Evaluation of accuracy of ideal-gas heat capacity and entropy calculations by DFT for rigid molecules

Result code in IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F60461373%3A22340%2F12%3A43870060" target="_blank" >RIV/60461373:22340/12:43870060 - isvavai.cz</a>
Result on the web
<a href="http://pubs.acs.org/doi/abs/10.1021/je201095b" target="_blank" >http://pubs.acs.org/doi/abs/10.1021/je201095b</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1021/je201095b" target="_blank" >10.1021/je201095b</a>

Result language
angličtina
Original language name
Evaluation of accuracy of ideal-gas heat capacity and entropy calculations by DFT for rigid molecules
Original language description
Quantum mechanical calculations, coupled with statistical thermodynamics, provide a means to obtain thermodynamic properties of ideal gas. In this work, we performed DFT and statistical thermodynamic calculations of ideal gas heat capacities and entropies for a set of 79 rigid molecules, which do not contain large amplitude motions, such as internal rotations or ring puckering, and for which reliable reference data were found in the literature. The effect of the size of basis sets and scale factors wassystematically examined and statistically evaluated. The absolute average relative deviations of the heat capacities and entropies calculated using unscaled harmonic frequencies from reference values were less than 2.5 % for all the basis sets studied. Both heat capacities and entropies were, however, systematically underestimated and the deviations of heat capacities showed a significant temperature dependence with a maximum deviation near ambient temperatures. Scaling the calculated fr
Czech name
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Czech description
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Type
J<sub>x</sub> - Unclassified - Peer-reviewed scientific article (Jimp, Jsc and Jost)
CEP classification
CF - Physical chemistry and theoretical chemistry
OECD FORD branch
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Project
Result was created during the realization of more than one project. More information in the Projects tab.
Continuities
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year
2012
Confidentiality
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

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