Determine the resonance energy

Question

Assignment:

1. Set up the Energy matrix for C₆H_6.

2. Solve for the molecular orbitals and normalization coefficients.

3. Determine the resonance energy.

4. C₄BNH₆ is isoelectronic to C₆H₆. If β_az= β_bz*1.2 for C-N, β_az= β_bz *0.8 N-B and , β_az = β_bz,*0.9 for B-C and β_az= β_bz, for C-C bonds. What are the new molecular orbitals?

5. Is the resonance energy higher or lower than benzene? What can one say about the aromatic character?