Representing the potential-energy surface of protonated water clusters by high-dimensional neural network potentials

2015 ◽  
Vol 17 (13) ◽  
pp. 8356-8371 ◽  
Author(s):  
Suresh Kondati Natarajan ◽  
Tobias Morawietz ◽  
Jörg Behler

We report a reactive neural network potential for protonated water clusters that accurately represents the density-functional theory potential-energy surface.

Author(s):  
Ashot S. Mkhitaryan ◽  
Zakar K. Papanyan ◽  
Liana S. Gabrielyan ◽  
Shiraz A. Markarian

The quantum chemical study of the hydration of diethyl sulfone was performed by using Gaussian 09 software package. The conformational analysis of the isolated molecule of diethyl sulfone is performed by the restricted Hartree-Fock (RHF) and the density functional theory (DFT/B3PW91) methods with 6-311++G(d,p) extended basis set. The analysis of the potential energy surface revealed the existence of four stable conformers of diethyl sulfone with different degrees of degeneracy. The nature of stationary points on the potential energy surface is verified by the complete gas phase optimization and the vibrational analysis. The global minimum is the conformer with two (CCSC) dihedral angles equal 180°. The fractional population distribution of different conformers is determined by Boltzmann distribution. The average energy of the diethyl sulfone molecule in vacuum is calculated. To account the effect of solvent the self-consistent reaction field (SCRF) method, particularly, solvent model based on electron density (SMD), was employed. It is shown, that solvent affects on the relative population of conformers. The thermodynamic parameters, in particular enthalpy, for the conformers of diethyl sulfone are determined both in the gas phase and in the aqueous solution. The average energy of diethyl sulfone in water is calculated. It is shown, that although the dissolution of crystalline diethyl sulfone in water is an endothermic process, the hydration of diethyl sulfone molecules occurs with the release of heat. The heat of dissolution of diethyl sulfone calculated by the density functional theory is consistent with the experimental data.


2007 ◽  
Vol 06 (03) ◽  
pp. 549-562
Author(s):  
ABRAHAM F. JALBOUT

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.


2017 ◽  
Vol 70 (4) ◽  
pp. 362 ◽  
Author(s):  
Young J. Hong ◽  
Dean J. Tantillo

An energetically viable (on the basis of results from density functional theory computations) pathway to the diterpene variediene is described. Only one of the three secondary carbocations along this pathway is predicted to be a minimum on the potential energy surface.


2010 ◽  
Vol 133 (5) ◽  
pp. 054303 ◽  
Author(s):  
Patricia Barragán ◽  
Rita Prosmiti ◽  
Octavio Roncero ◽  
Alfredo Aguado ◽  
Pablo Villarreal ◽  
...  

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