CHEM 4502 Lecture Notes - Lecture 30: Antibonding Molecular Orbital, Ellipsoidal Coordinates, Atomic Units
Document Summary
We"re finally going to use quantum mechanics to describe chemical bonding! + --> 2 nuclei and one shared electron. Finally we get to making some chemical bonds! And our first step is to make an approximation. Nuclei are so heavy that once nuclei move, the electrons respond almost instantaneously (b/c they move so fast) Analogy, when pop balloon, rubber (the electron) pops and is gone instantaneouslywater (nucleus) is slow so it retains balloon shape. Consider the mass difference between electrons and nuclei. Electrons are light, and respond quickly (in attoseconds) to changes in nuclear positions. Nuclei are much heavier and take femto- or picoseconds to move. Rather than solving the problem for both electrons and nuclei, we will freeze the nuclear positions and solve for the electronic probability density. We can then move the nuclei and repeat. We then get energy as a function of nuclear position. Consider a 1d representation of the h2 molecule ion.
