

An extensive diabatic investigation of the NaRb species has been carried out for all excited stat... more An extensive diabatic investigation of the NaRb species has been carried out for all excited states up to the ionic limit Na-Rb 1. An ab initio calculation founded on the pseudopotential, core polarization potential operators and full configuration interaction has been used with an efficient diabatization method involving a combination of variational effective hamiltonian theory and an effective overlap matrix. Diabatic potential energy curves and electric dipole moments (permanent and transition) for all the symmetries R 1 , P, and D have been studied for the first time. Thanks to a unitary rotation matrix, the examination of the diabatic permanent dipole moment (PDM) has shown the ionic feature clearly seen in the diabatic 1 R 1 potential curves and confirming the high imprint of the Na-Rb 1 ionic state in the adiabatic representation. Diabatic transition dipole moments have also been computed. Real crossings have been shown for the diabatic PDM, locating the avoided crossings between the corresponding adiabatic energy curves.

Physica Scripta

A computational study of the electronic structure of the SrKr and Sr+Kr molecular systems is pres... more A computational study of the electronic structure of the SrKr and Sr+Kr molecular systems is presented in this paper. The theoretical approach is based on the pseudo-potential technique for Sr++Kr interaction and core-valence correlation for the one and two electrons-Sr++Kr interaction. The potential energy surfaces (PESs), spectroscopic parameters, electric dipole moments (EDM), and the vibrational levels’ spacing for all electronic states are calculated. The accuracy of the current spectroscopic results is discussed by comparing them to the available experimental and theoretical data. It is interesting to note that several avoided crossings (ACs) have occurred between the high-lying 2Σ+ excited states. Each curve exhibits ionic and neutral branches in the AC region, yielding the appearance of the ionic character and the illustration of charge transfer.

Journal of Molecular Graphics and Modelling

Journal of Quantitative Spectroscopy and Radiative Transfer, 2021

Abstract A non-relativistic description of the electronic structure for the heteronuclear molecul... more Abstract A non-relativistic description of the electronic structure for the heteronuclear molecule KRb was developed through the Full Configuration Interaction (FCI) and pseudo-potential method. Below the ionic limit K−Rb+, the ground and all excited singlet and triplet states of different symmetries Σ+, Π and Δ (in the Hund's case (a): 2s + 1Λ±) were intensively investigated. Several adiabatic results including potential energy curves (PECs), permanent and transition electric dipole moments (PEDM, TEDM) were analyzed in short and long-range of internuclear distances. Tables of these properties as functions of separation are presented. The spectroscopic constants with the vibrational levels were derived using the “Numerov” algorithm. These molecular parameters were compared with those published in the literature, feature a good agreement. In the adiabatic representation, strong couplings between successive 1Σ+ states were reached by series of avoided crossing, yielding to the appearance of the ionic character and the good illustration of charge transfer. This description of the KRb molecule was helpful in the design of the prospect photo-association experiments and the obtaining of the quantum-degenerate gas of the polar molecule.

Journal of Physics B: Atomic, Molecular and Optical Physics, 2020

Potential energy curves, spectroscopic parameters, electric dipole moments (PEDM and TEDM) and vi... more Potential energy curves, spectroscopic parameters, electric dipole moments (PEDM and TEDM) and vibrational levels’ spacing for 141Σ+, 133Σ+, 81,3Π, and 31,3Δ electronic states, including the ionic limit K−Cs+, are highly computed and presented in adiabatic representation. These properties are determined by the use of an ab initio method involving non-empirical pseudo-potentials, the core polarization potentials, the l-dependent cut-off functions, and the full valence configuration interaction. An important shape where an ionic state behaving as (−1/R), has been clearly pointed out in the 1Σ+ symmetry. This irregularity has been made due to the ionic charge transfer state (K−Cs+), which induces a series of avoided crossings at intermediate and long internuclear ranges. It is interesting to note that the ionic character linked to the ionic charge transfer K−Cs+ state has been clearly illustrated in the PEDM. The current calculations on the KCs molecule are complementary to the publish...

Journal of Quantitative Spectroscopy and Radiative Transfer, 2018

This is a PDF file of an unedited manuscript that has been accepted for publication. As a service... more This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Highlights  Electronic energies and dipole moments for the ion CaNa+ are theoretically investigated.  Spectroscopic parameters are derived from potential energy curves.  Vibrational level spacings for selected states are drawn and analyzed.  Numerous avoided crossings are detected in PECs and its reflection in PDM and TDM functions is discussed.

Molecular Physics, 2018

Van der Waals interactions between the valence electrons of the barium atom and the closed-shell ... more Van der Waals interactions between the valence electrons of the barium atom and the closed-shell cores have been studied using ab initio methods with a combination of pseudopotentials and core polarisation potential. We have reported the potential energy curves, the spectroscopic constants, the vibrational levels as well as the electric dipole moments for the ground and several excited states of Ba + Kr and BaKr complexes. Interesting behaviour has been observed in the potential energy curves, particularly for + states. This can show the strong repulsive interactions between Rydberg electrons and the Krypton atom.

Journal of Quantitative Spectroscopy and Radiative Transfer, 2017

This is a PDF file of an unedited manuscript that has been accepted for publication. As a service... more This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Highlights  Investigation the potential energy curves.  Determination the spectroscopic properties.  Investigation the electric dipole moments and vibrationel levels of diatomic molecules.

Molecular Physics, 2016

ABSTRACT The structural and electronic properties of (SrLi)+ molecular ion have been determined b... more ABSTRACT The structural and electronic properties of (SrLi)+ molecular ion have been determined by the use of ab initio approaches. Potential energy curves (PECs) with their spectroscopic constants (Re, De, ωe, Te, Be and ωeχe) have been calculated. Also, the vibrational properties and the electric dipole moments, either permanent (PDM) or transition (TDM) ones, have been investigated and analysed. Large Gaussian basis sets, the full valence configuration interaction (FCI) and the formalism of non-empirical pseudo-potential including the two approaches, effective core potential (ECP) and core polarisation potential (CPP), are analysed. Therefore, (SrLi)+ is considered as a two effective electrons system. Numerous excited states of symmetries 1,3Σ+, 1,3Π and 1,3Δ dissociating below the ionic limit Sr2+Li− have been investigated. This study shows interesting behaviours around the avoided crossing related to charge transfer involving important processes in physics and astrophysics such as dynamics, pre-dissociation and inelastic transitions.

The Journal of Chemical Physics, 2014

The structures and relative stabilities of mixed Ba2+Xen (n = 1–39, 54) clusters have been theore... more The structures and relative stabilities of mixed Ba2+Xen (n = 1–39, 54) clusters have been theoretically studied using basin-hopping global optimization. Analytical potential energy surfaces were constructed from ab initio or experimental data, assuming either purely additive interactions or including many-body polarization effects and the mutual contribution of self-consistent induced dipoles. For both models the stable structures are characterized by the barium cation being coated by a shell of xenon atoms, as expected from simple energetic arguments. Icosahedral packing is dominantly found, the exceptional stability of the icosahedral motif at n = 12 being further manifested at the size n = 32 where the basic icosahedron is surrounded by a dodecahedral cage, and at n = 54 where the transition to multilayer Mackay icosahedra has occurred. Interactions between induced dipoles generally tend to decrease the Xe-Xe binding, leading to different solvation patterns at small sizes but al...

The Journal of Physical Chemistry A, 2013

An adiabatic study of 1-34 1,3 Σ + electronic states of Baruim hydride ion (BaH +) is presented f... more An adiabatic study of 1-34 1,3 Σ + electronic states of Baruim hydride ion (BaH +) is presented for all states dissociating below the ionic limit Ba 2+ H-. The 1-20 Π 3 , 1 and 1-12 ∆ 3 , 1 states have been also investigated. In our approach, the valence electron of Ba 2+ ion is described by an effective core potential (ECP) and core polarization potential (CPP) with l-dependent cutoff functions have been used. The ionic molecule BaH + has been treated as a two-electron system and the full valence configuration interaction (CI) is easily achieved. The spectroscopic constants R e , D e , T e , ω e , ω e x e and B e are derived. In addition, vibrational levels spacing, permanent and transition dipole moments are determined and analyzed. Unusual potentials shapes are found and also accidental quasi degeneracy in the vibrational spacing progression for various excited states. The 1 Σ + states exhibit ionic charge transfer avoided crossings series which could lead to neutralization or even Hformation in collisions of H + with Ba.