Jcpds Xrd ((link)) Jun 2026

Leo ran his finger over the card. “So before computers… people did this by hand?”

“By eye,” Elara corrected. “You’d take your unknown sample’s pattern, pick your three strongest peaks, and flip through the ‘Hanawalt Search Manual’—a book of numbers—until you found a candidate. Then you’d check the rest of the peaks. It could take days. A PhD student’s entire thesis could be derailed by a single mismatched peak at 2θ = 28.4°.” jcpds xrd

A typical entry in the JCPDS database, often displayed as a "card" in software, is a wealth of information. The most critical data for analysis includes the $d$-spacings and the corresponding relative intensities, which are used to match the experimental peaks. However, a JCPDS entry is more than just a list of numbers. Leo ran his finger over the card

And the library of dust grew by one more peak. Then you’d check the rest of the peaks