[Chimera-users] Principal axis of inertia

[Greg Couch]

On Mon, 18 May 2009, Eric Pettersen wrote:

> On May 15, 2009, at 10:40 AM, Tom Goddard wrote:
>
>> Hi Armida,
>> 
>> Elaine is right.  The atoms are weighted by their mass, carbon counts
>> 12 times more than a hydrogen.  Isotopic abundances are not considered
>> -- I think Chimera's atom.element.mass is just the number of protons plus 
>> neutrons in the post prevalent isotope.
>
> The mass is the number from the periodic table of the elements -- which is an 
> average across isotopes.
>
> --Eric

More explicitly, the atom's mass is the "standard atomic weight" as given
in <http://en.wikipedia.org/wiki/List_of_elements_by_atomic_weight>.

         - Greg