  The mode specific dissociative chemisorption dynamics of ammonia on the
Ru(0001) surface is investigated using a quasi-classical trajectory (QCT)
method on a new global potential energy surface (PES) with twelve dimensions.
The PES is constructed by fitting 92524 density functional theory points using
the permutation invariant polynomial-neural network method, which rigorously
enforces the permutation symmetry of the three hydrogen atoms as well as the
surface periodicity. The PES enables highly efficient QCT simulations as well
as future quantum dynamical studies of the scattering/dissociation dynamics.
The QCT calculations yield satisfactory agreement with experiment and suggest
strong mode specificity, in general agreement with the predictions of the
Sudden Vector Projection model.
