Molecular Orbital Theory The goal of molecular orbital theory is to describe molecules in a similar way to how we describe atoms, that is, in terms of orbitals, orbital diagrams, and electron configurations. For example, to give you a glimpse at where we are headed, the following are orbital diagrams for O₂ and O.

O₂ O

Each line in the molecular orbital diagram represents a molecular orbital, which is the volume within which a high percentage of the negative charge generated by the electron is found. The molecular orbital volume encompasses the whole molecule. We assume that the electrons would fill the molecular orbitals of molecules like electrons fill atomic orbitals in atoms.

• The molecular orbitals are filled in a way that yields the lowest potential energy for the molecule.

• The maximum number of electrons in each molecular orbital is two. (We follow the Pauli exclusion principle.)

• Orbitals of equal energy are half filled with parallel spin before they begin to pair up. (We follow Hund's Rule.)

  
  

  to read more, please go to: http://www.mpcfaculty.net/mark_bishop/molecular_orbital_theory.htm