Density-functional investigation of the excited state properties and the Jahn—Teller effect in [CrX6]

1995 ◽  
Vol 91 (3) ◽  
pp. 215
Author(s):  
Khalid Bellafrouh ◽  
Claude Daul ◽  
Hans U. Güdel ◽  
François Gilardoni ◽  
Jacques Weber
Keyword(s):  
Excited State ◽  
Density Functional ◽  
Teller Effect ◽  
Jahn Teller ◽  
Jahn Teller Effect ◽  
Functional Investigation

Density-functional investigation of the excited state properties and the Jahn-Teller effect in [CrX6]3? (X=Cl?, Br?)

1995 ◽  
Vol 91 (3-4) ◽  
pp. 215-224 ◽  
Author(s):  
Khalid Bellafrouh ◽  
Claude Daul ◽  
Hans U. G�del ◽  
Fran�ois Gilardoni ◽  
Jacques Weber
Keyword(s):  
Excited State ◽  
Density Functional ◽  
Teller Effect ◽  
Jahn Teller ◽  
Jahn Teller Effect ◽  
Functional Investigation

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.

scholarly journals Strong spin–orbit quenching via the product Jahn–Teller effect in neutral group IV qubits in diamond

2020 ◽  
Vol 5 (1) ◽  
Author(s):  
Christopher J. Ciccarino ◽  
Johannes Flick ◽  
Isaac B. Harris ◽  
Matthew E. Trusheim ◽  
Dirk R. Englund ◽  
...  
Keyword(s):  
Excited State ◽  
Ground State ◽  
Group Iv ◽  
Teller Effect ◽  
Color Centers ◽  
Spin Orbit ◽  
Neutral Group ◽  
Theoretical Understanding ◽  
Jahn Teller ◽  
Jahn Teller Effect

Abstract Artificial atom qubits in diamond have emerged as leading candidates for a range of solid-state quantum systems, from quantum sensors to repeater nodes in memory-enhanced quantum communication. Inversion-symmetric group IV vacancy centers, comprised of Si, Ge, Sn, and Pb dopants, hold particular promise as their neutrally charged electronic configuration results in a ground-state spin triplet, enabling long spin coherence above cryogenic temperatures. However, despite the tremendous interest in these defects, a theoretical understanding of the electronic and spin structure of these centers remains elusive. In this context, we predict the ground-state and excited-state properties of the neutral group IV color centers from first principles. We capture the product Jahn–Teller effect found in the excited state manifold to second order in electron–phonon coupling, and present a nonperturbative treatment of the effect of spin–orbit coupling. Importantly, we find that spin–orbit splitting is strongly quenched due to the dominant Jahn–Teller effect, with the lowest optically-active 3Eu state weakly split into ms-resolved states. The predicted complex vibronic spectra of the neutral group IV color centers are essential for their experimental identification and have key implications for use of these systems in quantum information science.

scholarly journals Jahn-Teller effect in density-functional theory

2019 ◽  
Vol 99 (2) ◽  
Author(s):  
Mark C. Palenik ◽  
Brett I. Dunlap ◽  
Daniel Gunlycke
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Teller Effect ◽  
Functional Theory ◽  
Jahn Teller ◽  
Jahn Teller Effect
Sign in / Sign up

Export Citation Format

Share Document