Modelling organic crystal structures using distributed multipole and polarizability-based model intermolecular potentials

2010 ◽  
Vol 12 (30) ◽  
pp. 8478 ◽  
Author(s):  
Sarah L. Price ◽  
Maurice Leslie ◽  
Gareth W. A. Welch ◽  
Matthew Habgood ◽  
Louise S. Price ◽  
...  
Keyword(s):  
Crystal Structures ◽  
Organic Crystal ◽  
Intermolecular Potentials

Deriving intermolecular potentials for predicting the crystal structures of polar molecules

1996 ◽  
Vol 73 (1) ◽  
pp. 117-125 ◽  
Author(s):  
David S. Coombes
Keyword(s):  
Crystal Structures ◽  
Polar Molecules ◽  
Intermolecular Potentials

Use of Atom-Atom Potentials in the Determination of Organic Crystal Structures

1979 ◽  
Vol 50 (1) ◽  
pp. 175-178 ◽  
Author(s):  
S. Ramdas
Keyword(s):  
Crystal Structures ◽  
Organic Crystal

scholarly journals Validation of experimental molecular crystal structures with dispersion-corrected density functional theory calculations

2010 ◽  
Vol 66 (5) ◽  
pp. 544-558 ◽  
Author(s):  
Jacco van de Streek ◽  
Marcus A. Neumann
Keyword(s):  
Density Functional Theory ◽  
Crystal Structures ◽  
Density Functional ◽  
Unit Cell ◽  
Organic Crystal ◽  
Large Temperature ◽  
Unit Cell Parameters ◽  
Functional Theory ◽  
Cell Parameters ◽  
Experimental Crystal

This paper describes the validation of a dispersion-corrected density functional theory (d-DFT) method for the purpose of assessing the correctness of experimental organic crystal structures and enhancing the information content of purely experimental data. 241 experimental organic crystal structures from the August 2008 issue of Acta Cryst. Section E were energy-minimized in full, including unit-cell parameters. The differences between the experimental and the minimized crystal structures were subjected to statistical analysis. The r.m.s. Cartesian displacement excluding H atoms upon energy minimization with flexible unit-cell parameters is selected as a pertinent indicator of the correctness of a crystal structure. All 241 experimental crystal structures are reproduced very well: the average r.m.s. Cartesian displacement for the 241 crystal structures, including 16 disordered structures, is only 0.095 Å (0.084 Å for the 225 ordered structures). R.m.s. Cartesian displacements above 0.25 Å either indicate incorrect experimental crystal structures or reveal interesting structural features such as exceptionally large temperature effects, incorrectly modelled disorder or symmetry breaking H atoms. After validation, the method is applied to nine examples that are known to be ambiguous or subtly incorrect.

Aromatic ring–aliphatic ring stacking in organic crystal structures

2002 ◽  
Vol 5 (1) ◽  
pp. 3-8 ◽  
Author(s):  
P.K.C. Paul
Keyword(s):  
Crystal Structures ◽  
Aromatic Ring ◽  
Organic Crystal

Knowledge-based model of hydrogen-bonding propensity in organic crystals

2007 ◽  
Vol 63 (5) ◽  
pp. 768-782 ◽  
Author(s):  
Peter T. A. Galek ◽  
László Fábián ◽  
W. D. Samuel Motherwell ◽  
Frank H. Allen ◽  
Neil Feeder
Keyword(s):  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Crystal Structures ◽  
Three Dimensional ◽  
Chemical Properties ◽  
Organic Crystal ◽  
Training Data ◽  
Survey Method ◽  
Statistical Validation ◽  
Knowledge Based

A new method is presented to predict which donors and acceptors form hydrogen bonds in a crystal structure, based on the statistical analysis of hydrogen bonds in the Cambridge Structural Database (CSD). The method is named the logit hydrogen-bonding propensity (LHP) model. The approach has a potential application in identifying both likely and unusual hydrogen bonding, which can help to rationalize stable and metastable crystalline forms, of relevance to drug development in the pharmaceutical industry. Whilst polymorph prediction techniques are widely used, the LHP model is knowledge-based and is not restricted by the computational issues of polymorph prediction, and as such may form a valuable precursor to polymorph screening. Model construction applies logistic regression, using training data obtained with a new survey method based on the CSD system. The survey categorizes the hydrogen bonds and extracts model parameter values using descriptive structural and chemical properties from three-dimensional organic crystal structures. LHP predictions from a fitted model are made using two-dimensional observables alone. In the initial cases analysed, the model is highly accurate, achieving ∼ 90% correct classification of both observed hydrogen bonds and non-interacting donor–acceptor pairs. Extensive statistical validation shows the LHP model to be robust across a range of small-molecule organic crystal structures.

Which organic crystal structures are predictable by lattice energy minimisation?

CrystEngComm ◽  
2001 ◽  
Vol 3 (44) ◽  
pp. 178-212 ◽  
Author(s):  
Theresa Beyer ◽  
Thomas Lewis ◽  
Sarah L. Price
Keyword(s):  
Crystal Structures ◽  
Lattice Energy ◽  
Organic Crystal ◽  
Energy Minimisation
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