Lecture 23: Introduction to Valence Bond Theory The material in this lecture covers the following in Atkins. 14 Molecular structure Valence-bond theory.

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Lecture 23: Introduction to Valence Bond Theory The material in this lecture covers the following in Atkins. 14 Molecular structure Valence-bond theory 14.1 The hydrogen molecule (a) The spatial wavefunction (b) The role of the electron spin Lecture on-line Introduction to Valence Bond Theory (PowerPoint) Introduction to Valence Bond Theory (PDF) Handout for this lecture

It is very difficult to represent valence-bond wavefunctions because they refer to two electrons simultaneously. However, this illustration is an attempt. The atomic orbital for electron 1 is represented by the black contours, and that of electron 2 is represented by the green contours. The top illustration represents A(1)B(2), and the middle illustration represents the contribution A(2)B(1). When the two contributions are superimposed, there is interference between the black contributions and between the green contributions, resulting in an enhanced (two-electron) density in the internuclear region.