On Wed, Aug 11, 2010 at 3:53 PM, Brian Granger <elliso...@gmail.com> wrote: > > > On Wed, Aug 11, 2010 at 3:35 PM, Ondrej Certik <ond...@certik.cz> wrote: >> >> On Wed, Aug 11, 2010 at 3:33 PM, Ondrej Certik <ond...@certik.cz> wrote: >> > Hi, >> > >> > I started implementing the energies, for the hydrogen atom first: >> > >> > >> > http://github.com/certik/sympy/commit/a9d53910dd2f0bfe9fe3a25614f3586faaadded0 >> > >> > no tests/doctests so far, but I have a question: what would be the >> > best API for that? >> >> In particular, notice that I am using Hartree atomic units for >> energies, but SI (or any units actually) for the wavefunction. So the >> wave function contains the bohr radius "a", while the energies only >> contain the Z. I also need speed of light for the dirac energies. >> >> >> Should we use (Hartree) atomic units, or SI units? We should use one >> sets of units for everything. >> > > I would use atomic units for everything. But. Hartree units, you mean that > the ground state energy is -1/2.
Yep: http://en.wikipedia.org/wiki/Atomic_units > >> >> I think we should implement this units independent, and use symbols >> like "c", "a", "Z", and then also allow some simplified version that >> gives you the energies in atomic units, as that's what is used most >> often. >> >> What do you think? >> > > Anytime you manipulate these things symbolically, you want atomic units, so > I would go with that as the default. I would then possible put in static > conversion factors for the various common other units. Yes, let's do that. Everybody knows how to use atomic units. With this Bohr radius, as we have in the hydrogen solutions, it's all messy. I'll fix it. Ondrej -- You received this message because you are subscribed to the Google Groups "sympy-patches" group. To post to this group, send email to sympy-patc...@googlegroups.com. To unsubscribe from this group, send email to sympy-patches+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/sympy-patches?hl=en.
