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Application of the PM6 method to modeling the solid state.

Stewart JJ - J Mol Model (2008)

Bottom Line: The applicability of the recently developed PM6 method for modeling various properties of a wide range of organic and inorganic crystalline solids has been investigated.Although the geometries of most systems examined were reproduced with good accuracy, severe errors were found in the predicted structures of a small number of solids.The origin of these errors was investigated, and a strategy for improving the method proposed.

View Article: PubMed Central - PubMed

Affiliation: Stewart Computational Chemistry, 15210 Paddington Circle, Colorado Springs, CO 80921, USA. MrMOPAC@OpenMOPAC.net

ABSTRACT
The applicability of the recently developed PM6 method for modeling various properties of a wide range of organic and inorganic crystalline solids has been investigated. Although the geometries of most systems examined were reproduced with good accuracy, severe errors were found in the predicted structures of a small number of solids. The origin of these errors was investigated, and a strategy for improving the method proposed.

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Effect of truncation on apparent position of charges. For a set of charges (black), the position used in evaluating the electrostatic interactions is shown in green
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Fig2: Effect of truncation on apparent position of charges. For a set of charges (black), the position used in evaluating the electrostatic interactions is shown in green

Mentions: For atoms that are at a distance less than some predefined value, 2/3C, the exact DSK approximation is used. Between 2/3C and 4/3C, the EID to be used in Eq. 4 would be reduced as shown in Eq. 5. 5\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$R_{AB}^\prime = 2R_{AB} - C/3 - \frac{{3R_{AB}^2 }}{{4C}}$$\end{document}, and at distances greater than 4/3C the value of the EID would be a constant C. The effect of these changes when applied to an example set of charges is illustrated in Fig. 2, with the original charges shown in black, and the locations of the charges that would be used in evaluating the electrostatic potential shown in green.Fig. 2


Application of the PM6 method to modeling the solid state.

Stewart JJ - J Mol Model (2008)

Effect of truncation on apparent position of charges. For a set of charges (black), the position used in evaluating the electrostatic interactions is shown in green
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2386531&req=5

Fig2: Effect of truncation on apparent position of charges. For a set of charges (black), the position used in evaluating the electrostatic interactions is shown in green
Mentions: For atoms that are at a distance less than some predefined value, 2/3C, the exact DSK approximation is used. Between 2/3C and 4/3C, the EID to be used in Eq. 4 would be reduced as shown in Eq. 5. 5\documentclass[12pt]{minimal}\usepackage{amsmath}\usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy}\usepackage{mathrsfs}\usepackage{upgreek}\setlength{\oddsidemargin}{-69pt}\begin{document}$$R_{AB}^\prime = 2R_{AB} - C/3 - \frac{{3R_{AB}^2 }}{{4C}}$$\end{document}, and at distances greater than 4/3C the value of the EID would be a constant C. The effect of these changes when applied to an example set of charges is illustrated in Fig. 2, with the original charges shown in black, and the locations of the charges that would be used in evaluating the electrostatic potential shown in green.Fig. 2

Bottom Line: The applicability of the recently developed PM6 method for modeling various properties of a wide range of organic and inorganic crystalline solids has been investigated.Although the geometries of most systems examined were reproduced with good accuracy, severe errors were found in the predicted structures of a small number of solids.The origin of these errors was investigated, and a strategy for improving the method proposed.

View Article: PubMed Central - PubMed

Affiliation: Stewart Computational Chemistry, 15210 Paddington Circle, Colorado Springs, CO 80921, USA. MrMOPAC@OpenMOPAC.net

ABSTRACT
The applicability of the recently developed PM6 method for modeling various properties of a wide range of organic and inorganic crystalline solids has been investigated. Although the geometries of most systems examined were reproduced with good accuracy, severe errors were found in the predicted structures of a small number of solids. The origin of these errors was investigated, and a strategy for improving the method proposed.

Show MeSH