Change here the properties of a crystallographic or atomic direction
(or list of directions, previously selected with Direction->Select,
when
Global is pressed).
Parameters for empty entries or
Local choices remain unchanged.
To change the direction name write the new name in the Direction entry, followed
by the direction number (GAMGI only needs the number to identify the direction).
Reference
GAMGI can handle crystallographic directions, related with a cell containing
the relevant crystallographic information, and atomic directions, defined by
two non-coincident atoms.
To create crystallographic directions, set
Reference to
Cell.
GAMGI automatically shows a
Cell entry, plus
u,
v,
w
entries to indicate the direction indices, plus a
Vectors menu, to select
the cell vectors to use,
Conventional or
Primitive. For the sake of
simplicity, GAMGI does not accept 4-indice notation for planes or directions
in hexagonal cells.
Pressing the mouse over a cell in the current layer, the cell identification
is automatically written in the
Cell entry. When a valid cell is found
and its
Type is
Projection, the default
Line page
is automatically replaced by a
Projection page.
By default, only one family of crystallographic directions is created.
To create a set of families simultaneously, press the button
Set (TODO).
When
Reference is set to
Atoms, GAMGI automatically shows
two
Atom entries. Pressing the mouse sucessively over two
non-colinear atoms in the current layer, the two entries become occupied
and the direction defined. After pressing
Ok, an error is shown
if the atoms are coincident.