A note on quasiequlibrium vibrational distributions of polyatomic molecules

The quasiequilibrium vibrational distribution characterizing the intermediate relaxation stage established by near-resonant, inter- and intra-mode collisional VV exchanges in polyatomic molecules is derived through the maximum entropy principle. When a unique set of dominant energy transfer pathways can be identified one obtains familiar relationships between vibrational mode temperatures. When many nearly equivalent sets are possible the analysis suggests a common vibrational temperature. The validity of the assumptions and the applicability of the results for explaining energy localization in polyatomic molecules following laser excitation are considered.