  A first-principles approach is demonstrated to calculate the relationship
between aqueous semiconductor interface structure and energy level alignment.
The physical interface structure is sampled using density functional theory
based molecular dynamics, yielding the interface electrostatic dipole. The $GW$
approach is used to place the electronic band edge energies of the
semiconductor relative to the occupied $1b_1$ energy level in water.
Application to the specific cases of non-polar $(10\bar{1}0)$ facets of GaN and
ZnO reveals a significant role for the structural motifs at the interface,
including the degree of interface water dissociation and the dynamical
fluctuations in the interface Zn-O and O-H bond orientations. These effects
contribute up to 0.5 eV.
