Dynamic QM/MM: A Hybrid Approach to Simulating Gas–Liquid Interactions - Multiscale Molecular Methods in Applied Chemistry - page 65

to the short time (few ps) and small spatial regions (100-200 quantum atoms)
required for describing the hyperthermal dynamics. Even with this limitation, there
are a growing number of applications accessible to this method, as high energy
atomic sources provide useful information about the structure and reactivity of
liquid surfaces. The same technology can also be used to describe gas-solid
reactions, as reviewed elsewhere [ 27 ], and in this case it is relevant to a number
of important industrial etching processes as well as space materials research.
Thermal reactions at gas-liquid interfaces can also be described, but the computa-
tional effort can easily get out of hand unless one implements additional compo-
nents in the calculations (such as umbrella sampling so that the reacting species are
initiated in close contact). Ultimately one needs to separate the reactive event for
such problems from adsorption and diffusion, and there are serious questions as to
whether a dynamic QM/MM approach is going to be the most useful way to
describe the dynamics.
Acknowledgments This research was supported by AFSOR Grant FA9550-10-1-0205 and by the
CENECI CCI NSF grant CHE-0943639.
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