: An online version of the PDF-4+ database is available via browser, though it still requires an active, paid user registration. 🟡 Reliable Free Alternatives
If you cannot get access to the ICDD database, there are legitimate, free, open-source databases you can use for XRD analysis. These are excellent alternatives for standard phase identification. Icdd Pdf-4 Database Free Download
If you genuinely cannot afford PDF-4 and have no institutional access, these free/open-source alternatives can handle 80% of basic phase identification needs. : An online version of the PDF-4+ database
If you need powder diffraction data without paying, use these: | Resource | Content | Link | |----------|---------|------| | | >500k entries, many with calculated powder patterns | crystallography.net | | American Mineralogist Crystal Structure Database | Mineral powder patterns | rruff.info/ima | | RRUFF Project | Raman + XRD of minerals, free spectra | rruff.info | If you genuinely cannot afford PDF-4 and have