3.5.24 - GEOM atom-name
Interactive calculation of geometry around atom, i.e bond distances and bond angles.
3.5.25 - HELP
(ALL/BOX/BWC/COLOUR/DATA/GEOMETRY/GRAPHICS/INCLUDE/JOIN/
LABEL/LIMITS/LIST/MOLES/PLOT/RADII/SEGMENT/SIZE/ STYLE/SPGR/VIEW)
This gives on-line help on the specified type of instructions. In particular HELP GRAPHICS
will inform on the way the graphics is implemented. HELP SPGR gives a listing of all the
space group names known to the program. HELP ALL gives the full list of available
instructions.
Example:
HELP STYLE
3.5.26 - INCLUDE atom-names/atom-types/ALL/NONE/ORIG/*/&
Include the specified atoms in the atom list. See EXCLUDE.
3.5.27 - INORG
I
nstruction modifies defaults to suitable values for inorganic compounds.
3.5.28 - JOIN (RADII (UNIQUE (EXPAND)) (NOMOVE) (TOLE tole[0.7]) (TOL tol[0.2])/
(atom-type1 r1 atom-type2 r2 ...))
A PLOT instruction that, since the start of the program or after a RESET, was not preceded
by any JOIN instruction will automatically invoke the execution of a JOIN RADII UNIQUE
EXPAND instruction. This automatically produces a list of connections, an ARU-list and an
atom list for the possibly symmetrical molecule(s) in the structure, based on internal
covalent atomic radii. All distances between two, possibly symmetry transformed, atoms
less than the sum of the covalent radii for the two atoms plus a tolerance (by default tol =
0.2 Angstrom per atom) will be entered in the connection list and related changes or
additions are made to the molecule and atom lists. Atoms are moved (unless NOMOVE
disables it to do so) to symmetry-equivalent positions in order to form connected fragments.
If the molecule has symmetry coincident with space group symmetry operators and only the
asymmetric coordinate set supplied, the program will look for connections between the
symmetry-related portions of the molecule. This involves the generation of dummy atoms
and modification of the molecule list as well so that the PLOT instruction will show the
complete molecule. The radii used for the automatic JOIN instruction can be inspected with
the LIST TYPES instruction. The user may override this automatic feature by explicitly
specifying the required JOIN instruction(s) before the first PLOT instruction. When the
EXPAND sub-keyword is left out the molecules will not be fully symmetry expanded as is
needed for molecules exceeding threefold site symmetry. Symmetry is not taken into
account when in addition to this the UNIQUE sub-keyword is left out so that the user is held
responsible to provide the correct set of atomic coordinates assumed to be already in
bonding distance. Also the atomic radii used may be changed by their explicit specification:
JOIN RADII C 0.85 BR 1.35 H 0.4