Difference in the Potential Energy Surfaces from the Fragment MO Method and Conventional Ab Initio SCF-MO Method. A Case of a Surface for Ring Rotation of (−)-Epicatechin Gallate Using the STO-3G Basis Set

2007 ◽  
Vol 80 (10) ◽  
pp. 1939-1941 ◽  
Author(s):  
Katsuhiro Tamura ◽  
Toshio Watanabe ◽  
Takayoshi Ishimoto ◽  
Umpei Nagashima
Keyword(s):  
Potential Energy ◽  
Ab Initio ◽  
Potential Energy Surfaces ◽  
Basis Set ◽  
Epicatechin Gallate ◽  
Ring Rotation ◽  
Energy Surfaces

scholarly journals New ab Initio Potential Energy Surfaces for the Renner-Teller Coupled 11A′ and 11A′′ States of CH2

2012 ◽  
Vol 2012 ◽  
pp. 1-12 ◽  
Author(s):  
Haitao Ma ◽  
Chunfang Zhang ◽  
Zhijun Zhang ◽  
Xiaojun Liu ◽  
Wensheng Bian
Keyword(s):  
Potential Energy ◽  
Ab Initio ◽  
Potential Energy Surfaces ◽  
Energy Levels ◽  
Electronic States ◽  
Nonlinear Least Squares ◽  
Basis Set ◽  
Least Squares Fit ◽  
Three Body ◽  
Energy Surfaces

New ab initio potential energy surfaces (PESs) for the two lowest-lying singlet 11A′ and 11A′′ electronic states of CH2, coupled by the Renner-Teller (RT) effect and meant for the spectroscopic study, are presented. The surfaces are constructed using a dual-level strategy. The internally contracted multireference configuration interaction calculations with the Davidson correction, using the aug-cc-pVQZ basis set, are employed to obtain 3042 points at the lower level. The core and core-valence correlation effects are taken into account in the ab initio calculations with a modified optimized aug-cc-pCVQZ basis set for the higher-level points. The analytical representations of these PESs, with the inclusion of the nonadiabatic RT terms, are obtained by the nonlinear least-squares fit of the calculated points to three-body expansion. Quantum dynamical calculations are performed on these PESs, and the computed vibronic energy levels for the two singlet electronic states are in excellent agreement with experiment.

scholarly journals Ab Initio Potential Energy Surfaces for Both the Ground (X̃1A′) and Excited (A∼1A′′) Electronic States of HSiBr and the Absorption and Emission Spectra of HSiBr/DSiBr

2012 ◽  
Vol 2012 ◽  
pp. 1-20 ◽  
Author(s):  
Anyang Li ◽  
Sen Lin ◽  
Daiqian Xie
Keyword(s):  
Potential Energy ◽  
Ab Initio ◽  
Potential Energy Surfaces ◽  
Vibrational Energy ◽  
Electronic States ◽  
Emission Spectra ◽  
Basis Set ◽  
Absorption And Emission ◽  
Absorption And Emission Spectra ◽  
Energy Surfaces

Ab initio potential energy surfaces for the ground (X̃1A′) and excited (A˜A′′1) electronic states of HSiBr were obtained by using the single and double excitation coupled-cluster theory with a noniterative perturbation treatment of triple excitations and the multireference configuration interaction with Davidson correction, respectively, employing an augmented correlation-consistent polarized valence quadruple zeta basis set. The calculated vibrational energy levels of HSiBr and DSiBr of the ground and excited electronic states are in excellent agreement with the available experimental band origins. In addition, the absorption and emission spectra of HSiBr and DSiBr were calculated using an efficient single Lanczos propagation method and are in good agreement with the available experimental observations.

scholarly journals Global ab initio potential energy surfaces for the O2(Σ3g−)+O2(Σ3g−) interaction

2010 ◽  
Vol 133 (12) ◽  
pp. 124311 ◽  
Author(s):  
Massimiliano Bartolomei ◽  
Estela Carmona-Novillo ◽  
Marta I. Hernández ◽  
José Campos-Martínez ◽  
Ramón Hernández-Lamoneda
Keyword(s):  
Potential Energy ◽  
Ab Initio ◽  
Potential Energy Surfaces ◽  
Energy Surfaces

Intermolecular potential energy surfaces and spectra of Ne–HCN complex from ab initio calculations

2001 ◽  
Vol 114 (2) ◽  
pp. 764 ◽  
Author(s):  
Garold Murdachaew ◽  
Alston J. Misquitta ◽  
Robert Bukowski ◽  
Krzysztof Szalewicz
Keyword(s):  
Potential Energy ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Potential Energy Surfaces ◽  
Intermolecular Potential ◽  
Energy Surfaces
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