Towards detection of molecular parity violation by microwave spectroscopy of CpRe(CH${}_3$)(CO)(NO)

Parity-violating differences in rotational constants of a chiral 5d transition metal complex, that was previously experimentally well-characterised by broad-band microwave spectroscopy, are predicted with a recently established efficient analytical derivative technique. Relative differences $\mathrm{\Delta }X\mathrm{/}X$ between rotational constants $X=A,B,C$ of enantiomers of the title compound are found to be on the order of ${10}^{-14}$, which is a favourably large effect. The quality of the theoretical estimates is carefully assessed by computing nuclear electric quadrupole coupling constants that agree well with experiment.