Due to the undercoordination of a small fraction of the Zn 2+ nodes in the glasses, a small deviation is expected, and observed for the ab initio glass, with a wider distribution and tail at higher angle values. However, the ReaxFF glass distribution is very different, with a broad distribution of angles on the 70-170 • spectrum. This distribution is unphysical, and does not reproduce the known tetrahedral chemistry of the system, suggesting ill-adjusted angle constraints in the force field. The angular PMF shown on Figure further evidences the tendency of this force field to have the ReaxFF glass deform too easily.