## Quantum numbers

The quantum numbers are given in the following order:
(or ); and (or ; ); ; ...
for the upper state followed immediately by those for the lower state (see also below).

- is the total rotational angular momentum excluding electron and nuclear spins. For singlet molecules, , the total rotational angular momentum including electron spin, is equal to .
- and are the projections of onto the A and C inertial axes, respectively. For symmetric top molecules, only is needed (instead of and ) along with or , which designate the parity; if redundant, the latter might be omitted. Instead of , or may be used for linear molecules.
- is a state number! It specifies different vibrational or electronic states. It may also be used to distinguish between different species that have been fit simultaneously. Details on the meaning of the state numbers are given in the documentation! Note: More than one state number may be needed to designate one vibrational state - this is the case, for example, for a degenerate (e.g. bending) state of a symmetric top molecule!
- ... designate spin quanta. In general, the electron spin is coupled to the rotational angular momentum first, followed by nuclear spins. In this case =

Very Important:

Exactly two characters are available for each quantum number. Therefore, half integer quanta are rounded up! In addition, capital letters are used to indicate quantum numbers larger than 99. E.g. A0 is 100, Z9 is 359. Small types are used to signal corresponding negative quantum numbers.

Since the program was written for asymmetric top molecules, some of the quantum numbers may be redundant.

Six quantum numbers are available at most to describe the upper and lower state, respectively. In case more quantum numbers are needed, even if some of them are redundant, the only spin designating quantum numbers are , , were is an aggregate spin number (see below).