#
`SPIN`

The spin matrix, defined as the difference between the alpha and beta
density matrices, is to be printed. If the system has a closed-shell
ground state, e.g. methane run UHF, the spin matrix will be null.
If `SPIN` is not requested in a UHF calculation, then the diagonal of the
spin matrix, that is the spin density on the atomic orbitals, will be printed.