Spectrum prediction empirical modeling methods

The most common approaches to predicting spectra are based on empirical modeling, linear additivity, database retrieval, rule sets, and semiempirical methods. The availability of large spectral libraries has proved to be a valuable resource in these studies. Although ab initio theory relating to spectrum prediction is well advanced, the theoretical equations necessary for application to real-world structures are large and complex... 

Several empirical approaches for NMR spectra prediction are based on the availability of large NMR spectral databases. By using special methods for encoding substructures that correspond to particular parts of the NMR spectrum, the correlation of substructures and partial spectra can be modeled. Substructures can be encoded by using the additive model greatly developed by Pretsch [11] and Clerc [12]. The authors represented skeleton structures and substituents by individual codes and calculation rules. A more general additive model was introduced... 

The widely used and ever-improving semi-empirical methods of quantum chemistry provided important results or, at least, prepared the way for a final theoretical treatment of chemical problems through the explicit formulation and modelling in connection with processing the experimental material. The spectrum of data spans from preliminary results to useful trend predictions to first approaches to sets of... 

---