Harnessing the Power of Curvilinear Internal Coordinates: from Molecular Structure Prediction to Vibrational Spectroscopy

Different standard VPT2 codes employ Cartesian coordinates for the computation of rotational and vibrational spectroscopic parameters. However, curvilinear internal coordinates offer a number of advantages provided that a general non-redundant set of coordinates can be built and employed in an unsupervised workflow. In the present paper I summarize the main results and perspectives of a general engine employing curvilinear internal coordinates and perturbation theory for the computation of rotational and vibrational spectroscopic parameters of large molecules beyond the conventional rigid rotor/harmonic oscillator model. Some examples concerning biomolecule building blocks are discussed in some detail in order to better analyze the performance of the proposed strategy.