Quantum mechanical calculations of the thermalization of initially energeti
c O(D-1) atoms in bath gas of N-2 molecules are carried out. The results ar
e in excellent agreement with measurements of the translational energy rela
xation of O(D-1) atoms produced in the 157 nm photodissociation of O-2 and
the 193 nm photodissociation of N2O in an N-2 atmosphere.