correct form of hamiltonian function for conservative system phys rev vol 32 p 812 1928 e bright wilson jr and j b howard the vibration rotation energy levels of polyatomic molecules i mathematical theory of semirigid asymmetrical top molecules j chem phys vol 4 pp 260 268 1936 b t darling and d m dennison the water vapor molecule phys rev vol 57 pp 128 139 1940 j k g watson simplification of the molecular vibration rotation hamiltonian mol phys vol 15 479 490 1968 l c biedenham and j d louck angular momentum in quantum physics volume 8 of encyclopedia of mathematics addison wesley reading 1981 u201c numerical optimization u201d as used herein may be any suitable numerical optimization technique including but not limited to combinatorial methods derivative free methods first order methods second order methods etc particular methods of numerical optimization include but are not limited to gradient descent also known as u201c steepest descent u201d or u201c steepest ascent u201d nelder mead methods or u201c amoeba methods u201d subgradient methods simplex methods ellipsoid methods bundle methods newton 39 s method quasi newton methods interior point methods conjugate gradient methods line searching etc see e g r fletcher u201c practical methods of optimization u201d john wiley and sons new york 1987 see also j nocedal and s wright numerical optimization springer verlag 2d ed 2006 as schematically illustrated in fig1 the present invention provides a method of selecting a molecular structure having a physical property of interest comprising a providing a set of chemical substituents including an information set for each of said substituents e g the information set comprising chemical valency bond lengths and bond.