SRW Crystal

https://en.wikipedia.org/wiki/Monochromator.

See Dynamical-access-of-crystal-data-and-optical-constants-from-external-servers for details about automatic accessing the crystal parameters from http://x-server.gmca.aps.anl.gov/x0h.html.

Here is a demo of SRW automatically obtaining online data from the X0h (chi-zero-h) server maintained by Dr. Sergey Stepanov at Argonne National Laboratory (ANL). Automated access of X0h data server for crystal properties