This potential requires a orientational axis centered on the paramagnetic metal. This consists of a center atom (superimposed on the metal atom) and three other atoms (X, Y, and Z) bonded to the center atom. The axis must have parameters, a molecular structure, and coordinates.

Of course, the molecular structure of the protein must also be defined. Atom selections are fragile, when reading in molecular structures.

Xplor-NIH 2023-11-10