Ab initio simulations of materials and molecular systems Eric Schwegler, LLNL image is from an ab initio molecular dynamics simulation of sodium chloride solvated in a carbon nanotube

Advances in both experimental techniques and theoretical methods have resulted in the discovery of a wide range of fascinating new properties of materials. However, in many instances, experimental measurements and simple models are insufficient for a complete understanding of the emerging new phenomena at a microscopic level. In such cases, the combination of ab initio simulation methods with large-scale computations have proven to be extremely useful for resolving experimental ambiguities and for predicting the properties of materials where measurements do not yet exist. Broadly speaking, ab initio methods are those based on finding numerical solutions to the fundamental laws of quantum mechanics in an approximate, yet non-empirical manner. These methods have a distinct advantage over semiempirical or classical simulation approaches in that they can provide a quantitatively accurate description of chemically active species in realistic environment. In this talk, I will discuss two recent examples where large-scale ab initio simulations proved to be particularly useful, including unraveling the ground state structure of boron and in understanding the properties of confined water.