8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

Thu 811:10-14:00P7.55Identifying interfacial molecules of arbitrarily shapedphasesSofia Kantorovich, 1 Marcello Sega, 2 Pal Jedlovszky, 3 and Miguel Jorge 41 Ural State University, Lenin av. 51, 620083, Ekaterinburg, Russian Federation2 ICP / University of Stuttgart, Stuttgart, Germany3 Eszterházy Károly College, Eger, Hungary4 Faculdade de Engenharia, Universidade do Porto, Porto, PortugalThe identification of interfacial atoms or molecules is a recurrent problem in many fieldsof chemical physics. In particular, it is of fundamental importance in the investigation of aliquid-vapor or liquid-liquid interface, where the presence of capillary waves requires a detailedknowledge of the surface shape in order to properly characterize its physicochemical properties[1]. In a recent work [2] a comparative analysis showed that the ITIM algorithm [3], basedon a ray-tracing approach, is so far the best compromise between speed and accuracy. Herewe present a generalization of the ITIM algorithm, based on an extension of the concept ofalpha-shapes [4] for the identification of interfacial molecules independently on the shape of theinterface. The features and computational performances of this approach are presented, and examplesof molecular systems with different geometry (planar, spherical and cylindrical) are shown.[1] E. Chacón, P. Tarazona, Phys. Rev. Lett. 91, 166103 (2003)[2] M. Jorge, P. Jedlovszky, M. N. D. S. Cordeiro, J. Phys. Chem. C 114, 1169 (2010)[3] L. B. Partay, G. Hantal, G. , P. Jedlovszky, A. Vincze and G. Horvai, G. J. Comput. Chem. 29,945 (2008)[4] H. Edelsbrunner, E. Mücke, ACM Trans. Graph. 13, 43 (1994)55