However , each rotational state exhibits fine and hyperfine structure , due to the spin - orbit and electron - nucleus interactions , respectively .
The ground vibrational and electronic ( vibronic ) state exhibits a simple rigid rotor - type rotational spectrum .
Each rotational state exhibits fine and hyperfine structure , due to the spin - orbit and electron - nucleus interactions , respectively .
The ground vibrational and electronic ( vibronic ) state exhibits a simple rigid rotor - type rotational spectrum .