By the way... I think the commentator in the attached perspective (http://www.sciencemag.org/content/331/6016/411.full) gets the born-oppenheimer approximation wrong... he states that :

"The BO approximation makes possible the practical application of quantum mechanics to all of molecular science. As the arrangement of the nuclei changes, the BO approximation postulates that the electrons will remain in a particular quantum state. "

When the BO approximation is the opposite : The atoms DONT move while the electrons DO (relatively speaking) because of their vast difference in mass. That is... the electrons are little bullets whizzing around at top speed, whereas the atoms are massive aircraft carriers in terms of mass (note: this is not meant to be even a remotely accurate analogy, but it's the general idea). You'd think that SCIENCE, of all journals, would get the Born-Oppenheimer approximation right !

Note: That in the second step of a typical quantum mech. calculation (e.g. a geometry optimization), you then use the average field generated in the first part to move the atoms (if they need to move in the particular calculation). Then you iterate to self-consistency.