Topological Approaches to Intermolecular Interactions

26-28 June 2013 - Paris

Workshop on "Topological approaches to intermolecular interactions"

Quantum Chemical Topology: on Bonds and Force Fields

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Abstract

Quantum Chemical Topology (QCT)[1,2] is an umbrella method that includes QTAIM[3,4] as a special case. The central idea of QCT is to partition through a gradient vector field, and apply the language and insights of dynamical systems. This talk has two distinct parts (that could be unified in future work).

The first part[5] discusses how to draw a molecule from a molecular wave function. The spatial distribution of atoms in a molecule in the form of chemical graphs is obtained for a set of molecules, using their corresponding domain-averaged exchange-correlation energies (Vxc). Conveniently, such energies are transferable (for 1,n interactions in saturated linear hydrocarbons) and can provide an accurate estimation of the covalent-like contribution between pairs of given interacting topological atoms A and B.

The second part focuses on the electrostatic interaction in a novel topological force field for biomolecular modeling. Topological atoms are boxes with a particular shape and a finite volume. If the coordinates change then the shapes of the atoms change too, as well as their multipole moments. This complex relationship is captured by a machine learning technique called kriging. Here I will explore how these ideas6 can be used to enhance the realism of the electrostatic energy, [7,8] and put polarisation and charge transfer on the same footing, without having a polarisation catastrophe.

[1] Popelier, P. L. A.; Brémond, É. A. G. Int.J.Quant.Chem. 2009, 109, 2542.
[2] Popelier, P. L. A. In Structure and Bonding. Intermolecular Forces and Clusters, Ed, D.J.Wales; Springer: Heidelberg, Germany, 2005; Vol. 115, p 1.
[3] Bader, R. F. W. Atoms in Molecules. A Quantum Theory.; Oxford Univ. Press, Great Britain, 1990.
[4] Popelier, P. L. A. Atoms in Molecules. An Introduction.; Pearson Education: London, Great Britain, 2000.
[5] Garcia-Revilla, M.; Francisco, E.; Popelier, P.L.A. ; Martin-Pendas, A. M. ChemPhysChem 2013, 14, 1211.
[6] Popelier, P. L. A. AIP Conf.Proc. 2012, 1456, 261.
[7] Mills, M. J. L.; Popelier, P. L. A. Theor.Chem.Acc. 2012, 131, 1137.
[8] Kandathil, S. M.; Fletcher, T. L.; Yuan, Y.; Knowles, J.; Popelier, P. L. A. J.Comput.Chem. 2013, in press, DOI: 10.1002/jcc.23333.


Speaker(s) : Paul Popelier, Manchester Institute of Biotechnology (MIB) and School of Chemistry University of Manchester, Great Britain
Public : Tous
Date : June 27 2013
Place : Paris