scholarly journals Estimating Relative Disulfide Energies: An Accurate Ab Initio Potential Energy Surface

2010 ◽  
Vol 63 (3) ◽  
pp. 379 ◽  
Author(s):  
Naomi L. Haworth ◽  
Jason Y. Liu ◽  
Samuel W. Fan ◽  
Jill E. Gready ◽  
Merridee A. Wouters
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Redox Potential ◽  
Good Predictor ◽  
Web Application ◽  
Energy Surface ◽  
Basis Set ◽  
Dihedral Angles ◽  
High Level ◽  
Highly Strained

Disulfide torsional energy, a good predictor of disulfide redox potential in proteins, may be estimated by interpolation on a potential energy surface (PES) describing the twisting of diethyl disulfide through its three central dihedral angles. Here we update PES calculations at the M05-2X level of theory with the 6-31G(d) basis set. Although the surface shows no qualitative differences from an earlier MP2(full) PES, energy differences greater than 1 kJ mol–1 were seen for conformations with χ2 between –60° and 30°, or with χ3 below 60° or above 130°. This is particularly significant for highly strained disulfides that are likely to be spontaneously reduced by mechanical means. In benchmarking against the high-level G3X method, M05-2X showed significantly reduced root mean squared deviation compared with MP2(full) (1.0 versus 2.0 kJ mol–1 respectively). Results are incorporated into a web application that calculates relative torsional energies from disulfide dihedral angles (http://www.sbinf.org/applications/pes.html).

THE H2NO POTENTIAL ENERGY SURFACE EXPLORED WITH HIGH LEVEL AB INITIO AND DENSITY FUNCTIONAL THEORY METHODS

2007 ◽  
Vol 06 (03) ◽  
pp. 549-562
Author(s):  
ABRAHAM F. JALBOUT
Keyword(s):  
Density Functional Theory ◽  
Potential Energy ◽  
Potential Energy Surface ◽  
Density Functional ◽  
Energy Surface ◽  
Hybrid Methods ◽  
Transition States ◽  
Basis Set ◽  
Functional Theory ◽  
High Level

The transition states for the H 2 NO decomposition and rearrangements mechanisms have been explored by the CBS-Q method or by density functional theory. Six transition states were located on the potential energy surface, which were explored with the Quadratic Complete Basis Set (CBS-Q) and Becke's one-parameter density functional hybrid methods. Interesting deviations between the CBS-Q results and the B1LYP density functional theory lead us to believe that further study into this system is necessary. In the efforts to further assess the stabilities of the transition states, bond order calculations were performed to measure the strength of the bonds in the transition state.

scholarly journals Three Dimensional Potential Energy Surface For The F3

2021 ◽  
Author(s):  
Jing Cao ◽  
Chunmei Hu ◽  
Hongmei Yu ◽  
Yuxuan Bai ◽  
Yanchun Li ◽  
...  
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Potential Energy Surfaces ◽  
Energy Surface ◽  
Three Dimensional ◽  
Basis Set ◽  
B Spline ◽  
Adiabatic Potential Energy Surface ◽  
High Level ◽  
Energy Surfaces

Abstract In order to study the F3 system, an accurate global adiabatic potential energy surface is reduced in the present work. The high level ab initio (MCSCF/MRCI level) methods with big basis set aVQZ are used to calculate 27690 potential energy points in MOLPRO quantum chemistry package using Jacobi coordinate. Meanwhile, B-spline fit method is used to reduce the global potential energy surface in this present work. The shallow well complexes are found in the present work when the angles θ = 30°, 60°, and 90°. Analysing the global potential energy surfaces one can get the conclusion that reactants should overcome at least 0.894 eV energy to cross transition state and reach products.

Rotational de-excitations of C3H+ (1Σ+) by collision with He: new ab initio potential energy surface and scattering calculations

2020 ◽  
Vol 494 (4) ◽  
pp. 5675-5681 ◽  
Author(s):  
Sanchit Chhabra ◽  
T J Dhilip Kumar
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Ab Initio ◽  
Cross Sections ◽  
Energy Surface ◽  
Molecular Ions ◽  
Basis Set ◽  
Rate Coefficients ◽  
Close Coupling ◽  
Collisional Rate Coefficients

ABSTRACT Molecular ions play an important role in the astrochemistry of interstellar and circumstellar media. C3H+ has been identified in the interstellar medium recently. A new potential energy surface of the C3H+–He van der Waals complex is computed using the ab initio explicitly correlated coupled cluster with the single, double and perturbative triple excitation [CCSD(T)-F12] method and the augmented correlation consistent polarized valence triple zeta (aug-cc-pVTZ) basis set. The potential presents a well of 174.6 cm−1 in linear geometry towards the H end. Calculations of pure rotational excitation cross-sections of C3H+ by He are carried out using the exact quantum mechanical close-coupling approach. Cross-sections for transitions among the rotational levels of C3H+ are computed for energies up to 600 cm−1. The cross-sections are used to obtain the collisional rate coefficients for temperatures T ≤ 100 K. Along with laboratory experiments, the results obtained in this work may be very useful for astrophysical applications to understand hydrocarbon chemistry.

Theoretical study of the Cl(2P) + SiH4 reaction: Global potential energy surface and product pair-correlated distributions. Comparison with experiment.

2021 ◽  
Author(s):  
J. Espinosa-Garcia ◽  
Jose Carlos Corchado
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Energy Surface ◽  
Theoretical Study ◽  
Title Reaction ◽  
Comparison With Experiment ◽  
Explicitly Correlated ◽  
High Level ◽  
First Time ◽  
Product Pair

For the theoretical study of the title reaction, an analytical full-dimensional potential energy surface named PES-2021 was developed for the first time, by fitting high-level explicitly-correlated ab initio data. This...

Kinetic and dynamic studies of the H3+ + CO → H2 + HCO+/HOC+ reaction on a high-level ab initio potential energy surface

2019 ◽  
Vol 151 (5) ◽  
pp. 054311 ◽  
Author(s):  
Yongfa Zhu ◽  
Li Tian ◽  
Hongwei Song ◽  
Minghui Yang
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Ab Initio ◽  
Energy Surface ◽  
Dynamic Studies ◽  
High Level

The hydrogen abstraction reaction H + C2H6 → H2(v,j) + C2H5. Part I. A full-dimensional analytical potential energy surface based on ab initio calculations

2019 ◽  
Vol 21 (24) ◽  
pp. 13347-13355 ◽  
Author(s):  
Joaquin Espinosa-Garcia ◽  
Moises Garcia-Chamorro ◽  
Jose C. Corchado
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Energy Surface ◽  
Hydrogen Abstraction ◽  
Level Structure ◽  
Valence Bond ◽  
Abstraction Reaction ◽  
Analytical Potential ◽  
High Level ◽  
Hydrogen Abstraction Reaction

Using as input data high-level structure electronic calculations, a new full-dimensional analytical potential energy surface (PES), named PES-2018, was developed for the title reaction, which is a valence bond/molecular mechanics based surface that depends on a set of adjustable parameters.

Inelastic vibrational dynamics of CS in collision with H2 using a full-dimensional potential energy surface

2018 ◽  
Vol 20 (45) ◽  
pp. 28425-28434 ◽  
Author(s):  
Benhui Yang ◽  
P. Zhang ◽  
C. Qu ◽  
P. C. Stancil ◽  
J. M. Bowman ◽  
...  
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Ab Initio ◽  
Energy Surface ◽  
Invariant Polynomial ◽  
Polynomial Method ◽  
Vibrational Dynamics ◽  
Close Coupling ◽  
High Level

A six-dimensional potential energy surface for the CS–H2 system was computed using high-level ab initio theory and fitted using a hybrid invariant polynomial method. Quantum close-coupling scattering calculations have been carried out for rovibrational quenching transitions of CS induced by H2.

Characterization of intermediates on the 1O2 + R2S potential energy surface. A high-level ab initio study

1998 ◽  
Vol 422 (1-3) ◽  
pp. 123-132 ◽  
Author(s):  
Christine Shangguan ◽  
Michael A. McAllister
Keyword(s):  
Potential Energy ◽  
Potential Energy Surface ◽  
Ab Initio ◽  
Energy Surface ◽  
Ab Initio Study ◽  
High Level
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