18 May
2009
18 May
'09
9:26 p.m.
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 Eric Pettersen UCSF Computer Graphics Lab http://www.cgl.ucsf.edu