3D-QSAR refers to the application of force field calculations, requiring the three-dimensional structure of a given set of small molecules (training set) with known activities. The training set needs to be superimposed (aligned) by experimental data (based on ligand-protein crystallography) or molecular superposition software. It uses calculated potentials, such as Lennard-Jones potentials rather than experimental constants, but related to the entire molecule, rather than individual substituents. It studies the spatial field (the shape of the molecule) and the electrostatic field related to each other through partial least squares regression (PLS). 3D-QSAR https://www.computabio.com/3d-qsar-service.html