  The work function is a fundamental electronic property of a solid that varies
with the facets of a crystalline surface. It is a crucial parameter in
spectroscopy as well as materials design, especially for technologies such as
thermionic electron guns and Schottky barriers. In this work, we present the
largest database of calculated work functions for elemental crystals to date.
This database contains the anisotropic work functions of more than 100
polymorphs of about 72 elements and up to a maximum Miller index of two and
three for non-cubic and cubic crystals, respectively. The database has been
rigorously validated against previous experimental and computational data where
available. We also propose a weighted work function based on the Wulff shape
that can be compared to measurements from polycrystalline specimens, and show
that this weighted work function can be modeled empirically using simple atomic
parameters. Furthermore, for the first time, we were able to analyze simple
bond breaking rules for metallic systems beyond a maximum Miller index of one,
allowing for a more generalized investigation of work function anisotropy.
