Search

Introduction Underground storage tanks (USTs) and associated piping can be sources of subsurface contamination. The Environmental Protection Agency (EPA) estimates there are 1.75 million UST systems in the United States. [...]

We present an ab initio molecular dynamics simulation of the aqueous liquid-vapor interface. Having successfully stabilized a region of bulk water in the center of a water slab, we were able to reproduce and further quantify the experimentally observed abundance of surface 'acceptor-only' (19%) and 'single-donor' (66%) moieties as well as substantial surface relaxation approaching the liquid-vapor interface. Examination of the orientational dynamics points to a faster relaxation in the interfacial region. Furthermore, the average value of the dipole decreases and the average value of the highest occupied molecular orbital for each water molecule increases approaching the liquid-vapor interface. Our results support the idea that the surface contains, on average, far more reactive states than the bulk., Although the nature of bulk liquid water itself remains incompletely understood, there is a more pressing need to characterize water in more complex environments. In particular, the interfaces between liquid [...]