Using artificial neural networks, researchers in Bochum and Vienna have examined the atomic interactions of water molecules. Based on their findings, they explain the melting temperature of ice and the density maximum at four degrees Celsius – based solely on computer simulations. The newly developed method is just as precise as quantum mechanical calculations, but is 100,000 times faster. The teams of PD Dr. Jörg Behler of the Ruhr-Universität Bochum and Prof. Dr. Christoph Dellago of the University of Vienna describe the work in the journal “Proceedings of the National Academy of Sciences” or PNAS.