MODIFIED NOSE-HOOVER EQUATION FOR A ONE-DIMENSIONAL OSCILLATOR - ENFORCEMENT OF THE VIRIAL-THEOREM

Recently, attempts have been made to alter the equation of motion of a multiparticle system so that the temperature rather than the energy is constant. The Nose'-Hoover equation of motion is very useful for systems with a large number of particles, but, for a one-dimensional oscillator, the phase-space dynamics is not sufficiently chaotic for a fully statistical description. We propose a modified Nose-Hoover equation, obtained by enforcing the virial theorem, for which the phase-space dynamics is much more chaotic. This modified Nose-Hoover equation is easily generalized and may be useful for other systems with a small number of particles.