Water is both an extremely common and an extremely unusual liquid, with anomalous properties such as high surface tension, high viscosity, and temperature of maximum density. Although these macroscopic properties can be well characterized experimentally, resolving the atomistic picture remains challenging. In fact, even the structure of the water is still subject to intense debate. It is also important to understand how water behaves as a solvent or reactant, whether in the bulk or near an interface as these properties are of central importance in many fields, such as from atmospheric science, photochemistry, and biochemistry. Hence, water has received great attention in both experimental and theoretical studies across diverse scientific disciplines.