ContentsPreface 1 Orbitals in Quantum-Chemical Calculations A. Introduction B. Polyelectronic Atoms C. Molecular Calculations D. Basis Sets E. Semiempirical Calculations F. Electronic Ionizations and Transitions G. Molecular-Orbital Charge Distributions H. Orbital Transformations and Calculations Not Involving Orbitals References 2 Electron Densities and Shapes in Atoms and Molecules A. Some Typical Atoms B. Some Typical Molecules C. Representation of Orbital Shapes in Molecules D. Effect of Poor Basis Sets on Electron-Density Distributions References 3 Cross-Sectional Plots of Electron Densities A. Introduction B. Methane, Ethane, and Ethylene C. Methyl Fluoride, Methyl Chloride, Methyl Isocyanide, and Acetonitrile D. Methyl Mercaptan, Methyl Alcohol, and Dimethyl Ether E. Monomeric Lithium Fluoride and Monomeric Methyl Lithium F. Hydrogen Cyanide and Its Analog, Methinophosphide G. Ammonia, Phosphine, and Arsine ?. Methylamine, Methylphosphine, and Its Isomeric Phosphorus Ylide I. Cyclopropane, Phosphirane, and Thiirane J. Hydrogen Sulfide and Its Two Hypothetical Derivatives: H2SO and H2S02 K. Phosphorus Trifluoride and Phosphoryl Trifluoride, as well as Difluorophosphine and Difluorophosphine Oxide L. Orbital Interrelationships among Water, Formaldehyde, and Ketene M. Monomeric Borane and Diborane N. Chlorosilane and the Role of d Orbitals in Charge Transfer to Third-Period Atoms 0. Phosphorus Pentafluoride P. Internal Rotation in Molecules, with Emphasis on Diphosphine References Index