 Like the halogens, when two tennessine atoms meet they are expected to form a Ts–Ts bond to give a diatomic molecule.Such molecules are commonly bound via single sigma bonds between the atoms; these are different from pi bonds, which are divided into two parts, each shifted in a direction perpendicular to the line between the atoms, and opposite one another rather than being located directly between the atoms they bind.Sigma bonding has been calculated to show a great antibonding character in the At2 molecule and is not as favorable energetically.