Symmetry breaking in the planar configurations of disilicon tetrahalides: Pseudo-Jahn–Teller effect parameters, hardness and electronegativity

2015 ◽  
Vol 17 (43) ◽  
pp. 29251-29261 ◽  
Author(s):  
Ghazaleh Kouchakzadeh ◽  
Davood Nori-Shargh
Keyword(s):  
Symmetry Breaking ◽  
Ab Initio ◽  
Teller Effect ◽  
Dft Methods ◽  
Jahn Teller ◽  
Jahn Teller Effect

The correlations between the Pseudo-Jahn–Teller Effect (PJTE) parameters (i.e. F, Δ and K0), structural and configurational properties, global hardness and global electronegativities in disilicon tetrahalides were investigated by means of ab initio and hybrid-DFT methods.

Ab initio investigation of the multimode dynamical Jahn-Teller effect in the X̃ 2E1g state of the benzene cation

1991 ◽  
Vol 177 (3) ◽  
pp. 345-351 ◽  
Author(s):  
J. Eiding ◽  
R. Schneider ◽  
W. Domcke ◽  
H. Köppel ◽  
W. von Niessen
Keyword(s):  
Ab Initio ◽  
Teller Effect ◽  
Jahn Teller ◽  
Jahn Teller Effect

Symmetry breaking in the axial symmetrical configurations of enolic propanedial, propanedithial, and propanediselenal: pseudo Jahn–Teller effect versus the resonance-assisted hydrogen bond theory

2015 ◽  
Vol 93 (6) ◽  
pp. 673-684 ◽  
Author(s):  
Elahe Jalali ◽  
Davood Nori-Shargh
Keyword(s):  
Density Functional Theory ◽  
Hydrogen Bond ◽  
Symmetry Breaking ◽  
Density Functional ◽  
Teller Effect ◽  
Electron Delocalization ◽  
Functional Theory ◽  
Jahn Teller ◽  
Jahn Teller Effect ◽  
Resonance Assisted Hydrogen Bond

The origin of the symmetry breaking in the axial symmetrical configurations of enolic propanedial (1), propanedithial (2), and propanediselenal (3) have been investigated by means of time-dependence density functional theory and natural bond orbital interpretations. The results obtained at the quantum chemistry composite (G2MP2, CBS-QB3), ab initio molecular orbital (MP2/6-311++G**), and hybrid density functional theory (B3LYP/6-311++G**) levels of theory showed that the hydrogen-centered synchronous axial symmetrical (C2v) configurations of compounds 1–3 possessing the maximum π-electron delocalization within the M1=C2–C3=C4–M5–H6 keto-enol groups are less stable than their corresponding plane symmetrical (Cs) forms. Importantly, the symmetry breaking in the C2v configurations of the enol forms of compounds 1–3 to their corresponding plane symmetrical Cs configurations is due to the pseudo Jahn–Teller effect (PJTE) by mixing the ground A1 and excited B2 electronic states resulting in a PJT (A1 + B2) ⊗ b2 problem. We may expect that by the decrease of the energy gaps between reference states in the C2v forms that are involved in the PJTE decrease from compound 1 to compound 3, the PJT stabilization energy (PJTSE) may increase but the results obtained showed that the corresponding PJTSEs decrease. This fact can be justified by the increase of the electron delocalizations from the nonbonding orbitals of the C=M moieties to the antibonding orbitals of the H–M bonds, which leads to an increase of the π-electron delocalization within the M1=C2–C3=C4–M5–H6 keto-enol groups. In confrontation between the impacts of the resonance-assisted hydrogen bond and PJTE in the structural and configurational properties of compounds 1–3, PJTE has an overwhelming contribution and causes the symmetry breaking of the C2v configurations to their corresponding Cs forms. The correlations between the structural parameters, synchronicity indices, natural charges, PJTSEs, electron delocalizations, and the hardness of compounds 1–3 have been investigated.

Ab initio-CI study of SCH 3 radical: analysis of the Jahn–Teller effect in the ground state

2000 ◽  
Vol 497 (1-3) ◽  
pp. 197-203 ◽  
Author(s):  
R. Drissi El Bouzaidi ◽  
A. El Hammadi ◽  
A. Boutalib ◽  
M. El Mouhtadi
Keyword(s):  
Ab Initio ◽  
Ground State ◽  
Teller Effect ◽  
Jahn Teller ◽  
Jahn Teller Effect
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