In the following model, the sp2 carbon atoms are dark gray and the hydrogens are cyan. The different phases of the molecular orbitals are colored red and blue and are separated by nodal surfaces at which electron density is zero. Orbital amplitude and transparency may be changed by clicking appropriate buttons under the display. π-orbitals are formed by overlap of p-orbitals having like phases. The lowest energy π-orbital, π1, has a single nodal plane, that of the atoms of the ring. Higher energy π-orbitals may be viewed by clicking appropriate buttons under the display. An increasing number of nodes parallels the increase in energy. In two of the orbitals, a node passes through two carbon atoms, so the π electron density at those sites is zero. The three lowest energy π-orbitals, π1, π2 & π3 are bonding. The three higher energy orbitals, π4*, π5* & π6* are antibonding. The molecules can be rotated by clicking on the structure and dragging the mouse. Holding the shift key during this operation allows zooming.
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