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Computation of Atmospheric Concentrations of Molecular Clusters from ab initio Thermochemistry
Published on: April 8, 2020
A pseudopotential-based composite method: the relativistic pseudopotential correlation consistent composite approach
Marie L Laury1, Nathan J DeYonker, Wanyi Jiang
1Center for Advanced Scientific Computing and Modeling (CASCaM), Department of Chemistry, University of North Texas, Denton, Texas 76203-5070, USA.
The Journal of Chemical Physics
|December 14, 2011
Summary
The relativistic pseudopotential correlation consistent composite approach (rp-ccCA) accurately calculates thermodynamic data for heavy elements. This method offers significant time savings and achieves chemical accuracy for transition metal species.
Area of Science:
- Computational Chemistry
- Quantum Chemistry
- Chemical Thermodynamics
Background:
- The correlation consistent composite approach (ccCA) is a reliable method for calculating energetic and thermodynamic data.
- Extending ccCA to heavier elements, especially transition metals, requires efficient computational strategies.
Purpose of the Study:
- To develop and validate a relativistic pseudopotential-based ccCA (rp-ccCA) for accurate thermodynamic calculations.
- To assess the performance of rp-ccCA for main group elements (Ga-Kr) and 4d transition metals.
Main Methods:
- Formulation of the relativistic pseudopotential ccCA (rp-ccCA) method.
- Application of rp-ccCA to G3/05 set molecules containing 4p elements (Ga-Kr).
- Testing rp-ccCA on 4d transition metal-containing molecules, including diatomics and Mo(CO)6.
Main Results:
- rp-ccCA achieved a 32.5% time saving compared to all-electron ccCA.
- For 4p elements, rp-ccCA yielded a mean absolute deviation of 0.89 kcal/mol from experimental data.
- For 4d transition metals, rp-ccCA obtained enthalpies of formation with a mean absolute deviation of 2.89 kcal/mol, within chemical accuracy.
Conclusions:
- rp-ccCA is an effective and computationally efficient method for calculating thermodynamic properties of heavy main group elements and transition metals.
- The rp-ccCA method provides results that meet or exceed chemical accuracy for the studied systems.
- This approach enables accurate predictions for molecules containing elements from Ga-Kr and Y-Cd.
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