strained. Two orbital models were proposed to describe the bonding situation. The Coulson-Moffit model uses bent bonds. The C-C bonds are formed by overlap of two sp-hybrid orbitals. To adapt to the small bond angle, there is some rehybridization resulting in sp^~5-hybrids for the ring bonds and sp^~2 for the C-H bonds. This model resembles the banana bond model for C=C double bonds (? bonds).

Alternatively the structure can be explained with the Walsh model. Here the two sp-hybrids forming the ring bond are separated