Hydrogen Bonds(Home)

The main objective in developing PM6 was to improve the prediction of hydrogen bonds.  Although they are relatively weak compared to normal covalent bonds, they are essential to biochemical processes.  PM6 represents a large change from earlier NDDO methods, so to give an idea of how well or how badly hydrogen bonds are reproduced, a large number of hydrogen-bonding systems are presented here.  These cover the main types of hydrogen bonding, that is, from simple bonding of the type found in ice and sucrose, to stronger bonds of the type found in the zwitterions of the amino acids, to symmetric or almost symmetric very strong hydrogen bonds, to the knife-edge bonds which can be used for testing theoretical methods.

Comparison of PM6 and X-Ray Structures of Hydrogen-Bonded systems