scholarly journals Applying ab initio Calculations to Theoretically Investigate the Electronic Structure of the Calcium Sulfide Molecule CaS

2018 ◽  
Vol 13 (1) ◽  
pp. 1
Author(s):  
Hanan Hijazi ◽  
Mahmoud Korek
Keyword(s):  
Ab Initio ◽  
Internuclear Distance ◽  
Ground State ◽  
Dipole Moments ◽  
Electronic States ◽  
Rotational Constant ◽  
Electronic Energy ◽  
Spectroscopic Constants ◽  
Calcium Sulfide ◽  
Complete Active Space

Using the graphical user interface GABEDIT and the computational chemistry software MOLPRO, the ab initio calculation method has been applied to explore 25 low-lying singlet and triplet electronic states, including the X1Σ+ ground state, of the calcium sulfide molecule CaS in the 2s+1Λ± representation. The multi-reference configuration interaction with Davidson correction (MRCI+Q) and the complete active space self-consistent field (CASSCF) calculations were performed to obtain the potential energy curves in terms of the internuclear distance R. The permanent dipole moments μe of these low-lying electronic states of CaS have been investigated, in addition to the corresponding spectroscopic constants (including the electronic energy with respect to the ground state Te, the equilibrium internuclear distance Re, the harmonic vibrational frequency ωe, the rotational constant Be, and the equilibrium dissociation energy De). In the present work, 19 new singlet and triplet CaS electronic states were investigated for the first time. In addition, it is noticeable that the current results and those already available in literature are in good agreement.

scholarly journals Theoretical Investigation of the Electronic Structure of the Strontium Mono-Sulfide Molecule SrS Using the ab initio Calculation Method

2018 ◽  
Vol 12 (8) ◽  
pp. 81
Author(s):  
Hanan Hijazi ◽  
Mahmoud Korek
Keyword(s):  
Ab Initio ◽  
Internuclear Distance ◽  
Ground State ◽  
Dipole Moments ◽  
Electronic States ◽  
Rotational Constant ◽  
Electronic Energy ◽  
Spectroscopic Constants ◽  
Complete Active Space ◽  
Self Consistent Field

AbstractThe ground state and 23 other low-lying singlet and triplet electronic states of the strontium mono-sulfide molecule SrS, in the 2s+1Λ± representation, have been examined by ab initio calculations using the computational chemistry software MOLPRO and the graphical user interface GABEDIT. The potential energy curves, in terms of the internuclear distance R, resulted from the complete active space self-consistent field (CASSCF) and multi-reference doubly and singly configuration interaction (MRDSCI) with Davidson correction (+Q) calculations. The permanent dipole moments (μ) and the spectroscopic constants (Te: the electronic energy with respect to the ground state, ωe: the harmonic frequency, Re: the equilibrium internuclear distance, Be: the rotational constant, De: the equilibrium dissociation energy) have been investigated. The results of this work are in good agreement with the results available in literature. Moreover, for the first time, it was possible to study 20 new singlet and triplet electronic states of SrS molecule.

Theoretical electronic investigation of the low-lying electronic states of the LuF molecule

2009 ◽  
Vol 87 (11) ◽  
pp. 1163-1169 ◽  
Author(s):  
Y. Hamade ◽  
F. Taher ◽  
M. Choueib ◽  
Y. Monteil
Keyword(s):  
Ground State ◽  
Electronic States ◽  
Electronic Energy ◽  
Wave Number ◽  
Spectroscopic Constants ◽  
Complete Active Space ◽  
Consistent Field ◽  
Self Consistent ◽  
Self Consistent Field ◽  
Calculated Potential Energy

The theoretical electronic structure of the LuF molecule is investigated, using the Complete Active-Space Self-Consistent Field CASSCF and the MultiReference Configuration Interaction MRCI methods. These methods are performed for 26 electronic states in the representation 2s+1Λ(+/−), neglecting spin–orbit effects. Spectroscopic constants including the harmonic vibrational wave number ωe (cm–1), the relative electronic energy Te (cm–1) referred to the ground state and the equilibrium internuclear distance Re (Å) are predicted for all the singlet and triplet electronic states situated below 50 000 cm–1. Calculated potential energy curves are also reported.

scholarly journals Electronic Structure and Dipole Moment Calculations of the Electronic States of the Molecule ZnS

2018 ◽  
Vol 12 (3) ◽  
pp. 132
Author(s):  
Abeer Youssef ◽  
Ghassan Younes ◽  
Mahmoud Korek
Keyword(s):  
Dipole Moment ◽  
Dipole Moments ◽  
Electronic States ◽  
Rotational Constant ◽  
Electronic Energy ◽  
Complete Active Space ◽  
Accurate Picture ◽  
Self Consistent Field ◽  
Highly Correlated ◽  
First Time

In this study, the low lying electronic states and spectroscopy of diatomic molecule ZnS in addition to its dipole moments have been investigated by performing highly correlated ab initio calculations, the Complete Active Space Self Consistent Field (CASSCF) method with Multi Reference Configuration Interaction (MRCI+Q) for an accurate picture for these states. The proposed study includes information about the potential energy curves of the lowest 12 singlet and 9 triplet electronic states of the molecule ZnS, in the representation 2s+1Λ(+/-). Nine of these states have been studied here for the first time. The harmonic frequency we, the internuclear distance re, the electronic energy with respect to the ground state Te, the rotational constant Be, and the permanent dipole moment μ have been calculated, compared and compiled with the available existing data to illustrate the electronic characteristics. The comparison of these values reveals a very good agreement.

scholarly journals Electronic structure with dipole moment and ionicity calculations of the low-lying electronic states of the ZnF molecule

2017 ◽  
Vol 95 (1) ◽  
pp. 22-27 ◽  
Author(s):  
Soumaya Elmoussaoui ◽  
Nayla El-Kork ◽  
Mahmoud Korek
Keyword(s):  
Dipole Moment ◽  
Ground State ◽  
Bound States ◽  
Radiative Lifetime ◽  
Electronic States ◽  
Rotational Constant ◽  
Transition Dipole Moment ◽  
Transition Dipole ◽  
Complete Active Space ◽  
Self Consistent Field

Adiabatic potential energy curves of the 28 low-lying doublet and quartet electronic states in the representation 2s+1Λ(±) of the zinc monofluoride molecule are investigated using the complete active space self-consistent field (CASSCF) with multi-reference configuration interaction (MRCI) method including single and double excitations with the Davidson correction (+Q). The internuclear distance Re, the harmonic frequency ωe, the static and transition dipole moment μ, the rotational constant Be, and the electronic transition energy with respect to the ground state Te are calculated for the bound states. The transition dipole moment between some doublet states is used to determine the Einstein spontaneous A21 and induced emission [Formula: see text] coefficients, as well as the spontaneous radiative lifetime τspon, emission wavelength λ21, and oscillator strength f21. The ground state ionicity qionicity and equilibrium dissociation energy DE,e are also computed. The comparison between the values of the present work and those available in the literature for several electronic states shows very good agreement. Twenty-three new electronic states have been studied in the present work for the first time.

Ab initio calculation of the low-lying electronic states of the ZrN molecule

2012 ◽  
Vol 90 (7) ◽  
pp. 631-639 ◽  
Author(s):  
A. Farhat ◽  
M. Korek ◽  
M.A.L. Marques ◽  
S.N. Abdul-Al
Keyword(s):  
Ab Initio ◽  
Ab Initio Calculation ◽  
Electronic States ◽  
Electronic Energy ◽  
Zirconium Nitride ◽  
Harmonic Frequency ◽  
Complete Active Space ◽  
Self Consistent Field ◽  
First Time ◽  
Good Agreement

An ab initio calculation of the low-lying electronic states of zirconium nitride (ZrN) were performed by using a complete active space self-consistent field with multireference single and double excitation configuration interaction (MRSDCI). The potential energy curves of 21 low-lying electronic states of the ZrN molecule with different spin and spatial symmetries, in the representation 2s+1Λ(+/−) and below 30 000 cm–1, were identified. The harmonic frequency (ωe), the equilibrium internuclear distance (Re), the rotational constants (Be), the electronic energy with respect to the ground state (Te), and the permanent dipole moment (µ) were calculated for the considered electronic states. The comparison of these values with those available in the literature shows a very good agreement with either theoretical or experimental data. Fifteen new electronic states were studied here for the first time.

Theoretical calculation of the low-lying electronic states of the LaH molecule

2014 ◽  
Vol 92 (9) ◽  
pp. 855-861 ◽  
Author(s):  
Salman Mahmoud ◽  
Mahmoud Korek
Keyword(s):  
Potential Energy ◽  
Internuclear Distance ◽  
Ground State ◽  
Electronic States ◽  
Electronic Energy ◽  
Centrifugal Distortion ◽  
Harmonic Frequency ◽  
Rotational Constants ◽  
Centrifugal Distortion Constants ◽  
First Time

The potential energy curves of the low-lying electronic states of the LaH molecule are reported via the CASSCF method with multireference calculations (single and double excitations with Davidson corrections). Twenty-four low-lying electronic states of the LaH molecule in the representation 2s+1Λ(+/−) below 20 000 cm−1 were investigated along with five lower electronic states in the Ω representation. The harmonic frequency ωe, the equilibrium internuclear distance Re, the rotational constants Be, and the electronic energy with respect to the ground state Te were calculated for these states. Twelve new electronic states are investigated in the present work for the first time that have not yet been observed experimentally. Using the canonical functions approach, the eigenvalues Ev, the rotational constants Bv, the centrifugal distortion constants Dv, and the abscissas of the turning points Rmin and Rmax were calculated for the investigated electronic states up to vibrational level v = 43.

Theoretical calculation of the low-lying quartet states of the CrF molecule

2011 ◽  
Vol 89 (10) ◽  
pp. 1304-1311 ◽  
Author(s):  
A. Hamdan ◽  
M. Korek
Keyword(s):  
Dipole Moment ◽  
Potential Energy ◽  
Ground State ◽  
Electronic States ◽  
Rotational Constant ◽  
Electronic Energy ◽  
Harmonic Frequency ◽  
First Time ◽  
Theoretical Results ◽  
Good Agreement

The potential energy curves have been investigated for the 11 lowest quartet electronic states in the 2s+1Λ± representation below 28 000 cm–1 of the molecule CrF via CASSCF and MRCI (single and double excitations with Davidson correction) calculations. Eight electronic states have been studied theoretically for the first time. The harmonic frequency ωe, the internuclear distance re, the rotational constant Be, the electronic energy with respect to the ground state Te, and the permanent dipole moment μ have been calculated. By using the canonical functions approach, the eigenvalues Ev, the rotational constant Bv, and the abscissas of the turning points rmin and rmax have been calculated for electronic states up to the vibrational level v = 38. The comparison of these values to the theoretical results available in the literature shows a very good agreement.

Ab initio calculations of the XI molecules (X = Li, Na, K, Rb) with the ionicity and laser cooling analysis

2020 ◽  
Vol 98 (1) ◽  
pp. 45-56 ◽  
Author(s):  
Israa Zeid ◽  
Rania Al Abdallah ◽  
Nayla El-Kork ◽  
Mahmoud Korek
Keyword(s):  
Dipole Moment ◽  
Ab Initio ◽  
Laser Cooling ◽  
Ground State ◽  
Bound States ◽  
Electronic States ◽  
Spectroscopic Constants ◽  
Ionic Character ◽  
Canonical Function ◽  
Dissociation Energies

For the alkali iodide molecules LiI, NaI, KI, and RbI, ab initio CASSCF/(MRCI+Q) calculations have been employed to investigate the adiabatic potential energy curves and the static dipole moment curves of the low-lying singlet and triplet electronic states in the representation 2S+1Λ(+/−). The spectroscopic constants Te, Re, ωe, Be, αe, the dipole moment μe, and the dissociation energies De have been computed for the bound states. Additionally, the percentage ionic character fionic around the equilibrium position of the ground state and the (2)1Σ+ state has been estimated. Using the canonical function approach, these calculations have been followed by a rovibrational calculation from which the rovibrational constants Ev, Bv, Dv, and the abscissas of the turning points Rmin and Rmax for the investigated bound states are calculated.

scholarly journals Electronic Structure and Dipole Moment Calculations of the Electronic States of the Molecule BeCl

2017 ◽  
Vol 11 (6) ◽  
pp. 90
Author(s):  
Boushra El Rafei ◽  
Sahar Kontar ◽  
Ghassan Younes ◽  
Mahmoud Korek
Keyword(s):  
Electronic Structure ◽  
Dipole Moment ◽  
Internuclear Distance ◽  
Electronic States ◽  
Electronic Energy ◽  
Limited Data ◽  
Complete Active Space ◽  
Self Consistent Field ◽  
First Time ◽  
Franck Condon

The electronic structure of the molecule BeCl have been investigated by using the Complete Active Space Self Consistent Field (CASSCF) with Multireference Configuration Interaction MRCI+Q (singly and doubly excitation with Davidson corrections). The potential energy curves, in terms of the internuclear distance R, have been calculated for 13 doublet and 14 quartet electronic states in the representation 2s+1Λ(+/-) of the molecule BeCl. The internuclear distance at equilibrium Re, the electronic energy with respect to the ground state Te, the harmonic frequency we, the rotational constants Be and the permanent dipole moment have been calculated for the bound electronic states. The Franck-Condon factor is calculated for the electronic transition between the two electronic states X2S+-(1)2P. Since there is limited data are published in literature, twenty-two new electronic states have been investigated here for the first time for the molecule BeCl. The comparison between our calculated values and those available in the literature shows a very good good agreement.

The Low-Lying Excited Electronic States of an Alkali-Earth Compounds

2011 ◽  
Vol 324 ◽  
pp. 282-285 ◽  
Author(s):  
Mahmoud Korek ◽  
Hadeel Razzouk ◽  
Rasha Abou Arkoub ◽  
Sara El Atwani
Keyword(s):  
Potential Energy ◽  
Ground State ◽  
Ab Initio Calculation ◽  
Alkaline Earth ◽  
Electronic States ◽  
Rotational Constant ◽  
Electronic Energy ◽  
Excited Electronic States ◽  
Harmonic Frequency ◽  
Good Agreement

Since there is lack in the excited electronic states of alkaline earth compound, candidate for ultracold investigation, and by using an ab initio calculation the potential energy curves have been obtained for the lowest electronic states in the2s+1Λ(±)representation below 53000 cm-1along with the harmonic frequency we, the internuclear distance re, the rotational constant Be, and the electronic energy with respect to the ground state Te. The comparison of these values to the theoretical and experimental results available in the literature shows a good agreement

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