Units {#units}
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Unless documented otherwise, the following units are used
- angstrom for all distances
- \f$ \frac{kcal}{mol  \unicode[serif]{xC5}}\f$ for forces/derivatives
- \f$\frac{kcal}{mol}\f$ for energies
- radians for angles. All angles are counterclockwise.
- all charges are in units of the elementary charge
- all times are in femtoseconds

