Algorithmic Design of Geometric Data for Molecular Potential Energy Surfaces

A code MolecGeom, based on algorithms for stepwise distortions of bond lengths, angles and dihedral polyatomic molecules, is presented. Potential energy surfaces (PESs) are curated in terms the each molecular geometry. PESs Born–Oppenheimer approximation, by which atomic nuclei within a molecule assumed stationary with respect to motion its electrons, calculated. Applications requiring involve effects nuclear properties. These include determining equilibrium geometries corresponding saddle point energies, calculating reaction rates predicting vibrational spectra. This multi-objective study focuses development new method calculation analysis geometry components incremental changes that provide comprehensive sampling while preserving precision PES points. MolecGeom applied generate geometric data calculate theoretical calculations vibrational-rotational spectra water formaldehyde. An ab initio comprising 525 2160 intramolecular configurations results frequencies agreement experiment, having errors less than 0.08% 0.8%, respectively. Vinyl alcohol, total 14 internal coordinates, generates 1458 unique geometries. Ascorbic acid, 54 1,899,776 PES.