Editing MotiveValidator:Principles (section)

=Validation results=
Each molecule is evaluated depending on how it fares during the validation analyses described above. If no issues are found during the validation analyses, the molecule is marked as having ''complete structure and correct chirality''. Validated molecules exhibiting an error in at least one of the ''Completeness'' analyses are denoted as ''incomplete'', whereas the remaining molecules are reported as ''complete''. If no issues are detected during the ''Chirality'' analyses, the validated molecule is marked as having ''Correct chirality'', whereas the remaining molecules are marked as having ''Wrong chirality''. When issues are found during an ''Advanced'' analysis, a warning is reported: Substitution, Foreign atom, Different naming, Zero RMSD or Alternate conformations. Each type of issue encountered during validation has a specific color code. 

Some types of chirality errors do not constitute real issues, but are artifacts of the automated chirality determination procedure. Specifically, an error in planar chirality may just mean that the chiral atom is situated slightly above or below the plane compared to its equivalent in the model from wwPDB CCD. Further, an error in high order chirality often marks the involvement of phosphate O atoms in salt or ester formation, or merely a different PDB format identification of phosphate O atoms of the validated molecule compared to the model. Therefore, if the validated molecule is found to have planar or high order chirality errors, but no other type of chirality issues, the molecule is marked as having ''Correct chirality (tolerant)''.

While the results of the ''Advanced'' analyses have no bearing over the chemical soundness of the validated molecules, they indicate that further, especially automated processing of these structures can be very problematic. Comparison between the structures of molecules with the same annotation (3-letter code) from different PDB entries might even be impossible in the presence of a substitution, as the corresponding atoms have different chemical elements. PDB atom names cannot be used straightforwardly, since even element symbols can differ and atoms can be formally included in neighboring residues.