Link to NIST Center for Neutron Research home page Link to National Institute of Standards & Technology home page
Link to Tcl/Tk information

EXPGUI

EXPGUI top

A.7 Preferential Orientation Pane

The Preferential Orientation Pane is used to control parameters related to fitting parameters using the March-Dollase formulation for preferred orientation. In this model one or more axes are designated as directions [designated by (hkl)] where crystallites are over (Ratio > 1) or underrepresented (Ratio < 1). The checkbox to the right of the Ratio value determines if it will be refined.
If more than one axis is present, one must define the relative fraction of preferred orientation for each direction. These fractions are normalized, so do not vary the fractions for all directions in a phase.
If "Multiple Histogram Selection" mode is set to any value other than "Off", all terms are displayed for all selected histograms. No attempt is made to group terms or flags.

Note that the other model for treating preferred orientation -- the orientation distribution function (spherical harmonics) is not yet implemented in EXPGUI and must be accessed from EXPEDT.


EXPGUI top

Brian Toby (Brian.Toby@NIST.GOV)
$Revision: 224 $ $Date: 2009-12-04 23:02:28 +0000 (Fri, 04 Dec 2009) $