Atomic coordinates and structure factors for two helical configurations of polypeptide chains

During recent years we have been gathering information about interatomic distances, bond angles, and other properties of simple substances related to proteins, and have been attempting to formulate configurations of the polypeptide chain that are compatible with this information and that might constitute a structural feature of proteins. We have reported the discovery of two helical configurations that satisfy these conditions. (1,2) In the following paragraphs we discuss the atomic positions for these configurations, and their form factors for diffraction of x-rays in the equatorial direction.