Define here the location of the node (0 0 0).
O1, O2, O3
These entries provide the coordinates of the node in the lower-left
corner of the cell where the new origin is, calculated with conventional
or primitive cell vectors. When the lattice is primitive or vectors are
primitive, this corner node becomes the new origin node (0 0 0) and no more
coordinates are needed.
The cell position, given by the coordinates x,y,z of the origin node,
is not affected by a change in the origin node, so the new origin node
must occupy the position kept by the previous origin node, forcing a
cell translation. The new cell origin can be outside the current cell volume.
O4
When the lattice is centered and vectors are conventional,
a fourth coordinate
o4 is needed to point the new origin
node (000) to one of the centered nodes. By default,
o4
is
000, so no change is introduced. When the cell lattice
is primitive
P or the vectors defining the origin are primitive,
that is the only possible value for
o4. For I, C, F, R centered
lattices,
o4 can also take the values:
I: 111
C: 110
F: 110, 101, 011
R: 211, 122
corresponding to the numerators of the inner node coordinates,
(1/2 1/2 1/2) for
I lattices, (1/2 1/2 0) for
C
lattices, (0 1/2 1/2) (1/2 0 1/2) (1/2 1/2 0) for
F
lattices and (1/3 2/3 2/3) (2/3 1/3 1/3) for
R lattices.
Vectors
Indicate the type of cell vectors,
Conventional or
Primitive,
used to determine the node with
o1,
o2,
o3 coordinates,
as described above. When
o4 is not
000, a centered cell is
involved and
Vectors must be
Conventional.
Axes
Controls whether cell axes are visible. Axes are positioned at node
(0 0 0), and can be represented either by conventional or by primitive
vectors. The three axes use the rgb color scheme: red for the first
axis, green for the second and blue for the third.
Vectors
Indicate the type of cell vectors to show,
Conventional
or
Primitive. These are totally independent of the vectors
used to indicate the node (0 0 0).