A set of rules, formulated by Robert Corey (1897–1971) and Linus Pauling in 1951, that govern the secondary nature of proteins. The Corey–Pauling rules are concerned with the stability of structures provided by hydrogen bonds associated with the –CO-NH– peptide link. The Corey-Pauling rules state that:

1. (1) All the atoms in the peptide link lie in the same plane.

2. (2) The N, H, and O atoms in a hydrogen bond are approximately on a straight line.

3. (3) All the CO and NH groups are involved in bonding.

Two important structures in which the Corey–Pauling rules are obeyed are the alpha helix and the beta sheet.