The Nature of Atomic Orbitals in the Bromide Anion
It is easy to use Spartan to display atomic orbitals. This makes an excellent lecture demonstration or computational laboratory for general chemistry. Create a single bromine atom on the screen by selecting Br in the entry or expert builder and then deleting the attached hydrogen. Set up a job for a single point HF/3-21G(*) calculation with a charge of -1(anion) and a multiplicity of 1(singlet).
select the option to print Orbitals & Energies in your output
and click on OK.
Now, visualize each of the orbitals
in turn. What do you see about the size and shape of the orbitals? Compare
the 3s, 2s, and 1s orbitals. Remember that red and blue are arbitrary
colors to represent the orbital phase, which can be altered by opening
the display properties window, clicking on the surface being displayed,
and then clicking the swap phase button. If you look carefully
at the 3p orbital (a mesh view is good for this) you will see that the
nodal properties expected for this orbital. The radial distribution
has a node at the nucleus and another farther away.