Work Functions for Photoelectric Effect
Some data from Handbook of Chemistry and Physics.
* The case of silver apppears to be somewhat unique in that the work functions measured for different crystal faces are significantly different. For polycrystalline silver a value of 4.26 eV has been measured, but for a single crystal a value of 4.74 eV has been measured for the (111) face, with intermediate values of 4.64 eV (100) and 4.52 eV (110). Dweydari, A. W.; Mee, C. H. B. (1975). "Work function measurements on (100) and (110) surfaces of silver". Physica Status Solidi (a) 27: 223.
Tipler & Llewellyn