| This thesis applies statistical physics approaches and computer simulations to investigate quantitatively the relationship between the structure and the dynamic and thermodynamic anomalies observed in water and some other simple liquids.;In Chapter 1, we give a general introduction to the properties of water. In Chapter 2 we address the question of whether spherically-symmetric potentials are also able to reproduce the structural anomalies found in systems with local tetrahedral order. We find that water-like structural order anomalies exist for the two-scale "ramp potential". Our findings suggest that the water-like relationship between structural order and anomalies is related to the presence of two different length scales in the potential.;In Chapter 3, we use the ratio of characteristic length scales of the two-scale ramp potential as a control parameter to investigate the evolution of dynamic, thermodynamic and structural anomalies. In this manner we show that the family of tunable spherically-symmetric potentials so generated evolves continuously between water-like and hard sphere behavior. These findings suggest that strong orientational interactions in the first shell of water are not necessary for a liquid to show thermodynamic, dynamic and structural anomalies, and highlight the importance of the second shell of water.;In Chapter 4, we investigate how much orientation-dependent first-shell interaction and the second-shell environment each contribute to water's anomalies. We show that the changes in the second shell of water are the structural bases for the anomalies. In Chapter 5, we study the quantitative connection between our idealized ramp potential and water's pair potential, as well as the relation between the regions of anomalies in their respective phase diagrams. Finally in Chapter 6 we show that the "two-body excess entropy" is a useful quantity for predicting the regions of thermodynamic, dynamic and structural anomalies of water. |
