LIST OF PREVIOUS LESSONS

• Physical Chemistry: The Simple Hückel Method (Part V)
• Physical Chemistry: The Simple Hückel Method (Part IV)
• Physical Chemistry: The Simple Hückel Method (Part III)
• Physical Chemistry: The Simple Hückel Method (Part II)
• Physical Chemistry: The Simple Hückel Method (Part I)

AO #	Atom	Type	n	l	m	z
1	C	2s	2	0	0	1.625
2	C	2pz	2	1	0	1.625
3	C	2px	2	1	(1)	1.625
4	C	2py	2	1	(1)	1.625
5	H	1s	1	0	0	1.200
6	H	1s	1	0	0	1.200
7	H	1s	1	0	0	1.200
8	H	1s	1	0	0	1.200

Summary

• All valence electrons are considered.
• Approximate description of the atomic orbitals using Slater Type functions.
• Calculation of the overlap integrals numerically
• Coloumb integrals estimated using experimental ionization energies.
• Resonance integrals empirically calculated from the product of the average ionization energies (Coulomb integrals) and the overlap integral scaled by an empirical constant K.

REFERENCES

Wheland’s method

G. W. Wheland .The Quantum Mechanics of Unsaturated and Aromatic Molecules: A Comparison of Two Methods of Treatment. J. Chem. Phys. 2, 474 (1934).

Hoffman’s Extended Huckel method

Hoffmann, R. (1963). “An Extended Hückel Theory. Hydrocarbons.”. J. Chem. Phys. 39 (6): 1397–1412.

R. Hoffmann and W. N. Lipscomb (1962). “Boron Hydrides: LCAO—MO and Resonance Studies”. J. Chem. Phys. 37 (12): 2872.

Fenske-Hall Method

Hall, M. B. and Fenske, R. F. (1972). “Electronic structure and bonding in methyl- and perfluoromethyl(pentacarbonyl)manganese”. Inorg. Chem. 11 (4): 768.