Local correlation domains for coupled cluster theory: optical rotation and magnetic-field perturbations.
An approach is described for selecting local-correlation orbital domains appropriate for computing response properties such as optical rotation using frequency-dependent coupled-cluster linear-response theory. This scheme is an extension of our earlier idea [N. J. Russ and T. D. Crawford, Chem. Phys. Lett., 2004, 400, 104] based on an atom-by-atom decomposition of the coupled-perturbed Hartree-Fock (CPHF) response of the component molecular orbitals to external electric and magnetic fields. We have applied this domain-selection scheme to a series of chiral molecules, including pseudo-linear structures (hydrogen molecule helices, fluoroalkanes, and [n]triangulanes), cage-like structures (beta-pinene, methylnorbornanone, and bisnoradamantan-2-one), and aromatic rings (1-phenylethanol). We find that the crossover points between the canonical- and local-correlation approaches are larger than for the conventional Boughton-Pulay domain scheme, in agreement with our earlier analysis of dipole-polarizabilities. Localization errors are reasonably small (a few percent) for pseudo-linear structures with domain sizes of approximately six to eight atoms. Cage-like molecules are significantly more problematic, requiring natural domain sizes of ten or more to obtain the most reliable localization errors.
Russ
Nicholas J
NJ
Department of Chemistry, Virginia Tech, Blacksburg, Virginia 24061, USA.
Crawford
T Daniel
TD
D000218:Adamantane / Q000737:chemistry; D000465:Algorithms; D000081008:Bicyclic Monoterpenes; D001643:Bridged Bicyclo Compounds / Q000737:chemistry; D003198:Computer Simulation; D004574:Electromagnetic Fields; D005466:Fluorocarbons / Q000737:chemistry*; D006844:Hydrocarbons, Cyclic / Q000737:chemistry*; D008956:Models, Chemical; D039821:Monoterpenes / Q000737:chemistry; D009636:Norbornanes / Q000737:chemistry; D009904:Optical Rotation; D010626:Phenylethyl Alcohol / Q000737:chemistry; D011789:Quantum Theory
C497854:3-methylene-2-norbornanone; D000081008:Bicyclic Monoterpenes; D001643:Bridged Bicyclo Compounds; D005466:Fluorocarbons; D006844:Hydrocarbons, Cyclic; D039821:Monoterpenes; D009636:Norbornanes; C010789:beta-pinene; D010626:Phenylethyl Alcohol; D000218:Adamantane