Dispersion Interactions in DFT and Application to Molecular Crystal-Structure Prediction

Who: Erin Johnson, Dalhousie University, Department of Chemistry, Halifax (NS), Canada.

When: Nov 11 2019, 11:30am – Join us at 11:15am to meet the speaker and to have a coffee

Where: D’Iorio Hall 214


The exchange-hole dipole moment (XDM) method is a density-functional model of London dispersion based upon second-order perturbation theory. The XDM dispersion coefficients are non-empirical and depend directly on the electron density and related properties, allowing variation of the atomic dispersion coefficients with changing chemical environment. XDM offers simultaneous high accuracy for a diverse range of chemical systems, such as intermolecular complexes, layered materials, surface adsorption, and molecular crystals. In this talk, recent applications of XDM will be presented, with a focus on the use of low-cost and composite approaches for molecular crystal-structure prediction (CSP). In particular, the application of composite methods to chiral helicenes, which have applications in organic electronics, and to selected pharmaceutical compounds will be illustrated. Finally, the effect of the density-functional delocalisation error on CSP is highlighted for organic acid-base co-crystals.


Erin is currently the Herzberg-Becke Chair in Theoretical Chemistry at Dalhousie University, in Halifax. Most recently, Erin was awarded the 2019 E.W.R. Steacie Memorial Fellowship from NSERC. Erin obtained her B.Sc. in Chemistry at Carleton University.  She then worked with two pioneers in Density Fuctional Theory for her Ph.D. and Post-doc that are well known for the famous B3LYP DFT method. For her Ph.D. she worked with famed theoretical chemist Axel Becke (the ‘B’ in B3LYP) at Queen’s University and for her NSERC Post-doc she worked with Weitao Yang at Duke University (the ‘Y’ in B3LYP).  Erin’s current research interests include the development and applications of density-functional theory for the study of electronic structure. Current applications include non-covalent interactions, molecular crystals, layered solids, electrides, and organometallic complexes.

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