One thing to note in the original code of energy.h is that there is an
overt difference in the expression so that the variable time_step only
appears in the rotational energy term:
*/
MDINLINE void add_kinetic_energy(Particle *p1)
{
/* kinetic energy */
energy.data.e[0] += (SQR(p1->m.v[0]) + SQR(p1->m.v[1]) +
SQR(p1->m.v[2]))*PMASS(*p1);
#ifdef ROTATION
/* the rotational part is added to the total kinetic energy;
at the moment, we assume unit inertia tensor I=(1,1,1) */
energy.data.e[0] += (SQR(p1->m.omega[0]) + SQR(p1->m.omega[1]) +
SQR(p1->m.omega[2]))*time_step*time_step;
#endif
}
If anyone can comment in regards to this I would be happy to hear it.