They include rotational, vibrational, electronic and nuclear modes.

Vibrational or rotational modes, which have relatively high energy, are excited or decay through the interaction with photons.

Because of quantum mechanical selection rules, only certain rotational modes are permitted.

The protein provides a large number of pathways which can become excited in vibrational, rotational, and electromagnetic modes.

Heating will also cause, through equipartitioning, the energy associated with vibrational and rotational modes to increase.

The assumption of spherical particles is necessary so that there are no rotational modes allowed, unlike in a diatomic gas.

In other words, during each oscillation some of the energy in the translational mode leaks into the rotational mode.

These rotational modes in turn have some particular rate of energy-equilibration with the translational kinetic energy in the gas.

In it you derive the criteria for stability and frequency for different rotational modes.

For the folding to stabilize, many of these rotational modes must be cooled, so that the hydrogen bonding can hold the structure in place.