This manuscript introduces the concept of scaling factors for rotational constants. These factors are designed to bring computed equilibrium rotational constants closer to experimentally fitted ground-state-averaged rotational constants. The parameterization of the scaling factors was performed for several levels of theory, namely DF-Dn/def2-mVP ($\mathrm{DF}=\mathrm{B}3\mathrm{LYP},\mathrm{PBE}0$, $n=3\left(\mathrm{BJ}\right),4$, $m=\mathrm{S},\mathrm{TZ}$), PBEh-3c, and r${}^2$SCAN-3c. The obtained scaling factors systematically improved the consistency between the theoretical and experimental rotational constants.

This manuscript introduces the concept of scaling factors for rotational constants. These factors are designed to bring computed equilibrium rotational constants closer to experimentally-fitted ground-state-averaged rotational constants. The parameterization of the scaling factors was performed for several levels of theory, namely DF-Dn/def2-mVP (DF=B3LYP,PBE0, n=3(BJ),4, m=S,TZ), PBEh-3c, and r2SCAN-3c. The obtained scaling factors systematically improve the consistency between theoretical and experimental rotational constants.