Computational s-Block Thermochemistry with the Correlation Consistent Composite Approach

Description:

Article discussing research on computational s-block thermochemistry with the correlation consistent composite approach, which has been shown to accurately compute gas-phase enthalapies of formation for alkali and alkaline earth metal oxides and hydroxides.

Creator(s):
Creation Date: October 3, 2007
Partner(s):
UNT College of Arts and Sciences
Collection(s):
UNT Scholarly Works
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Total Uses: 100
Past 30 days: 2
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Creator (Author):
DeYonker, Nathan J.

University of North Texas

Creator (Author):
Ho, Dustin S.

University of North Texas

Creator (Author):
Wilson, Angela K.

University of North Texas

Creator (Author):
Cundari, Thomas R., 1964-

University of North Texas

Publisher Info:
Publisher Name: American Chemical Society
Place of Publication: [Washington, DC]
Date(s):
  • Creation: October 3, 2007
Description:

Article discussing research on computational s-block thermochemistry with the correlation consistent composite approach, which has been shown to accurately compute gas-phase enthalapies of formation for alkali and alkaline earth metal oxides and hydroxides.

Degree:
Department: Chemistry
Note:

Reprinted with permission from the Journal of Physical Chemistry A. Copyright 2007 American Chemical Society.

Note:

Abstract: The correlation consistent composite approach (ccCA) is a model chemistry that has been shown to accurately compute gas-phase enthalpies of formation for alkali and alkaline earth metal oxides and hydroxides (Ho, D.S.; DeYonker, N.J.; Wilson, A.K.; Cundari, T.R., J. Phys. Chem. A 2006, 110, 9767). The ccCA results contrast to more widely used model chemistries where calculated enthalpies of formation for such species can be in error by up to 90 kcal molˉ¹. In this study, the authors have applied ccCA to a more general set of 42 s-block molecules and compared the ccCA ∆Hf values to values obtained using the G3 and G3B model chemistries. Included in this training set are water complexes such as Na(H₂O)n⁺ where n = 1 - 4, dimers and trimers of ionic compounds such as (LiCl)₂ and (LiCl)₃, and the largest ccCA computation to date: Be-(acac)₂, BeC₁₀H₁₄O₄. Problems with the G3 model chemistries seem to be isolated to metal-oxygen bonded systems and Be-containing systems, as G3 and G3B still perform quite well with a 2.7 and 2.6 kcal mol⁻¹ mean absolute deviation (MAD), respectively, for gas-phase enthalpies of formation. The MAD of the ccCA is only 2.2 kcal mol⁻¹ for enthalpies of formation (∆ Hf) for all compounds studied herein. While this MAD is roughly double that found for a ccCA study of >350 main group (i.e., p-block) compounds, it is commensurate with typical experimental uncertainties for s-block complexes. Some molecules where G3/G3B and ccCA computed ∆Hf values deviate significantly from experiment, such as (LiCl)₃, NaCN, and MgF, are inviting candidates for new experimental and high-level theoretical studies.

Physical Description:

5 p.

Language(s):
Subject(s):
Keyword(s): thermodynamics | earth metal oxides | earth metal hydroxides | alkali | alkaline
Source: Journal of Physical Chemistry A, 2007, Washington DC: American Chemical Society
Partner:
UNT College of Arts and Sciences
Collection:
UNT Scholarly Works
Identifier:
  • DOI: 10.1021/jp0736241 |
  • ARK: ark:/67531/metadc77174
Resource Type: Article
Format: Text
Rights:
Access: Public
Citation:
Publication Title: Journal of Physical Chemistry A
Volume: 111
Page Start: 10776
Page End: 10780
Pages: 5
Peer Reviewed: Yes