the identification of antibiotic drugs such as: eight β-lactam (ampicillin sodium, penicillin G procaine, cefalexin, ampicillin trihydrate, benzathine penicillin, benzylpenicillin sodium, cefotaxime sodium, Ceftriaxone sodium), three tetracycline (doxycycline hydrochloride, oxytetracycline dehydrate, tetracycline hydrochloride) and two macrolide (azithromycin, erythromycin estolate) antibiotic drugs. Each of these drugs has a unique X-Ray Diffraction (XRD) pattern that makes their identification possible. Characterization of nanomaterials, textile fibers and polymers Forensic examination of any trace evidence is based upon Locard's exchange principle. This states that "every contact leaves a trace". In practice, even though a transfer of material has taken place, it may be impossible to detect, because the amount transferred is very small. XRD has proven its role in the advancement of nanomaterial research. It is one of the primary characterization tools and provides information about the structural properties of various nanomaterials in both powder and thin-film form. Textile fibers are a mixture of crystalline and amorphous substances. Therefore, the measurement of the degree of crystalline gives useful data in the characterization of fibers using X-ray diffractometry. It has been reported that X-ray diffraction was used to identify of a "crystalline" deposit which was found on a chair. The deposit was found to be amorphous, but the diffraction pattern present matched that of polymethylmethacrylate. Pyrolysis mass spectrometry later identified the deposit as polymethylcyanoacrylaon of Boin crystal parameters. Integrated circuits X-ray diffraction has been demonstrated as a method for investigating the complex structure of integrated circuits. See also Beevers–Lipson strip Bragg diffraction Crystallographic database Crystallographic point groups Difference density map Electron diffraction Energy Dispersive X-Ray Diffraction Flack parameter Henderson limit International Year of Crystallography John Desmond Bernal Multipole density formalism Neutron diffraction Powder diffraction Ptychography Scherrer equation Small angle X-ray scattering (SAXS) Structure determination Ultrafast x-ray Wide angle X-ray scattering (WAXS) References Further reading International Tables for Crystallography Bound collections of articles Textbooks , PDF copy of select chapters Applied computational data analysis Historical External links Tutorials Learning Crystallography Simple, non technical introduction The Crystallography Collection, video series from the Royal Institution "Small Molecule Crystalization" (PDF) at Illinois Institute of Technology website International Union of Crystallography Crystallography 101 Interactive structure factor tutorial, demonstrating properties of the diffraction pattern of a 2D crystal. Picturebook of Fourier Transforms, illustrating the relationship between crystal and diffraction pattern in 2D. Lecture notes on X-ray crystallography and structure determination Online lecture on Modern X-ray Scattering Methods for Nanoscale Materials Analysis by