Alladi Ramakrishnan Hall

Hierarchical Models of Hydrogen Bond Networks in Water

Rahul Dandekar

ICTP, Trieste

Abstract: We develop models of the Hydrogen Bond network of water that are
built *bottom up*, based on microscopic information coming from atomistic
simulations. These models are essentially graph-based models for the
hydrogen bond network of water. The phase diagram of these models confirms
the singularity-free scenario previously proposed by Sastry and co-workers
(Sastry et al, PRE 53, 6144 (1996)). We examine the pair-distribution
functions on the lattice, orientational correlations, and loop statistics
in our model network and find substantial agreement with ab-initio
simulations. Our models reproduce some important anomalies such as the
density maximum and compressibility minimum the exact details of which, are
sensitive to the presence of coordination defects in the network.