TY  - JOUR
AU  - Garcia-Fernandez, Pablo
AU  - Aramburu, Antonio Jose
AU  - Moreno, Miguel
AU  - Zlatar, Matija
AU  - Gruden-Pavlović, Maja
PY  - 2014
UR  - https://cer.ihtm.bg.ac.rs/handle/123456789/1519
AB  - Vibronic coupling theory shows that the cause for spontaneous instability in systems presenting a nondegenerate ground state is the so-called pseudo-Jahn-Teller effect, and thus its study can be extremely helpful to understand the structure of many molecules. While this theory, based on the mixing of the ground and excited states with a distortion, has been long studied, there are two obscure points that we try to clarify in the present work. First, the operators involved in both the vibronic and nonvibronic parts of the force constant take only into account electron nuclear and nuclear nuclear interactions, apparently leaving electron electron repulsions and the electron's kinetic energy out of the chemical picture. Second, a fully quantitative computational appraisal of this effect has been up to now problematic. Here, we present a reformulation of the pseudo-Jahn-Teller theory that explicitly shows the contributions of all operators in the molecular Hamiltonian and allows connecting the results obtained with this model to other chemical theories relating electron distribution and geometry. Moreover, we develop a practical approach based on Hartree-Fock and density functional theory that allows quantification of the pseudo-Jahn-Teller effect. We demonstrate the usefulness of our method studying the pyramidal distortion in ammonia and its absence in borane, revealing the strong importance of the kinetic energy of the electrons in the lowest a(2)'' orbital to trigger this instability. The present tool opens a window for exploring in detail the actual microscopic origin of structural instabilities in molecules and solids.
PB  - American Chemical Society (ACS)
T2  - Journal of Chemical Theory and Computation
T1  - A Practical Computational Approach to Study Molecular Instability Using the Pseudo-Jahn-Teller Effect
VL  - 10
IS  - 4
SP  - 1824
EP  - 1833
DO  - 10.1021/ct4011097
ER  - 

@article{
author = "Garcia-Fernandez, Pablo and Aramburu, Antonio Jose and Moreno, Miguel and Zlatar, Matija and Gruden-Pavlović, Maja",
year = "2014",
abstract = "Vibronic coupling theory shows that the cause for spontaneous instability in systems presenting a nondegenerate ground state is the so-called pseudo-Jahn-Teller effect, and thus its study can be extremely helpful to understand the structure of many molecules. While this theory, based on the mixing of the ground and excited states with a distortion, has been long studied, there are two obscure points that we try to clarify in the present work. First, the operators involved in both the vibronic and nonvibronic parts of the force constant take only into account electron nuclear and nuclear nuclear interactions, apparently leaving electron electron repulsions and the electron's kinetic energy out of the chemical picture. Second, a fully quantitative computational appraisal of this effect has been up to now problematic. Here, we present a reformulation of the pseudo-Jahn-Teller theory that explicitly shows the contributions of all operators in the molecular Hamiltonian and allows connecting the results obtained with this model to other chemical theories relating electron distribution and geometry. Moreover, we develop a practical approach based on Hartree-Fock and density functional theory that allows quantification of the pseudo-Jahn-Teller effect. We demonstrate the usefulness of our method studying the pyramidal distortion in ammonia and its absence in borane, revealing the strong importance of the kinetic energy of the electrons in the lowest a(2)'' orbital to trigger this instability. The present tool opens a window for exploring in detail the actual microscopic origin of structural instabilities in molecules and solids.",
publisher = "American Chemical Society (ACS)",
journal = "Journal of Chemical Theory and Computation",
title = "A Practical Computational Approach to Study Molecular Instability Using the Pseudo-Jahn-Teller Effect",
volume = "10",
number = "4",
pages = "1824-1833",
doi = "10.1021/ct4011097"
}

Garcia-Fernandez, P., Aramburu, A. J., Moreno, M., Zlatar, M.,& Gruden-Pavlović, M.. (2014). A Practical Computational Approach to Study Molecular Instability Using the Pseudo-Jahn-Teller Effect. in Journal of Chemical Theory and Computation
American Chemical Society (ACS)., 10(4), 1824-1833.
https://doi.org/10.1021/ct4011097

Garcia-Fernandez P, Aramburu AJ, Moreno M, Zlatar M, Gruden-Pavlović M. A Practical Computational Approach to Study Molecular Instability Using the Pseudo-Jahn-Teller Effect. in Journal of Chemical Theory and Computation. 2014;10(4):1824-1833.
doi:10.1021/ct4011097 .

Garcia-Fernandez, Pablo, Aramburu, Antonio Jose, Moreno, Miguel, Zlatar, Matija, Gruden-Pavlović, Maja, "A Practical Computational Approach to Study Molecular Instability Using the Pseudo-Jahn-Teller Effect" in Journal of Chemical Theory and Computation, 10, no. 4 (2014):1824-1833,
https://doi.org/10.1021/ct4011097 . .