Links

Materials Project (https://materialsproject.org/#)
Inorganic Crystal Structure Database (ICSD)
ASM alloy phase diagram database
The open quantum materials database (OQMD)
Topological Materials Database (https://www.topologicalquantumchemistry.com/#/)
Neutron scattering lengths and cross sections (https://www.ncnr.nist.gov/resources/n-lengths/)
X-ray mass attenuation coefficients (https://physics.nist.gov/PhysRefData/XrayMassCoef/tab3.html)