Editing ChargeCalculator:Motivation (section)

=QSPR and QSAR modelling=

The main concept behind Quantitative Structure-Property Relationships (QSPR) is that different molecular structures have different properties, and thus a (generally physico-chemical) property of interest can be represented as a function of descriptors derived from the molecular structure. In Quantitative Structure-Activity Relationships (QSAR) modelling, the property of interest is the molecule's activity in a certain context (e.g., biological activity).

Atomic charges are used as descriptors in various QSPR/QSAR models, generally in combination with other descriptors (based on the atomic composition, molecular topology, 3D structure, electronic structure, etc.). Some properties correlate with atomic charges better, and will be more easily predicted by QSPR models that rely on atomic charges as descriptors. For example, it is possible to predict dissociation constants by QSPR models which use only atomic charge descriptors, whereas predicting properties related to toxicity require several different kinds of descriptors.