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The structures and properties of biomolecules like proteins, nucleic acids, and membranes depend on water. Water is also very important in industry. Overall, water is an unusual substance with more than 70 anomalous properties. The understanding of water is advancing significantly due to the theoretical and computational modeling. There are different kinds of models, models with fine-scale properties and increasing structural detail with increasing computational expense, and simple models, which focus on global properties of water like thermodynamics, phase diagram and are less computationally expensive. Simplified models give a better understanding of water in ways that complement more complex models. Here, we review analytical modelling of properties of water on different levels, the two- and three-dimensional Mercedes– Benz (MB) models of water and experimental water.

Understanding the spatial folding of proteins from their amino acid sequences has an enormous potential in contemporary life sciences. The ability to predict secondary and tertiary structures from the primary through the use of computers will enable a much faster and more efficient discovery of organic substances with therapeutic or otherwise bioactive potential, largely eliminating the need for synthesis and testing of large numbers of organic substances for physiological effects. Our manuscript presents an application of correlation function analysis, usually used to describe properties of liquids, to protein structures in order to elucidate statistically favored distances among amino acids. Pairwise distribution functions were calculated between C-alpha atoms of 20 amino acids in a large ensemble of Protein Data Bank structures. The correlation functions show characteristic distances in amino acid interactions.

Methanol and water rank among the most important liquids in modern world due to their versatile use. As water, methanol and their mixture exhibit numerous anomalous properties, their description is challenging. Amphiphilic nature of methanol causes its aqueous solutions to have negative excess volume and enthalpy across entire composition range. Simple isotropic water model and its coarse-grained extension were used to study properties of methanol and water-methanol mixtures. Using Monte Carlo simulations, we showed that the model correctly describes the thermodynamic properties of methanol, ordering of water and methanol in mixtures, density dependence upon temperature and composition, and excess properties of mixtures. Although no conscious effort was made to fine-tune the potential, the results are remarkably close to experimental data.