Software for computations of rovibrational states' energies and corresponding spectroscopic constants in diatomic molecules

I need to compute rovibrational energy levels and also the spectroscopic constants, especially $\omega\_e$ to compare my results with other papers. 


So far I've tried [LEVEL16](http://scienide2.uwaterloo.ca/%7Erleroy/LEVEL16/), which seems very promising, but, unfortunately, it seems, that it provides just some of the constants, as described in [How to obtain spectroscopic constants Omega\_e, Alpha\_e, B\_e, D\_e and D\_0 from centrifugal constants?](https://chemistry.stackexchange.com/questions/113028/how-to-obtain-spectroscopic-constants-omega-e-alpha-e-b-e-d-e-and-d-0-from-ce).


Also I've tried [Psi4](http://www.psicode.org/) and [Molcas Vibrot](http://molcas.org/documentation/manual/node115.html), but none of them is able to fit my potential energy curves precisely enough and contrary to LEVEL16 they don't provide parameters to modify interpolation behavior.


Finally I've tried [Duo](https://github.com/Trovemaster/Duo), but I found out, that it isn't able to compute rovibrational energy levels and constants from point-wise computed function as described in [this issue](https://github.com/Trovemaster/Duo/issues/2#issuecomment-487010268).


**Do you know any other software, which could be used to compute both the rovibrational energy levels AND the spectroscopic constants including $\omega\_e, \alpha\_e, B\_e, D\_e$ and $D\_0$?**


