  The relativistic coupled-cluster (RCC) method is a powerful many-body method,
particularly in the evaluation of electronic wave functions of heavy atoms and
molecules, and can be used to calculate various atomic and molecular
properties. One such atomic property is the enhancement factor (R) of the
atomic electric dipole moment (EDM) due to an electron EDM needed in electron
EDM searches. The EDM of the electron is a sensitive probe of CP-violation, and
its search could provide insights into new physics beyond the Standard Model,
as well as open questions in cosmology. Electron EDM searches using atoms
require the theoretical evaluation of R to provide an upper limit for the
magnitude of the electron EDM. In this work, we calculate R of 210Fr in the
ground state using an improved RCC method, and perform an analysis on the
many-body processes occurring within the system. The RCC method allows one to
capture the effects of both the electromagnetic interaction and P- and
T-violating interactions, and our work develops this method beyond what had
been implemented in the previous works. We also perform calculations of
hyperfine structure constants, electric dipole transition matrix elements, and
excitation energies, to assess the accuracy of R and the success of our
improved method. Finally, we present calculations of R with corrections due to
Breit interaction effects, approximate quantum electrodynamics (QED) effects,
and some leading triple excitation terms added perturbatively, to assess how
significantly these terms contribute to the result. We obtain a final value of
R = 799, with an estimated 3% error, which is about 11% smaller than a
previously reported theoretical calculation.
