(a) Double-resonance spectrum of the 3₀₃ ← 2₀₂ rotational transition of syn-glycolamide showing five different hyperfine components. The 2 ← 2 and 3 ← 2 lines were observed monitoring the hyperfine component F = 2 of the rotational transition 2₁₂ ← 2₀₂, while the 2 ← 1 was observed monitoring the hyperfine component F = 1. And also arrows, and both 4 ← 3 and 3 ← 3 were observed monitoring the F = 3 component of the same rotational transition; (b) schematic energy level diagram (in GHz) relative to the 2₀₂ energy level of syn-glycolamide from the determined molecular constants. The hyperfine splittings are shown. Arrows indicate an example of the observed (dashed arrows in garnet) and monitored (dotted arrows in blue) transitions.