  A generally applicable approach for the calculation of relativistic
one-electron properties with two-component wave functions is presented. The
formalism is explicitly evaluated for the example of quasi-relativistic
wavefunctions obtained within the zeroth order regular approximation (ZORA).
The wide applicability of the scheme is demonstrated for the calculation of
parity ($\mathcal{P}$) and time-reversal ($\mathcal{T}$) symmetry violating
properties, which are important for searches of physics beyond the standard
model of particle physics. The quality of the ZORA results is shown exemplarily
for the molecules RaF and TlF by comparison to data from four-component
calculations as far as available. Finally, the applicability of RaF in
experiments that search for $\mathcal{P,T}$-violation not only in the
electronic but also in quark sector is demonstrated.
