  Highly correlated pure {\it{ab initio}} relativistic configuration
interaction theory is in the present paper applied to the calculation of the
tensor-pseudotensor ${\cal{(P,T)}}$-violating nucleon-electron interaction
constant in the electronic ground states of atomic mercury and radium. The
final best obtained results are $R_T$(Hg) = $-4.43$\, [$10^{-20}$
$\left<\sigma_N\right>$ $e$ cm] and $R_T$(Ra) = $-15.0$\, [$10^{-20}$
$\left<\sigma_N\right>$ $e$ cm]. The accuracy of the employed
electronic-structure models are confirmed by determining the static electric
dipole polarizability $\alpha_d$(Hg) = $35.7$ {\it{a.u.}} which is in accord
with the experimental value to about $5$\%. $R_T$(Ra) will be useful for
constraining (or obtaining) the ${\cal{(CP)}}$-violating parameter $C_T$ when
combined with future measurements of the electric dipole moment of the radium
atom.
