Some resources and tools we love…
Materials Science
The Materials Project, computational structure and properties database: Link
Mineral Chemistry Database (incl. Raman, X-ray diffraction): Link
Crystal Structure Resources
Inorganic Crystal Structure Database, ICSD: Link
Crystallography Open Database: Link
American Mineralogist Crystal Structure Database: Link
Crystallography / Symmetry
Bilbao Crystallographic Server: Link
Tutorial introduction to point groups and symmetry: Link
ISOTROPY Structure Suite, software for group theory methods: Link
The space groups in real materials: Link
Scattering Properties
APS X-ray absorption calculator: Link
NIST X-ray transition energy database: Link
NIST neutron scattering lengths and cross sections: Link
NIST neutron activation calculator: Link
Structure Refinement Software
Diffpy-CMI: Link
DISCUS Suite, defect and nano structure simulation and refinement: Link
GSAS-II, Rietveld refinement and more: Link
PDFgui, small- box local structure refinement: Link
RMCProfile, large-box complex modeling: Link
Topas Academic: Rietveld and PDF refinement: Link