In fact, real chemical bonds usually fall somewhere in between. When two atoms come together, their atomic orbitals combine to form molecular orbitals. For each two atomic orbitals combined, two ...

Structure of Iridium (Ir) dimer complex showing an Ir-Ir bonding molecular orbital populated (left) and an Ir-Ir anti-bonding molecular orbital depopulated (right) by optical excitation ...

Now, a team of researchers from Hokkaido University has isolated a compound in which a single electron is shared between two carbon atoms in a remarkably stable covalent bond, known as a sigma bond.