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/USER/diffraction.

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AUTHOR INFORMATION:

The person who created this package is Shawn P. Coleman 
(shawn.p.coleman8.ctr at mail.mil) 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
