The XPLOR energy function can be grouped into two different classes:
describes the energy of the molecule(s) through an empirical
energy function described below.
comprises restraining energy terms that use experimental
information or other information:
The 
, 
, 
,
, 
, 
, 
, and 
terms are described in Chapters
12,
18, 7.1, 7.2,
16, 19, 21, and 7.3,
respectively.
