  We consider the roaming mechanism for chemical reactions under the
nonholonomic constraint of constant kinetic energy. Our study is carried out in
the context of the Hamiltonian isokinetic thermostat applied to Chesnavich's
model for an ion-molecule reaction. Through an analysis of phase space
structures we show that imposing the nonholonomic constraint does not prevent
the system from exhibiting roaming dynamics, and that the origin of the roaming
mechanism turns out to be analogous to that found in the previously studied
Hamiltonian case.
