Valence Shell Electron Pair Repulsion (VSEPR) Theory proposes that molecules and ions adopt 3D shapes that minimize repulsion between the bonding pairs in Local Bond Theory Lewis Structures.
Here is a good resource from the Open Educational Resource OpenSTAX Chemistry.

This is a part of a series of pages that serve as a static set of URLs to be used in the references section of my book Spectroscopy Theory in One Dimension through AIP Press.