Quasiclassical trajectory calculations of the thermal rate coefficient for the oxygen atom + hydroxyl .fwdarw. oxygen + hydrogen atom reaction on realistic double many-body expansion potential energy surfaces for ground-state hydroperoxy

摘要

Quasi-classical trajectory calculations of the thermal rate coefficient for the title reaction have been carried out over the temperaturerange 250 5 T 5 2500 K by using two recently reported DMBE potential energy surfaces for the ground state of the hydroperoxylradical. The results are compared with each other and with experiment. The agreement is god. Our results support previoustheoretical calculations by Miller on the Melius-Blint potential energy surface in that nonstatistical ‘recrossing” effects arevery important. For the DMBE I1 (DMBE 111) potential energy surface, these nonstatistical corrections are found to increasefrom a factor of about 1.2 (1.4) at 250 K to about 2.1 (2.5) at 2500 K. However, they are considerably smaller than thenonstatistical corrections reported by Miller (factors of about 2.2 and 3.3 at the above temperatures). Although due, ofcourse, to topographical differences between the DMBE and Melius-Blint potential energy surfaces, such discrepancy stemsalso from the different definitions used for H02* complex in the simple chemical model 0 + OH e H02* -+ 0 2 + H.