Analysis of the concept of minimum energy path on the potential energy surface of chemically reacting systems

1984 ◽  
Vol 66 (3-4) ◽  
pp. 245-260 ◽  
Author(s):  
Wolfgang Quapp ◽  
Dietmar Heidrich
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Energy Surface ◽  
Minimum Energy ◽  
Minimum Energy Path ◽  
Chemically Reacting Systems ◽  
Chemically Reacting ◽  
Reacting Systems

THE PARTIAL POTENTIAL ENERGY SURFACE AND SCATTERING RESONANCE STATE OF THE STATE-TO-STATE REACTION Br + HBr(v) → BrH(v′) + Br

2006 ◽  
Vol 05 (spec01) ◽  
pp. 307-316 ◽  
Author(s):  
HUAYANG WANG ◽  
XIAOMIN SUN ◽  
DACHENG FENG ◽  
ZHENGTING CAI
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Energy Surface ◽  
Minimum Energy ◽  
Resonance State ◽  
Minimum Energy Path ◽  
Resonance States ◽  
One Dimensional ◽  
Well Model ◽  
The One

In this paper, the partial potential energy surface (PPESs) of the Br + HBr and Br - + HBr systems including the minimum energy path and the vibrational potential curves were constructed at MP2/6-311++G** level, based on the conception and constructing approach of the PPESs previously proposed. These results obtained from the PPESs were compared with those from the high resolved threshold photodetachment spectrum of the BrHBr - anion measured by Neumark et al., J Phys Chem94, 1377–1388, 1990. On the basis of the PPESs, the scattering resonance states of the Br + HBr (v) → BrH (v′) + Br state-to-state reaction were studied and the satisfactory results were obtained. Subsequently, we calculated the width and lifetime of the resonance states in this reaction by the one-dimensional square potential well model, and obtained some results consistent to the experiments.

scholarly journals Density functional theory study of the Jahn-Teller effect in cobaltocene

2009 ◽  
Vol 81 (8) ◽  
pp. 1397-1411 ◽  
Author(s):  
Matija Zlatar ◽  
Carl-Wilhelm Schläpfer ◽  
Emmanuel Penka Fowe ◽  
Claude A. Daul
Keyword(s):  
Density Functional Theory ◽  
Potential Energy ◽  
Potential Energy Surface ◽  
Density Functional ◽  
Energy Surface ◽  
Minimum Energy ◽  
Normal Modes ◽  
Coupling Coefficients ◽  
Functional Theory ◽  
Jahn Teller

A detailed discussion of the potential energy surface of bis(cyclopentadienyl)cobalt(II), cobaltocene, is given. Vibronic coupling coefficients are calculated using density functional theory (DFT). Results are in good agreement with experimental findings. On the basis of our calculation there is no second-order Jahn–Teller (JT) effect as predicted by group theory. The JT distortion can be expressed as a linear combination of all totally symmetric normal modes of the low-symmetry, minimum-energy conformation. The out-of-plane ring deformation is the most important mode. The JT distortion is analyzed by seeking the path of minimal energy of the adiabatic potential energy surface.

Partial Potential Energy Surfaces and Their Application to Reaction Resonances

2017 ◽  
Vol 42 (3) ◽  
pp. 300-305
Author(s):  
Ang-Yang Yu
Keyword(s):  
Potential Energy ◽  
Potential Energy Surfaces ◽  
Energy Surface ◽  
Minimum Energy ◽  
Reactive Systems ◽  
Resonance State ◽  
Minimum Energy Path ◽  
Feshbach Resonances ◽  
Energy Surfaces ◽  
Elementary Chemical

Feshbach resonances are not restricted to small reactive systems such as F + H2 and I + HI but can be found in many reactive systems. In this paper, the concept of the partial potential energy surface (PPES) is introduced. It is shown that the dynamic “Lake Eyring” explains very well the existence of reactive resonances in elementary chemical reactions. In particular, the PPESs of the Cl + CH3CH2Br and Cl + CH3CH2CH2Br systems, including the minimum energy path and the vibrational potential energy curves, were constructed using quantum chemistry methods. Based on the constructed PPESs, the scattering resonance states of these reactions could be examined and the resonance state lifetimes were estimated.

scholarly journals Improved Potential Energy Surface of Ozone Constructed Using the Fitting by Permutationally Invariant Polynomial Function

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Mehdi Ayouz ◽  
Dmitri Babikov
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Energy Surface ◽  
Polynomial Function ◽  
Minimum Energy ◽  
Basis Set ◽  
Invariant Polynomial ◽  
Complete Basis Set ◽  
Data Points ◽  
Small Set

New global potential energy surface for the ground electronic state of ozone is constructed at the complete basis set level of the multireference configuration interaction theory. A method of fitting the data points by analytical permutationally invariant polynomial function is adopted. A small set of 500 points is preoptimized using the old surface of ozone. In this procedure the positions of points in the configuration space are chosen such that the RMS deviation of the fit is minimized. New ab initio calculations are carried out at these points and are used to build new surface. Additional points are added to the vicinity of the minimum energy path in order to improve accuracy of the fit, particularly in the region where the surface of ozone exhibits a shallow van der Waals well. New surface can be used to study formation of ozone at thermal energies and its spectroscopy near the dissociation threshold.

scholarly journals Structures and stabilities of C2H2F3+ cations: an abinitio molecular orbital study

1987 ◽  
Vol 65 (3) ◽  
pp. 473-481 ◽  
Author(s):  
Micheline Charpentier ◽  
Jacques Fossey ◽  
Thomas T. Tidwell ◽  
Saul Wolfe
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Energy Surface ◽  
Atomic Orbital ◽  
Minimum Energy ◽  
Saddle Points ◽  
Lone Pair ◽  
Basis Set ◽  
Stationary Points ◽  
Energy Structure

Eleven stationary points on the singlet C2H2F3+ potential energy surface have been calculated using the 3-21G basis set, and characterized as minima (four structures) or first-order saddle points (seven structures) by vibrational analysis. To check the reliability of this basis set, three of the structures have also been optimized at the 6-31G* level; although the geometries change somewhat, the relative energies and nature (maxima, minima) of the structures remain the same. For CF3CH2+ the minimum energy structure has one C—F bond coplanar with the vacant p-atomic orbital at the cationic centre. The structure is 16.4 kcal/mol less stable than the lowest energy conformation of FCH2CF2+, and the barrier for the 1,2 fluorine migration which connects the two structures is low. The cation F2CHCHF+ has a conformation that is a minimum on the potential energy surface that is 16.9 kcal/mol higher in energy than FCH2CF2+; the two structures are separated by a barrier for 1,2 hydrogen migration of 23.5 kcal/mol. The electronic effects in the various structures have been studied using a quantitative PMO analysis of the interactions between the two carbon fragments of the ions. For CF3CH2+ the net effect of the fluorine is highly destabilizing; the principal stabilizing interactions between CF3+ and CH2 consist of π donation from CF3+ to CH2 and homoconjugation of a fluorine lone pair with the cationic centre. No net stabilization attributable to fluorine bridging could be found.

scholarly journals A DFT and multi-configurational perturbation theory study on O2 binding to a model heme compound via the spin-change barrier

2016 ◽  
Vol 18 (27) ◽  
pp. 18137-18144 ◽  
Author(s):  
Y. Kitagawa ◽  
Y. Chen ◽  
N. Nakatani ◽  
A. Nakayama ◽  
J. Hasegawa
Keyword(s):  
Perturbation Theory ◽  
Potential Energy ◽  
Potential Energy Surface ◽  
Energy Surface ◽  
Vibration Mode ◽  
Minimum Energy ◽  
Intersystem Crossing ◽  
Crossing Point ◽  
O2 Binding

Potential energy surface of the O2 binding to a model heme compound via minimum energy intersystem crossing point (MEISCP) was investigated with DFT and MS-CASPT2. The porphyrin's symmetric shrinking vibration mode contributes to reach the MESICP from the T1 minimum.

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