Refinement of Nonbonding Interaction Potential Parameters for Methane on the Basis of the Pair Potential Obtained by MP3/6-311G(3d,3p)-Level ab Initio Molecular Orbital Calculations: The Anisotropy of H/H Interaction

1994 ◽  
Vol 98 (7) ◽  
pp. 1830-1833 ◽  
Author(s):  
Seiji Tsuzuki ◽  
Tadafumi Uchimaru ◽  
Kazutoshi Tanabe ◽  
Satoru Kuwajima
Keyword(s):  
Ab Initio ◽  
Molecular Orbital ◽  
Interaction Potential ◽  
Pair Potential ◽  
Molecular Orbital Calculations ◽  
Nonbonding Interaction ◽  
Potential Parameters

An Intermolecular Potential Function for Cyclen-Water Derived from Ab-Initio Molecular Orbital Calculations

1985 ◽  
Vol 40 (6) ◽  
pp. 644-648 ◽  
Author(s):  
Supot V. Hannongbua ◽  
Bernd M. Rode
Keyword(s):  
Ab Initio ◽  
Potential Function ◽  
Molecular Orbital ◽  
Energy Surface ◽  
Pair Potential ◽  
Intermolecular Potential ◽  
Molecular Orbital Calculations ◽  
Atomic Charges ◽  
Analytical Potential

An interaction pair potential function for 1,4,7,10-tetraaza-cyclododecane (cyclen) and water has been derived from ab-initio molecular orbital computations. The 250 computed points of the energy surface for the water-cyclen interaction have been fitted with an analytical potential of the form where A, B. C, and D are constants, and qi, and qj are the atomic charges of the i-th atom of water and the j-th atom of cyclen at infinite separation.

A pairwise additivity scheme for conformational energies of substituted ethanes

1975 ◽  
Vol 343 (1632) ◽  
pp. 1-10 ◽  
Keyword(s):  
Large Deviations ◽  
Ab Initio ◽  
Dihedral Angle ◽  
Molecular Orbital ◽  
Methyl Groups ◽  
Molecular Orbital Calculations ◽  
Linear Combinations ◽  
Strongly Interacting ◽  
Conformational Energies

Ab initio molecular orbital calculations are used to explore additivity in the conformational energies of poly-substituted ethanes in terms of conformational energies of ethane and appropriate mono- and 1,2-di-substituted derivatives. Such relations would allow complex calculations for poly-substituted ethanes to be replaced by much simpler ones on a small number of parent molecules. General expressions for the linear combinations are derived from the assumption that interactions between vicinal substituents are pairwise additive and depend only on the vicinal dihedral angle. The additivity scheme is tested for 15 ethanes, di-, tri- or tetrasubstituted by cyano and methyl groups and for a smaller number of fluoroethanes. Additivity applies to within 0.1- 0.3 k J mol -1 in the methylethanes and mostly to within about 0.7- 0.8 kJ mol -1 in cyanoethanes. Large deviations are found among the geminally substituted fluoroethanes. It is suggested that the additivity approximation is most successful in the absence of strongly interacting geminal groups. Predictions are made of conformational energies of ten hexa(cyano- and methyl-) substituted ethanes.

Gas-Phase Tautomerism in the Triazoles and Tetrazoles: A Study by Photoelectron Spectroscopy and ab Initio Molecular Orbital Calculations

1981 ◽  
Vol 36 (11) ◽  
pp. 1246-1252 ◽  
Author(s):  
Michael H. Palmer ◽  
Isobel Simpson ◽  
J. Ross Wheeler
Keyword(s):  
Ab Initio ◽  
Gas Phase ◽  
Molecular Orbital ◽  
Photoelectron Spectroscopy ◽  
Relative Stability ◽  
Photoelectron Spectra ◽  
Equilibrium Geometry ◽  
Molecular Orbital Calculations ◽  
Methyl Derivatives

The photoelectron spectra of the tautomeric 1,2,3,- and 1,2,4-triazole and 1,2,3,4-tetrazole systems have been compared with the corresponding N-methyl derivatives. The dominant tautomers in the gas phase have been identified as 2 H-1,2,3-triazole, 1 H-1,2,4-triazole and 2H-tetrazole.Full optimisation of the equilibrium geometry by ab initio molecular orbital methods leads to the same conclusions, for relative stability of the tautomers in each of the triazoles, but the calculations wrongly predict the tetrazole tautomerism.

Prediction of Charge Transport Properties of Molecular Materials by Ab Initio Molecular Orbital Calculations

2000 ◽  
Vol 660 ◽  
Author(s):  
Wataru Sotoyama ◽  
Tomoaki Hayano ◽  
Hiroyuki Sato ◽  
Azuma Matsuura ◽  
Toshiaki Narusawa
Keyword(s):  
Charge Transport ◽  
Ab Initio ◽  
Molecular Orbital ◽  
Electron Mobility ◽  
Molecular Orbital Calculations ◽  
Molecular Materials ◽  
Structural Reorganization ◽  
Charge Hopping ◽  
Reorganization Energies ◽  
A Charge

ABSTRACTWe developed a method to predict the charge transport (CT) type (hole or electron) in molecular materials that uses molecular orbital calculations. The hole-and-electron-mobility ratios of molecular materials were calculated based on molecular structural reorganization energies in a charge hopping process. The CT types predicted from the calculated mobility ratios agreed with those experimentally obtained in seven of the eight model molecules.

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