The properties of several hybrid mass relations are examined through the study of (i) statistical tests, (ii) systematic effects, and (iii) the structure of the solutions of partial difference equations. The usefulness of the relations is discussed. Mass relations based on the effective neutron-proton interaction and on derivatives thereof have particularly small relation inaccuracies.

• Received 10 July 1985

DOI:https://doi.org/10.1103/PhysRevC.32.1390