Comment on A magnetic velocity Verlet method [Am. J. Phys. 88, 1075 (2020)]

The implicit midpoint method described by Chambliss and Franklin [Am. J. Phys. 88, 1075 (2020)] is known not to exactly conserve energy for a spatially varying magnetic field, nor does it conserve angular momentum in a constant magnetic field. It is, therefore, not competitive with the widely used Boris solver in plasma physics, which conserves both. (C) 2021 Published under an exclusive license by American Association of Physics Teachers.

Automated summary

The implicit midpoint method described by Chambliss and Franklin does not exactly conserve energy for spatially varying magnetic fields or conserve angular momentum in a constant magnetic field. As a result, it is not competitive with the widely used Boris solver in plasma physics, which conserves both energy and angular momentum.