This is another of the chemistry textbooks that can be found on the CalTech website. It was written by John D. Roberts in 1961 and had at least 14 printings. It was used for a number of years as the assigned textbook for both undergraduate and graduate students at the California Institute of Technology. The primary focus of the text is to teach students how to use the linear combination of atomic orbitals (LCAO) method.

According to the author his textbook is to teach “practicing organic chemists the simple, linear-combination-of-atomic-orbitals (LCAO), molecular-orbital method permits useful calculations of semi-empirical electronic energies of unsaturated molecules with no more than high school algebra.”

## Table of Contents on Molecular Orbital Calculations

- Preface
- 1. Atomic Orbital Models
- Hydrogen-like Orbitals
- Bond Formation Using Atomic Orbitals
- Bond Orbitals for Atoms Carrying Unshared Electron Pairs
- Orbitals for Multiple Bonds
- 2. Molecular Orbital Calculations, Electronic Energy Levels
- The Wave Equation
- Molecular Orbitals. The LCAO Method
- The Overlap Integral
- The Coulomb Integral
- The Resonance Integral
- Energy levels of H2
- Bonding and Antibonding Orbitals
- The Hydrogen Molecule
- Localized Bonds
- Ethylene by the LCAO Method
- Butadiene
- Butadiene Resonance Energy
- The Butadiene Wave Functions
- 3. Bond Orders. Free-Valence Indexes. And Charge Distributions
- The Mobile Bond Order
- The Free-Valence Index
- Charge Distributions
- Self-Consistent Fields
- 4. Application of Group Theory to Simplification of MO Determinants
- The Butadiene Determinant
- Symmetry Operations
- Character Tables
- The Trial Wave Function
- C2 Symmetry
- 5. Aromaticity. The 4n + 2 Rule
- Cyclobutadiene by the LCAO Method
- The 4n + 2 Rule
- 6. Molecules with Heteroatoms
- 7. Nonplanar Systems
- Calculation of S13
- Nonplanar Intermediates
- 8. Molecular Orbital Theory and Chemical Reactivity
- The Reactivity Problem
- Predictions Based on the Ground State
- Perturbation Methods
- Localization Procedures
- Delocalization Procedures
- Product Stabilities
- 9. Approximate Methods
- Nonbonding Molecular Orbitals
- Approximate Calculations of (E pi)
- Orientation in Aromatic Substitution
- 10. Higher-Order Calculations
- Appendix I. Solutions of Typical Exercises in the Use of the LCAO Method
- Appendix II. Reprints of Articles on LCAO Calculations
- Appendix III. General Bibliography

View this Free Online Material at the source:

Notes on Molecular Orbital Calculations