asSym is (for diatomic molecules with a centre of inversion) the symmetry of the rovibronic wavefunction: 'a' or 's' such that the total wavefunction including nuclear spin is symmetric or antisymmetric with respect to permutation of the identical nuclei (P12), according to whether they are bosons or fermions respectively.
ElecStateLabel is a label identifying the electronic state: X, A, a, B, etc.
F is the quantum number associated with the total angular momentum including nuclear spin: F = J + I1 if only one such coupling is resolved, F = F1 + I2 if both couplings are resolved. For identical nuclei, F = F + I, where I is the total nuclear spin angular momentum formed by coupling both spins.
F1 is the intermediate angular momentum quantum number associated with the coupling of the rotational angular momentum and nuclear spin of nucleus 1 where two such couplings are resolved: F1 = J + I1; F1 is often not a good quantum number.
I is a nuclear spin quantum number corresponding to the coupling of the nuclear spin angular momenta of two identical nuclei, I = I1 + I2.
J is the quantum number associated with the total angular momentum excluding nuclear spin, J.
kronigParity is the 'rotationless' parity: the parity of the total molecular wavefunction excluding nuclear spin and rotation with respect to inversion through the molecular centre of mass of all particles' coordinates in the laboratory coordinate system. For a closed shell, diatomic molecule (Σ+ electronic state), kronigParity is 'e' for all rotational states.
parity is the total parity: the parity of the total molecular wavefunction (excluding nuclear spin) with respect to inversion through the molecular centre of mass of all particles' coordinates in the laboratory coordinate system, the E* operation.
r is a named, positive integer label identifying the state if no other good quantum numbers or symmetries are known.
v is the vibrational quantum number.