Really minor, but h/2pi (“h-bar”) is not Planck’s Constant, h is. It would be more correct to say that in atomic units, Plank’s Constant is set equal to 2pi or, equivalently, h-bar is set equal to one.
Back in my quantum days, we were REAL manly men, eschewing the use of such paltry units as eVs; REAL MEN used Hartrees.
Yeah, but what’s a couple of pi among friends? Particle physicists refer to both h and h/2pi (“h-bar”) as “Planck’s constant”. We are very sloppy that way.
As for Hartrees: Fock you.
(Note to moderators: please don’t ban me, this is a really hilarious physics pun. Really. It is. Ask anyone. I’m sure SY is not offended at all, but is indeed howling with laughter.)
Not to jump on Dex’ toes, but I’d say you don’t have to worry, Karen.
You see, when Ed approves us to be moderators, he makes us buy The Big Book O’ Obscure Insider Physics Humor, along with a variety of similar tomes. Why, just the other day a quick look at one of the books saved me from impropertly warning a transvestite who signed off her post “Oh, tuck!”
So Karen, getting tired of writing these mailbag responses? Every time you delve into the finer details of physics, some schmuck* has to come along and criticize your phrasing. Gee, you’d think a particle physicist could get a break that nobody would really know the details, but Noooo. 
Just wanted to say thanks, so you wouldn’t feel completely unappreciated.
(No offense for the schmucks out there. 
)
Of course I’m not offended. NOTHING offends me.
Self-consistency is the hobgoblin of small minds (ouch!). But you particle types are notorious for waving off anything less than an order of magnitude.
Two famous elementary particle physicist quotes:
“One equals two for large values of one.”
“The energy of an electron, though infinite, is small.”
The latter, if my dim memory is correct, came from Steven Weinberg.
Um, I guess I’m just showing my youth here, but Hartrees? Fock? I’m guessing, from the context, that a Hartree is a unit of energy comparable to an eV, and suitible for use in particle physics, and I’d presume that a Fock is some related unit, but what are they?
I’ve never actually heard of Hartrees, but Hartree was a guy and Fock was a guy and together they invented the Hartree-Fock Equations, the explanations of which take up 200 pages in my Solid State Physics book. I’m sure condensed matter physicists revere Hartree and Fock like gods, but to me they represent one miserable semester of graduate school torture. Fock both of them!
And in fact, all I remember about Hartree-Fock equations is their name. (I’m sure not going to re-read those 200 pages to refresh my memory.)
The Hartree-Fock equations are a way to approximate a multiparticle Hamiltonian (i.e., the basic equation to give energy levels) using a self-consistent field approach. Though Karen makes it sound complicated, it really isn’t; it’s just a pain in the ass to learn when you’re not going to do solid-state or chemical physics, so I sympathize with her. Hey, I hated having to study relativistic quantum theory, and I’m sure that it’s mamma’s milk to her.
The main application is to characterize atomic and molecular energy levels, chemical binding, electron/molecule scattering and the like. Quantum chemists use a convenient unit, the Hartree, to express energies. In the sense that it’s a unit of energy, it’s just like an eV. I forget the conversion factor (it’s been a long time since I worked as a scientist), but I think it’s 13.7 eV to the Hartree. An odd number, but a sensible one when you look at the ionization potential of a hydrogen atom.
Particle physicists have their own odd units- I think the length unit is the Fermi?
The Fermi doesn’t count because 1 Fermi (abbreviation = fm) = 1 femtometer (abbreviation = fm). It’s like saying “micron” instead of “micrometer”.
OK, I can see the usefulness of an energy unit equal to 13.6 eV. I agree with Karen, though… Solid state is icky. Give me a nice, clean black hole any day.