An official website of the United States government
Here’s how you know
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
Secure .gov websites use HTTPS
A lock (
)or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.
is invoked from the main level of X-PLOR.
Note: certain
energy terms that are initially off will be turned on
automatically when statements related to
this energy are invoked, but this is generally not the case.
flag-statement:==
EXCLude {*energy-term* }
excludes specified energy-terms.
INCLude {*energy-term* }
includes specified energy-terms.
energy-term:==
ANGL
specifies bond angle energy (default: on).
BOND
specifies covalent bond energy (default: on).
CDIH
specifies dihedral angle restraints energy
(default: off).
DG
is a distance geometry restraint
term (see Chapter 37) (default: off).
DIHE
specifies dihedral angle energy (default: on).
ELEC
specifies intramolecular electrostatic energy (default: on).
HARM
specifies a harmonic energy that
restrains the positions of the molecule (default: off).
HBON
specifies explicit hydrogen-bond energy (default: off).
IMPR
specifies improper dihedral angle (e.g., chirality and planarity) energy
(default: on).
NCS
specifies non-crystallographic positional restraint energy (default:
off).
NOE
specifies distance restraints (see Chapter 20)
(default: off).
PELE
specifies symmetry-related electrostatic energy (default: off).
PLAN
specifies planarity restraints energy (default: off).
PVDW
specifies symmetry-related van der Waals energy (default: off).
RELA
is a complete matrix relaxation effective energy
term (see Chapter 39) (default: off).
VDW
specifies intramolecular van der Waals energy (default: on).
XREF
specifies crystallographic effective energy (default: off).