Regarding the conditions given by Phil Lightfoot --
The crystal class is really orthorhombic (only pseudo-tetragonal) so one
should not expect the [h 0 l] and [0 k l] classes of reflections to
exhibit the same degree of anisotropic broadening.
Question: Has the powder pattern been acquired of a similar material
where anisotropic broadening is not observed? If so, can you say the
RELATIVE PEAK AREAS of the broadened and non-broadened patterns are the
same? If the same, then the structures are the same. If they are
different, then you might expect a condition of "less than
3-dimensional" ordering (compared to the powder pattern calculated from
a single crystal).
For the condition of "less than 3-dimensionality", is there a way to
model an entire MOSAIC - rather than treat it "normally" as a collection
of very small single crystals (which a mosaic, by definition, is not)?
With regard to modelling the "peak shape", I submit that anisotropic
broadening is a problem of determining the correct "relative peak
breadths" of all the peaks in the pattern. Comments???
[[ Please excuse the overabundance of quotes (" ") for emphasis. ]]
Regards from St. Louis,
Frank May
Department of Chemistry
University of Missouri-St. Louis
St. Louis, MO 63121
TEL: (314) 516-5098
[EMAIL PROTECTED]
