Definitions for

**"Stationary point"**the position at which the rate of change of the apparent right ascension (see apparent place) of a planet is momentarily zero.

A geometry at which the first derivatives of the energy with respect to atomic coordinates are all zero. Note that this could correspond to either a minimum or a maximum.

The point where an outer planet changes between direct motion and retrograde motion.

a global minimizer of f

a point that doesn't move at all