Bimolecular rates are at the moment only implemented for one atom reacting with a molecule. qts_reactant.txt refers to the reactant molecule. I.e. it has 3 degrees of freedom less than the classical TS. qts_reactant.txt has to be adapted manually: the energy of the incoming atom has to be added to the third line (which contains the energy of the reactant molecule). Additionally, the mass on the incoming atom (in atomic mass units) should be appended at the third line (thus, two real values in the third line).
The relative partition function of the incoming atom will be calculated and replaces the vibrational partition function for three degrees of freedom. The rate is internally calculated in atomic units (as is the case for uni-molecular reactions), but will be converted to molecules cm s upon output.