particles Particles module. Particle Arbitrary particle. Parameters: Name Type Description Default charge int Charge of the particle in atomic units. required mass int Mass of the particle in atomic units. required Electron Bases: Particle Electron. Notes \[q = -1e\] \[m = 1m_e\] Proton Bases: Particle Proton. Notes \[q = +1e\] \[m = 1836 m_e\]