Methylamine vibration-rotation-tunneling energy levels in the Ohashi-Hougen formalism

Details: Each energy level is characterized by the quantum numbers J and K = K_a, together with the overall torsion–wagging–rotation symmetry species Γ, corresponding to an irreducible representation of the permutation–inversion group G₁₂. To distinguish between the two components of doubly degenerate levels of E₁ or E₂ symmetry with identical J and K values, the labels E₁+1 and E₁−1, or E₂+1 and E₂−1 are employed, where the +1 and −1 components correspond to k = +K and k = −K, respectively. When table includes hyperfine levels, the standard quantum number F = J + I is included in the level designation.

The correspondence between the integer symmetry identifier Sym used in the .cat file and the symmetry species Γ is summarized in the table below.