Electron- and photon-molecule data for hydrogen plasmas

Studies of low-temperature plasmas both in local thermodynamic equilibrium (LTE) and non-LTE require state-resolved (electronic, vibrational and rotationally resolved) transition cross sections or rate coefficients of molecules to calculate populations (for non-LTE plasmas), opacities and emissivities. Recently we developed ab initio methods and general codes to calculate electron- and photon-molecule collision data of hydrogen H2 [1,2], the ion H2$+$ [3,4] and the isotopologues. We highlight results that differ with commonly ``accepted'' and used data, which may have implications in astrophysics and fusion plasma modeling. For example, we note that for material temperatures T\textless 2000 K, isotopic effects should be take into account to obtain LTE-averaged photodissociation cross sections accurate to better than 10-20{\%}. [1] M. C. Zammit et al. Phys. Rev. Lett. 116, 233201 (2016) [2] M. C. Zammit et al. Phys. Rev. A 95, 022708 (2017) [3] M. C. Zammit et al. Phys. Rev. A 90, 022711 (2014) [4] M. C. Zammit et al. Astrophys. J. 851, 64 (2017)