Atomic Structures of all the Twenty Essential Amino Acids and a   Tripeptide, with Bond Lengths as Sums of Atomic Covalent Radii
  Recently, the bond lengths of the molecular components of nucleic acids and of caffeine and related molecules were shown to be sums of the appropriate covalent radii of the adjacent atoms. Thus, each atom was shown to have its specific contribution to the bond length. This enabled establishing their atomic structures for the first time. In this work, the known bond lengths for amino acids and the peptide bond are similarly shown to be sums of the atomic covalent radii. Based on this result, the atomic structures of all the twenty essential amino acids and a tripeptide have been presented. 
Raji Heyrovska