Ball-and-stick figure of AZM and zinc (magenta sphere) in the HCA II active site. Heavier sulfur atoms (red) are clearly visible in the electron density map (blue; contoured at 2.0 s), while light deuterium atoms (cyan) are visible in the nuclear density map (yellow; contoured at 1.5 s).
Credit or Source: Los Alamos National Laboratory
US DOE. 2013. DOE User Facilities Advanced Technologies for Biology: Synchrotron and Neutron Beam Facilities Accelerating Biological Research, US Department of Energy Office of Science. (p. 4)