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

Kód výsledku v 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>

Výsledek na webu

<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>

Jazyk výsledku

angličtina

Název v původním jazyce

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

Popis výsledku v původním jazyce

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

Název v anglickém jazyce

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

Popis výsledku anglicky

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

Druh

J_x - Nezařazeno - Článek v odborném periodiku (Jimp, Jsc a Jost)

CEP obor

CF - Fyzikální chemie a teoretická chemie

OECD FORD obor

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Projekt

Výsledek vznikl pri realizaci vícero projektů. Více informací v záložce Projekty.

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2012

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Chemical Engineering Data

ISSN

0021-9568

e-ISSN

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Svazek periodika

57

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

6

Strana od-do

227-232

Kód UT WoS článku

000298978900035

EID výsledku v databázi Scopus

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