OOF2: The Manual
Name
Bunge (Bunge) — Bunge angles for defining a rotation which operates on the lab axes, bringing them into coincidence with the crystal axes, in the order z, x, z.
Synopsis
Bunge
(phi1
,theta
,phi2
)
Details
-
Base class:
Orientation
-
Parameters:
phi1
- First rotation, about z axis, in degrees. Type: A real number in the range [-180, 180].
theta
- Second rotation, about x axis, in degrees. Type: A real number in the range [0, 180].
phi2
- Third rotation, about z axis, in degrees. Type: A real number in the range [-180, 180].
Description
A Bunge
object represents the orientation
of a three dimensional object, assumed to be a crystal, in three
dimensional space in terms of three angles,
,
,
and
,
corresponding to rotations which
bring the lab (or screen) axes
,
, and
into
coincidence with the crystalline
,
, and
, axes,
respectively. This is the conventional usage of the texture
community, and is the opposite of the usual
sense for rotations in OOF2.
With this important difference, it resembles the X convention, in that the axis
selection and ordering are the same. The
rotation is about the initial
laboratory axis
, the second
rotation is about the rotated laboratory
axis, and the
third
rotation is about the rotated
axis.
The OOF2 implementation of this method actually constructs the
usual OOF2 rotation matrix (which takes the crystalline axes
into the laboratory axes), but does so from the conventionally
specified Bunge parameters. Users familiar with the
Bunge
convention can thus use previously
obtained or instrument provided angles directly.