Characterization of heteropoly acids by X-ray powder diffraction at SPring-8

X-Ray Powder Diffraction Metrics

To compare sample data from x-ray diffraction a suitable metric is developed to evaluate the similarity (or dissimilarity) between samples and to compare it to a references. The methodology focuses on the d-lines and uses the intensity measurements indirectly in the algorithm. The resulting d-line distribution and summary statistics of the differences is used to establish whether a true differe...

Two-dimensional X-ray powder diffraction

X-ray powder diffraction on proteins

Macromolecular structures are traditionally determined by means of single crystal X ray diffraction from protein crystals of micrometer dimensions. Nevertheless, the growth of good quality single crystals can be very difficult or even impossible, especially in cases of large proteins, membrane proteins or protein complexes. Modern developments of X-ray powder diffraction have allowed the struct...

Acemetacin cocrystal structures by powder X-ray diffraction

Cocrystals of acemetacin drug (ACM) with nicotinamide (NAM), p-aminobenzoic acid (PABA), valerolactam (VLM) and 2-pyridone (2HP) were prepared by melt crystallization and their X-ray crystal structures determined by high-resolution powder X-ray diffraction. The powerful technique of structure determination from powder data (SDPD) provided details of molecular packing and hydrogen bonding in pha...

Clarithromycin form I determined by synchrotron X-ray powder diffraction.

The structure of the metastable form I polymorph of the macrolide antibiotic clarithromycin, C(38)H(69)NO(13), was determined by a powder diffraction method using synchrotron radiation. The space group of form I is P2(1)2(1)2. The initial model was determined by a molecular replacement method using the structure of clarithromycin form 0 as a search model, and the final structure was obtained th...