A COMBINED MODEL OF MULTI-RESONANCE SUBSPECTRA SUBSTRUCTURE AND DARC TOPOLOGICAL-STRUCTURE REPRESENTATION - LOCAL AND GLOBAL KNOWLEDGE IN THE C-13 NMR DARC DATABASE

The structural and spectral information in a C-13 NMR database can be represented by means of a model which relates substructural fragments to subspectral features for multiple resonances. The substructural part of this model contains a concise DARC description of the structural part with a partially generic ELCO(b) which is associated with all the spectral information pertaining to the focal atom (F(o)) and its neighboring carbons (A(i)). In the spectral information, the concentric environmental view is shifted from the focal atom to the neighbor positions. This leads to overlap in the views and redundancy in the information and a dissymmetrical physical perception which formally, is broader than the substructural view. New substructural/subspectral local and global knowledge functions of this model are managed with holographic techniques. Formalized local and global knowledge is described statistically by juxtaposition of the delta-C-13(Fo) x delta-C-13(Ai) correlation plane supporting the 3D occurrence distributions. Use of the inferential ability of these planes is facilitated by a table which correlates the repartitioning of the sigma- and pi-bonds in F(o)-A(i) atom pairs.