Non-invasive fibre optic Fourier transform-infrared reflectance spectroscopy on painted layers Identification of materials by means of principal component analysis and Mahalanobis distance

The present article demonstrates how the recently developed structure representation using quantum topology (StruQT) approach enables easier interpretation and discovery of 3D quantitative structure-property relationships (QSPR) in calculated reaction pathways from ab initio methods. StruQT is based on the atoms in molecules (AIM) theory where the use of critical points in the electron density distribution is of central importance. The reasons for using AIM theory are: (a) critical points provide a finite and highly compressed representation of a continuous 3D scalar field, (b) it is firmly rooted in quantum mechanics and (c) it provides a link between traditional chemical concepts and quantum mechanics which is crucial for the interpretation of QSPR models.