An interatomic potential for zirconium diboride. The potential is of the Tersoff form, and is obtained by fitting to a first-principles database of basic properties of elemental Zr, B, and ZrB2 compound. Two variants of the Zr-B potentials have been obtained, this is the second potential described in the paper (pot 2). The potentials have been tested against a variety of properties of the compound, with the conclusion that they are stable and provide a reasonable representation of the desired properties of zirconium diboride.