Theoretical aids in screening candidates for atomic clocks: Illustration for Yb II Rajat K. Chaudhuri, Karl F. Freed, Sudip Chattopadhyay and Uttam Sinha Mahapatra EPL, 98 2 (2012) 23002 Published online: 30 April 2012 DOI: 10.1209/0295-5075/98/23002