CHEM 550 Problem Set #7
Due Mon Dec 1 at 5pm –PUT IN ANDREAS TILLACKS MAILBOX
Levine Exercises:
10.18 Spin functions
11.30 Terms, levels, states of carbon
Additional Problems
Spin
1) a) Write out all of the allowed wave-functions for the first excited state of the He atom
including electron spin. Which functions correspond to triplet states and which to singlet
states.
b) List 5 particles that are Fermions. List 5 that are Bosons. (Google is fair game if you
don’t happen to know this many particles off the top of your head!). What do you notice
as far as a trend goes for the ‘fundamental’ particles.
Term symbol practice
1) Derive (do not just state) the possible term symbols for the 1s
2
2s
2
2p
3
configuration of
a nitrogen atom.
Qualitative Material
2) a) Explain why the Hartree-Fock SCF method doesn’t obtain the exact ground state
energy even though it incorporates an interelectron repulsion term into the Hamiltonian.
b) Explain why the energy of an orbital depend on l for electrons in atoms other than
hydrogen? Annotate your discussion with a plot of the radial wave functions for 3s, 3p
and 3d.
c) Rationalize why, all other things being equal, parallel (unpaired) spins generally (not
always) produce states of lower energy that states with antiparallel (paired) (Hund’s rule)