Contents

07 March 2014
Vol 343, Issue 6175

About The Cover

Cover image expansion

COVER Precession image reconstructed from x-ray diffraction data collected from a benzene single crystal. For the past 100 years, x-ray crystallography has been a key tool for determining the structures of ever more complex chemical and biochemical systems. See the special section beginning on page 1091 and at www.sciencemag.org/special/crystallography. Image: Judith A. K. Howard and Michael R. Probert