This package contains the commands needed to calculate x-ray and
electron diffraction intensities based on kinematic diffraction
theory. Detailed discription of the computation can be found in the
following works:

Coleman, S.P., Spearot, D.E., Capolungo, L.  (2013) Virtual
diffraction analysis of Ni [010] symmetric tilt grain boundaries,
Modelling and Simulation in Materials Science and Engineering, 21
055020. doi:10.1088/0965-0393/21/5/055020

Coleman, S.P., Sichani, M.M., Spearot, D.E.  (2014) A computational
algorithm to produce virtual x-ray and electron diffraction patterns
from atomistic simulations, JOM, 66 (3), 408-416.
doi:10.1007/s11837-013-0829-3

Coleman, S.P., Pamidighantam, S. Van Moer, M., Wang, Y., Koesterke, L.
Spearot D.E (2014) Performance improvement and workflow development
of virtual diffraction calculations, XSEDE14,
doi:10.1145/2616498.2616552

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User-diffraction includes:

1) compute_xrd :  calculate x-ray diffraction intensities as a
                  scattering angle (2theta)

2) compute_xrd_consts.h :  coefficients used for x-ray atomic
                           scattering factors listed by element

3) compute saed : calculate 3D diffraction intensities for the
                  purpose of creating selected area electron
                  diffraction patterns

4) compute_xrd_consts.h :  coefficients used for electron atomic
                           scattering factors listed by element

3) fix saed/vtk :  writes 3D diffraction intensity data calculated
                   with "compute saed" in vtk format


See the doc pages for these commands for detailed usage instructions.

There are example scripts for using this package in
examples/PACKAGES/diffraction.

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AUTHOR INFORMATION:

The person who created this package is Shawn P. Coleman
(scolema3 at gmail.com) while at the University of
Arkansas.  Contact him directly if you have questions.

Co-Author:  Douglas Spearot (University of Arkansas)

---------------------------------

Thanks for contributions, support and testing goes to

Sudhakar Pamidighantam (National Center for Supercomputing Applications)
Mark Van Moer  (National Center for Supercomputing Applications)
Yang Wang (Pittsburgh Supercomputing Center)
Lars Koesterke (Texas Advanced Computing Center)
Eric Homer (Brigham Young University)

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VERSION: 2016-07-15
