After the initial bimolecular collision of A and B an energetically excited reaction intermediate is formed, then, it collides with a M body, in a second bimolecular reaction, transferring the excess energy to it.
12.
But modeling a bimolecular reaction inside a voxel using the SSA s reaction probability rate will be physically valid only if the reactant molecules are dilute inside the voxel, and that requires the voxels to be much " larger " than the reactant molecules.
13.
This can be the case when studying a bimolecular reaction and a simultaneous hydrolysis ( which can be treated as pseudo order one ) takes place : the hydrolysis complicates the study of the reaction kinetics, because some reactant is being " spent " in a parallel reaction.
14.
A reaction can also have an " undefined " reaction order with respect to a reactant if the rate is not simply proportional to some power of the concentration of that reactant; for example, one cannot talk about reaction order in the rate equation for a bimolecular reaction between adsorbed molecules:
15.
Called the "'small-voxel tracking algorithm "'( SVTA ), it subdivides the system volume into voxels that are smaller than the reactant molecules, and hence " much " smaller than the voxels used in the RD-SSA . Diffusion is therefore modeled much more accurately in the SVTA than in the RD-SSA . But inside such small voxels, the SSA s bimolecular reaction probability rate will no longer be physically valid.
