AbstractA conformational study was carried out on the three ring‐opened structures of triplet methyloxirane with a minimal Gaussian basis set, within the unrestricted Hartree–Fock framework. For the two structuresenergy surfacesE(θ1, θ2) were generated, where θ1measures the methyl rotation and θ2is associated with the torsion about the other CC bond. For the third structurean energy hypersurfaceE(θ1, θ2, θ3) was generated, where energy was a function of methyl rotation θ1and two nonequivalent CO rotations θ2and θ3. Analysis of the surfaces revealed the locations and relative energies of the critical points (minima, saddle points, and maxima). The overall stereochemical finding was that these ring‐opened triplet C3H6O species possessed rather