Pair distribution function (PDF) methods have great potential for the study of diverse high‐pressure phenomena. However, the measurement of high‐quality, high‐resolution X‐ray PDF data (to Qmax > 20 Å−1) remains a technical challenge. An optimized approach to measuring high‐pressure total scattering data for samples contained within a diamond anvil cell (DAC) is presented here. This method takes into account the coupled influences of instrument parameters (photon energy, detector type and positioning, beam size/shape, focusing), pressure‐cell parameters (target pressure range, DAC type, diamonds, pressure‐transmitting media, backing plates, pressure calibration) and data reduction on the resulting PDF. The efficacy of our approach is demonstrated by the high‐quality, high‐pressure PDFs obtained for representative materials spanning strongly and weakly scattering systems, and crystalline and amorphous samples. These are the highest‐resolution high‐pressure PDFs reported to date and include those for α‐alumina (to Qmax  =  20 Å−1), BaTiO3 (to Qmax = 30 Å−1) and pressure‐amorphized zeolite (to Qmax  =  20 Å−1).

The pressure induced amorphization of the negative thermal expansion material cubic ZrMo2O8 was examined in situ within a diamond anvil cell, using high energy x-ray total scattering, during compression up to ∼7.2 GPa, and then decompressed. The amorphization upon compression was largely complete by ∼3 GPa. There was significant, but not complete, structural relaxation of the amorphous material on decompression; the pair distribution function (PDF) for the material recovered from 7.2 GPa closely resembled that for the sample during initial compression at ∼5.5 GPa. The PDFs indicated that the amorphization, densification, and relaxation of the amorphous solid involve changes in the first coordination shell of molybdenum and the creation/loss of Mo-O-M bridges with ∼3.4 Å Mo-M separation (M–Mo or Zr).