Monte Carlo transition-state theory: XH4→XH3+H (X=C, Si)

Publisher Website
Google Scholar
Abstract
A classical variational phase‐space procedure for the computation of microcanonical dissociation rate coefficients is presented and applied to simple bond rupture in the CH4 and SiH4 systems. The method replaces the sum and density of quantum states that appear in the RRKM formalism with equivalent multidimensional phase‐space integrals which are evaluated using a Metropolis Monte Carlo sampling procedure. The computed microcanonical rate coefficients for bond rupture in CH4 and SiH4 are in good agreement with previously reported trajectory results obtained on the same potential‐energy surfaces, provided the dividing surface separating reactants and activated complex is reoptimized at each reactant internal energy. The procedure permits the entire k(E) vs E curve to be obtained in a single calculation. Consequently, the total computational time required is less than 5% of that required for the corresponding trajectory calculations.