p electron bond order


We can also define a quantity which measures the strength of a p-electron bond between two atoms.  This quantity depends on the electron density which is shared between two atoms.


To calculate the p-bond order between a pair of atoms, add together the contributions to bonding from all the occupied p MOs.


p electron bond order for a-b bond (pab):



again ni is the number of electrons in molecular orbital i.  If all the occupied molecular orbitals have two electrons in them then ni = 2 for all the MOs, and:



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