The random Brownian motion of gas molecules is phenomenologicallly described by the Langevin equation, but its underlying dynamical mechanism remains unclear. This paper proposes a capacitor oscillation model in hydrogen molecular plasma to investigate the origin of Brownian frequency. In this model, excited hydrogen molecules are treated as coherent electron–proton capacitor oscillators generated by orbital nutation. Their collective charge oscillation gives rise to both electron and proton Langmuir frequencies. The electron frequency corresponds to the conventional Langmuir frequency, while the proton Langmuir frequency is identified as the Brownian frequency associated with molecular thermal motion. This work is the second article in the framework of electron–proton orbital procession and nutation in hydrogen atoms.
Wen et al. (Sun,) studied this question.