Charles W. Clark, aka Carbon Tungsten Chlorine Argon Potassium, is among a select group of NIST staff whose surnames can be spelled with the chemical symbols of consecutive elements of the Periodic Table. In addition to this distinction, Charles is a NIST Fellow and Fellow and past co-director of the Joint Quantum Institute (JQI), a research collaboration that includes NIST and the University of Maryland. His research activities are focused on theoretical atomic, molecular and optical physics.