Extended Data Table 1 | Spin Hamiltonian coefficients, spin-structure frequencies and spin-frequency derivativesE′k (Ek) are the updated coefficients of the spin Hamiltonian^35 of the upper (lower) rotational level, in MHz. f(thespin,or)i are theoretical spin frequencies in MHz. γ are the dimensionless sensitivities of
the spin frequencies to the spin Hamiltonian coefficients. γfik′′,s=∂(thepin,or)ik/∂E refer to the upper state and γfik,s=−∂/(thepin,or)ik∂E to the lower state. The entries for line 19 are decimal representations of
rational values (see equation (6) in ref.^37 ). Note that because of the tracelessness of the spin Hamiltonian^36 , ∑=iidγik, 0 and ∑iidγ′′ik,=0, where di = (2F(i) + 1)/36 and d′i = (2F′(i) + 1)/36 are the
degeneracies of the respective spin states, and the sum is over the ten favoured transitions i = 12, ..., 21.