Fixed incorrect abbreviations for charge units

wrappers/python/simtk/unit/baseunit.py

@@ -26,7 +26,7 @@ class BaseUnit(object):
          - self: The newly created BaseUnit.
          - base_dim: (BaseDimension) The dimension of the new unit, e.g. 'mass'
          - name: (string) Name of the unit, e.g. "kilogram"
-         - symbol: (string) Symbol for the unit, e.g. 'kg'.  This symobol will
+         - symbol: (string) Symbol for the unit, e.g. 'kg'.  This symbol will appear in
             Quantity string descriptions.
         """
         self.dimension = base_dim

wrappers/python/simtk/unit/unit_definitions.py

@@ -108,10 +108,10 @@ planck_temperature_base_unit.define_conversion_factor_to(kelvin_base_unit, 1.416
 ### CHARGE ###
 ##############
 
-elementary_charge_base_unit = BaseUnit(charge_dimension, "elementary charge", "q")
+elementary_charge_base_unit = BaseUnit(charge_dimension, "elementary charge", "e")
 elementary_charges = elementary_charge = Unit({elementary_charge_base_unit: 1.0})
 
-coulomb_base_unit = BaseUnit(charge_dimension, "elementary charge", "q")
+coulomb_base_unit = BaseUnit(charge_dimension, "elementary charge", "C")
 # Exact conversion factor
 coulomb_base_unit.define_conversion_factor_to(elementary_charge_base_unit, 6.24150962915265e18)
 coulombs = coulomb = Unit({coulomb_base_unit: 1.0})