README.md in eulim-0.0.5 vs README.md in eulim-0.0.6

@@ -34,10 +34,12 @@
 * H, He, Li, Be, B, C, N, O, F, Ne, Na, Mg, Al, Si, P, S, Cl, Ar, K , Ca, Sc, Ti, V, Cr, Mn, Fe, Co, Ni
 * symbol, name, atomic_number, atomic_mass
 
 #### Compound
 
+* molecular_mass
+
 ## Usage
 
 	$ Eulim::Chemistry::Element.get_by_symbol("H")
 	=> #<Eulim::Chemistry::Element: @symbol="H", @name="Hydrogen", @atomic_number=1, @atomic_mass=1.008>
 
@@ -47,9 +49,12 @@
 	$ Eulim::Chemistry::Compound.new("CaCO3")
 	=> #<Eulim::Chemistry::Compound: @formula="CaCO3">
 
 	$ Eulim::Chemistry::Compound.new("CaCO3").elements
 	=> [#<Eulim::Chemistry::Element: @symbol="Ca", @name="Calcium", @atomic_number=20, @atomic_mass=40.078>, #<Eulim::Chemistry::Element: @symbol="C", @name="Carbon", @atomic_number=6, @atomic_mass=12.0107>, #<Eulim::Chemistry::Element: @symbol="O", @name="Oxygen", @atomic_number=8, @atomic_mass=15.9996>]
+
+	$ Eulim::Chemistry::Compound.new("Be3Al2(SiO3)6").molecular_mass
+	=> 537.505346
 	
 ## Development
 
 After checking out the repo, run `bin/setup` to install dependencies. Then, run `rake spec` to run the tests. You can also run `bin/console` for an interactive prompt that will allow you to experiment.