Energy level diagram of lowest 60 hyperfine levels of ¹²C¹H. The zero reference energy is defined for the lowest CH rotational level (²Π_1/2, j = 1/2). The rotational levels are drawn to scale but the Λ-doubling and the hyperfine splittings are not shown to scale for clarity reasons. It should be noted that f levels are lower than e in the F₁ spin-orbit manifold but the reverse is true in the F₂ spin-orbit manifold. Regarding the energy order of the hyperfine levels, higher F corresponds to higher energy in F₂ but the reverse is true in F₁ (with the exception for the lowest Λ-doublet shown in red). The total parity (±) is also shown.