Enhancement factor for the electron electric dipole moment in francium   and gold atoms
  If electrons had an electric dipole moment (EDM) they would induce EDMs of atoms. The ratio of the atomic EDM to the electron EDM for a particular atom is called the enhancement factor, R. We calculate the enhancement factor for the francium and gold atoms, with the results 910 plus/minus 5% for Fr and 260 plus/minus 15% for Au. The large values of these enhancement factors make these atoms attractive for electron EDM measurements, and hence the search for time-reversal invariance violation. 
T.M.R. Byrnes, V.A. Dzuba, V.V. Flambaum, D.W. Murray (University of   New South Wales)