On the competition between linear and perpendicular isomers in photodynamics of cationic argon trimers.

Photoabsorption and subsequent photodissociation of two structural isomers of Ar(3) (+) are studied via semiclassical non-adiabatic dynamics simulations. Several experimental observables are simulated under various plausible experimental conditions with the main emphasis on the differences between the data produced for the two isomers. They include photoabsorption cross section, total kinetic energy released, fragments kinetic energy distributions, and distribution of the total kinetic energy among photofragments represented via Dalitz plots. The ability of the parameters to discriminate between the two isomers is analyzed through a thorough comparison with available experimental data. We show that the recently recorded experimental Dalitz plots [V. Lepère, Y. J. Picard, M. Barat, J. A. Fayeton, B. Lucas, and K. Béroff, J. Chem. Phys. 130, 194301 (2009)] correspond to a hot mixture of distorted linear-like and perpendicular-like structures where linear-like structures prevail.