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

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

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>

Scaling factors for vibrational frequencies and zero-point vibrational energies of some recently developed exchange-correlation functionals

2006 ◽  
Vol 760 (1-3) ◽  
pp. 189-192 ◽  
Author(s):  
Yuthana Tantirungrotechai ◽  
Ketthip Phanasant ◽  
Supacharee Roddecha ◽  
Panida Surawatanawong ◽  
Vallaya Sutthikhum ◽  
...  
Keyword(s):  
Zero Point ◽  
Vibrational Frequencies ◽  
Scaling Factors ◽  
Exchange Correlation ◽  
Vibrational Energies

Charge distributions and chemical effects. XXIV. On the role of vibrational energies in determining molecular stabilities

1981 ◽  
Vol 59 (9) ◽  
pp. 1381-1387 ◽  
Author(s):  
Sándor Fliszár ◽  
J.-L. Cantara
Keyword(s):  
Conformational Changes ◽  
Vibrational Energy ◽  
Heat Content ◽  
Zero Point ◽  
Enthalpies Of Formation ◽  
Chemical Binding ◽  
Nuclear Magnetic Resonance Spectra ◽  
Molecular Stability ◽  
Coulomb Type ◽  
Vibrational Energies

A simple equation has been derived for calculating accurate ZPE + HT − H0 (zero-point and heat content) energies of saturated hydrocarbons from their enthalpies of formation and carbon-13 nuclear magnetic resonance spectra. Applications to conformational analysis indicate a near invariance of vibrational energies with respect to chair–boat conformational changes of the cyclohexane ring, the loss in molecular stability arising then from a weakening of the chemical binding due to a reorganization of the electronic charges. The origin of the destabilizing effect of butane gauche interactions is found, in the cyclohexane series, in a weakening of the chemical binding (∼1.85 kcal/mol) which is partially compensated by a lowering (∼0.85 kcal/mol) vibrational energy, thus offering an explanation for the loss in molecular stability of ∼1.00 kcal/mol for one gauche interaction without invoking Coulomb-type repulsions between non-bonded atoms. Calculated enthalpies of formation are presentd for a number of cycloalkanes.

scholarly journals Charge distributions and chemical effects. XXIX. On the vibrational energies of chair and boat cyclohexane

1982 ◽  
Vol 60 (11) ◽  
pp. 1347-1351 ◽  
Author(s):  
J. P. Huvenne ◽  
G. Vergoten ◽  
G. Fleury ◽  
S. Odiot ◽  
S. Fliszár
Keyword(s):  
Force Field ◽  
Conformational Changes ◽  
Vibrational Energy ◽  
Zero Point ◽  
Local Symmetry ◽  
Cyclohexane Ring ◽  
Force Field Calculations ◽  
Similar Nature ◽  
Chemical Effects ◽  
Vibrational Energies

Local symmetry force field calculations are presented for the chair and boat forms of cyclohexane and the assignments of frequencies are given. The calculated zero-point and thermal vibrational energies indicate a near invariance of total vibrational energy with respect to chair–boat conformational changes of the cyclohexane ring, thus confirming results of similar nature derived from earlier theoretical thermochemical analyses.

Zero-point vibrational energies of spherical Coulomb crystals

2009 ◽  
Vol 130 (9) ◽  
pp. 094902 ◽  
Author(s):  
Jerzy Cioslowski ◽  
Ewa Grzebielucha
Keyword(s):  
Zero Point ◽  
Vibrational Energies ◽  
Coulomb Crystals

A comparison of ab initio quantum-mechanical and experimental D0 binding energies of eleven H-bonded and eleven dispersion-bound complexes

2015 ◽  
Vol 17 (40) ◽  
pp. 26645-26652 ◽  
Author(s):  
Susanta Haldar ◽  
Ramachandran Gnanasekaran ◽  
Pavel Hobza
Keyword(s):  
Ab Initio ◽  
Zero Point ◽  
Binding Energies ◽  
Quantum Mechanical ◽  
Interaction Energies ◽  
Dissociation Energies ◽  
Vibrational Energies

Dissociation energies (D0) of 11 H-bonded and 11 dispersion-bound complexes were calculated as the sum of interaction energies and the change of zero-point vibrational energies (ΔZPVE).

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