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

P8.14Thu 811:10-14:00Freezing of water: local structure detection using neuralnetworksPhilipp Geiger 1 and Christoph Dellago 11 University of Vienna, Boltzmanngasse 5, 1090, Vienna, AustriaDistinguishing between different local structures is a complex computational problem ofparamount importance for substances with rich phase diagrams. For instance, the study ofcrystallization of a supercooled liquid requires the detection of particles that are part of thegrowing crystal based only on local environment information [1, 2]. Inspired by the use offeed forward neural networks to determine configurational energies [3], we use such networksin order to determine the structure around individual particles. Our novel method is simple,efficient and does not require the definition of a reference frame. This approach provides an orderparameter for systems exhibiting complex crystal structures, such as high pressure ice phases,where conventional methods of classifying the system symmetry fail.[1] W. Lechner, C. Dellago, J. Chem. Phys. 129, 114707 (2008)[2] W. Lechner, C. Dellago, P. G. Bolhuis, Phys. Rev. Lett. 106, 085701 (2011)[3] J. Behler, M. Parrinello, Phys. Rev. Lett. 98, 146401 (2007)14