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

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.

2018 ◽  
Vol 13 (1) ◽  
pp. 1
Author(s):  
Hanan Hijazi ◽  
Mahmoud Korek

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.


2017 ◽  
Vol 95 (1) ◽  
pp. 22-27 ◽  
Author(s):  
Soumaya Elmoussaoui ◽  
Nayla El-Kork ◽  
Mahmoud Korek

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.


2018 ◽  
Vol 12 (8) ◽  
pp. 81
Author(s):  
Hanan Hijazi ◽  
Mahmoud Korek

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.


2002 ◽  
Vol 09 (01) ◽  
pp. 153-158 ◽  
Author(s):  
WEIDONG ZHOU ◽  
D. P. SECCOMBE ◽  
R. Y. L. CHIM ◽  
R. P. TUCKETT

Threshold photoelectron–photoion coincidence (TPEPICO) spectroscopy has been used to investigate the decay dynamics of the valence electronic states of the parent cation of several hydrofluorocarbons (HFC), based on fluorine-substituted ethane, in the energy range 11–25 eV. We present data for CF 3– CHF 2, CF 3– CH 2 F , CF 3– CH 3 and CHF 2– CH 3. The threshold photoelectron spectra (TPES) of these molecules show a common feature of a broad, relatively weak ground state, associated with electron removal from the highest-occupied molecular orbital (HOMO) having mainly C–C σ-bonding character. Adiabatic and vertical ionisation energies for the HOMO of the four HFCs are presented, together with corresponding values from ab initio calculations. For those lower-energy molecular orbitals associated with non-bonding fluorine 2pπ lone pair electrons, these electronic states of the HFC cation decay impulsively by C–F bond fission with considerable release of translational kinetic energy. Appearance energies are presented for formation of the daughter cation formed by such a process (e.g. CF 3– CHF +), together with ab initio energies of the corresponding dissociation channel (e.g. CF 3– CHF + + F ). Values for the translational kinetic energy released are compared with the predictions of a pure-impulsive model.


2008 ◽  
Vol 128 (4) ◽  
pp. 044304 ◽  
Author(s):  
Lorenzo Lodi ◽  
Roman N. Tolchenov ◽  
Jonathan Tennyson ◽  
A. E. Lynas-Gray ◽  
Sergei V. Shirin ◽  
...  

2019 ◽  
Vol 882 (2) ◽  
pp. 86 ◽  
Author(s):  
Zhongxing Xu ◽  
Nan Luo ◽  
S. R. Federman ◽  
William M. Jackson ◽  
Cheuk-Yiu Ng ◽  
...  

2018 ◽  
Vol 12 (6) ◽  
pp. 970-976
Author(s):  
S. O. Adamson ◽  
D. D. Kharlampidi ◽  
G. V. Golubkov ◽  
M. I. Manzhelii ◽  
S. S. Nabiev ◽  
...  

2006 ◽  
Vol 239 (1) ◽  
pp. 71-87 ◽  
Author(s):  
Sergei N. Yurchenko ◽  
Miguel Carvajal ◽  
Walter Thiel ◽  
Per Jensen

2009 ◽  
Vol 87 (11) ◽  
pp. 1163-1169 ◽  
Author(s):  
Y. Hamade ◽  
F. Taher ◽  
M. Choueib ◽  
Y. Monteil

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.


1957 ◽  
Vol 35 (10) ◽  
pp. 1204-1214 ◽  
Author(s):  
R. Velasco

The absorption spectra of LiH and LiD have been observed in the near ultraviolet with high dispersion and absorbing path lengths up to 16 meters. A new band system has been found in each molecule involving the ground state and a 1Π excited state. Rotational and vibrational analyses of this system have been carried out and rotational and vibrational constants for the upper state have been determined. The observed breaking off of the rotational structure of the bands of this B1Π—X1Σ+ system has been interpreted as due to predissociation by rotation. With this assumption very accurate dissociation limits of the B1Π state have been obtained. From these dissociation limits the dissociation energies of the three known electronic states of LiH and LiD have been calculated. In particular the dissociation energies (D0) of the ground states of LiH and LiD have been found to be 2.4288 ± 0.0002 ev. and 2.4509 ± 0.0010 ev., respectively.


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