Testing Protocols for Obtaining Reliable Pair Distribution Functions from Laboratory X-Ray Sources Using PDFgetX3

Herein, data acquisition protocols are explored and data reduction protocols are improved using PDFgetX3 to obtain reliable data for atomic pair distribution function (PDF) analysis from a laboratory-based Mo K_α X-ray source. A variable counting scheme is described that preferentially counts in the high-angle region of the diffraction pattern. The effects on the resulting PDF are studied by varying the overall count time, the use of Soller slits, and limiting the out-of-plane divergence of the incident beam. The protocols are tested using an amorphous silica and a quartz sample. A Python script is presented that allows the comparison of PDFs obtained from different instruments and different acquisition protocols and does automatic uncertainty estimation and error propagation. A modification to the current PDFgetX3 data corrections to take care of sample absorption is also presented, which was previously neglected in the use of that program for high-energy synchrotron X-ray data.