Automatic generation of force fields and property surfaces for use in variational vibrational calculations of anharmonic vibrational energies and zero-point vibrational averaged properties

2006 ◽  
Vol 125 (12) ◽  
pp. 124108 ◽  
Author(s):  
Jacob Kongsted ◽  
Ove Christiansen
Keyword(s):  
Force Fields ◽  
Zero Point ◽  
Automatic Generation ◽  
Vibrational Energies

Charge distributions and chemical effects. XXXI. Molecular energies of ethylenic compounds

1983 ◽  
Vol 61 (1) ◽  
pp. 197-205 ◽  
Author(s):  
M.-T. Béraldin ◽  
S. Fliszâr
Keyword(s):  
Zero Point ◽  
Enthalpies Of Formation ◽  
Average Deviation ◽  
Bond Forming ◽  
Chemical Effects ◽  
Nuclear Magnetic Resonance Spectra ◽  
Energy Formula ◽  
Standard Enthalpies Of Formation ◽  
Vibrational Energies ◽  
Proper Consideration

The energy formula describing bond contributions in terms of the charges carried by the bond-forming atoms is applied to ethylenic compounds. It is shown in what manner σ and π electrons can be treated within the framework of the bond energy theory giving the atomization energy of the vibrationless molecule at 0 K. Proper consideration of zero-point and thermal vibrational energies leads to standard enthalpies of formation. These calculations, which are carried out on the basis of, 13C nuclear magnetic resonance spectra, agree with their experimental counterparts, within experimental uncertainties (~0.3 kcal mol−1 average deviation).

Estimation, Computation, and Experimental Correction of Molecular Zero-Point Vibrational Energies

2005 ◽  
Vol 109 (30) ◽  
pp. 6779-6789 ◽  
Author(s):  
Gábor I. Csonka ◽  
Adrienn Ruzsinszky ◽  
John P. Perdew
Keyword(s):  
Zero Point ◽  
Vibrational Energies

Anharmonic zero point vibrational energies: Tipping the scales in accurate thermochemistry calculations?

2013 ◽  
Vol 138 (4) ◽  
pp. 044311 ◽  
Author(s):  
Florian Pfeiffer ◽  
Guntram Rauhut ◽  
David Feller ◽  
Kirk A. Peterson
Keyword(s):  
Zero Point ◽  
Vibrational Energies

Calculations on the rZ-Structure of Dimethylsulfoxide

1978 ◽  
Vol 33 (7) ◽  
pp. 842-847 ◽  
Author(s):  
V. Typke
Keyword(s):  
Force Fields ◽  
Zero Point ◽  
Calculation Scheme ◽  
Standard Errors ◽  
Methyl Groups ◽  
Average Structure ◽  
Different Types ◽  
The Asymmetry

On the basis of three different force fields the zero point average structure of dimethylsulfoxide has been calculated. Three different types of calculation were performed. It is found that the different force fields virtually do not affect the resulting parameters while the results from different types of calculation agree within three times the standard errors. The asymmetry of the methyl groups found with the calculation scheme of the rs-structure is also present in the average structure.

scholarly journals The Quest to Uncover the Nature of Benzonitrile Anion

2019 ◽  
Author(s):  
Sahil Gulania ◽  
Thomas-C. Jagau ◽  
Andrei Sanov ◽  
Anna I. Krylov
Keyword(s):  
Cross Sections ◽  
Zero Point ◽  
Bound State ◽  
Coupled Cluster ◽  
Equilibrium Geometry ◽  
Electronic Structure Methods ◽  
Condon Factors ◽  
Vibrational Energies ◽  
High Level ◽  
Franck Condon

<div><div><div><p>Anionic states of benzonitrile are investigated by high-level electronic structure methods. The calculations using equation-of-motion coupled-cluster theory for electron-attached states confirm earlier conclusions drawn from the photodetachment experiments that the ground state of the anion is the valence <sup>2</sup>B<sub>1</sub> state, while the dipole bound state lies adiabatically ~0.1 eV above. Inclusion of triple excitations and zero-point vibrational energies is important for recovering relative state ordering. The computed Franck–Condon factors and photodetachment cross-sections further confirm that the observed photodetachment spectrum originates from the valence anion. The valence anion is electronically bound at its equilibrium geometry, but is metastable at the equilibrium geometry of the neutral. The dipole-bound state, which is the only bound anionic state at the neutral geometry, may serve as a gateway state for capturing the electron. Thus, the emerging mechanistic picture entails electron capture via dipole bound state, followed by non-adiabatic relaxation forming valence anion.</p></div></div></div>

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