What can X-ray Crystallography tell us?
X-ray crystal data can give a variety of information. Based on X-ray data the order in which the atoms are attached can be determined, including bond angles and bond lengths. From bond lengths, atomic radii and periodic trends can be inferred. Additionally, the arrangement of the atoms and their orientation in 3D space can sometimes give a researcher an idea of the chemical mechanism for forming that molecule. X-ray Crystallography and DNA. In 1953, two young scientists, James Watson and Francis Crick, proposed the double helical structure of DNA. These conclusions were based on X-ray crystallographic results provided by Rosalind Franklin and base composition studies from Erwin Chargaff. Earlier attempts to solve the structure of DNA using X-ray crystallography were conducted by William Astbury in 1938, but to limited success. The DNA samples were found to be not pure enough. However, Astbury was able to predict that the bases were stacked like a roll of pennies, separated by a distanc
