Magnetizability and rotational g tensors for density fitted local secondorder MøllerPlesset perturbation theory using gaugeincluding atomic orbitals
Abstract
In this paper, we present theory and implementation of an efficient program for calculating magnetizabilities and rotational g tensors of closedshell molecules at the level of local secondorder MøllerPlesset perturbation theory (MP2) using London orbitals. Density fitting is employed to factorize the electron repulsion integrals with ordinary Gaussians as fitting functions. The presented program for the calculation of magnetizabilities and rotational g tensors is based on a previous implementation of NMR shielding tensors reported by S. Loibl and M. Schütz [J. Chem. Phys. 137, 084107 (2012)]. Extensive test calculations show (i) that the errors introduced by density fitting are negligible, and (ii) that the errors of the local approximation are still rather small, although larger than for nuclear magnetic resonance (NMR) shielding tensors. Electron correlation effects for magnetizabilities are tiny for most of the molecules considered here. MP2 appears to overestimate the correlation contribution of magnetizabilities such that it does not constitute an improvement over HartreeFock (when comparing to higherorder methods like CCSD(T)). For rotational g tensors the situation is different and MP2 provides a significant improvement in accuracy over HartreeFock. The computational performance of the new program was tested for two extended systems, the larger comprising about 2200 basismore »
 Authors:
 Institute of Physical and Theoretical Chemistry, University of Regensburg, Universitätsstraße 31, D93040 Regensburg (Germany)
 Publication Date:
 OSTI Identifier:
 22308987
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Journal of Chemical Physics; Journal Volume: 141; Journal Issue: 2; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; ACCURACY; DENSITY; ELECTRON CORRELATION; ELECTRONS; HARTREEFOCK METHOD; MOLECULES; NUCLEAR MAGNETIC RESONANCE; PERTURBATION THEORY; TENSORS
Citation Formats
Loibl, Stefan, and Schütz, Martin, Email: martin.schuetz@chemie.uniregensburg.de. Magnetizability and rotational g tensors for density fitted local secondorder MøllerPlesset perturbation theory using gaugeincluding atomic orbitals. United States: N. p., 2014.
Web. doi:10.1063/1.4884959.
Loibl, Stefan, & Schütz, Martin, Email: martin.schuetz@chemie.uniregensburg.de. Magnetizability and rotational g tensors for density fitted local secondorder MøllerPlesset perturbation theory using gaugeincluding atomic orbitals. United States. doi:10.1063/1.4884959.
Loibl, Stefan, and Schütz, Martin, Email: martin.schuetz@chemie.uniregensburg.de. Mon .
"Magnetizability and rotational g tensors for density fitted local secondorder MøllerPlesset perturbation theory using gaugeincluding atomic orbitals". United States.
doi:10.1063/1.4884959.
@article{osti_22308987,
title = {Magnetizability and rotational g tensors for density fitted local secondorder MøllerPlesset perturbation theory using gaugeincluding atomic orbitals},
author = {Loibl, Stefan and Schütz, Martin, Email: martin.schuetz@chemie.uniregensburg.de},
abstractNote = {In this paper, we present theory and implementation of an efficient program for calculating magnetizabilities and rotational g tensors of closedshell molecules at the level of local secondorder MøllerPlesset perturbation theory (MP2) using London orbitals. Density fitting is employed to factorize the electron repulsion integrals with ordinary Gaussians as fitting functions. The presented program for the calculation of magnetizabilities and rotational g tensors is based on a previous implementation of NMR shielding tensors reported by S. Loibl and M. Schütz [J. Chem. Phys. 137, 084107 (2012)]. Extensive test calculations show (i) that the errors introduced by density fitting are negligible, and (ii) that the errors of the local approximation are still rather small, although larger than for nuclear magnetic resonance (NMR) shielding tensors. Electron correlation effects for magnetizabilities are tiny for most of the molecules considered here. MP2 appears to overestimate the correlation contribution of magnetizabilities such that it does not constitute an improvement over HartreeFock (when comparing to higherorder methods like CCSD(T)). For rotational g tensors the situation is different and MP2 provides a significant improvement in accuracy over HartreeFock. The computational performance of the new program was tested for two extended systems, the larger comprising about 2200 basis functions. It turns out that a magnetizability (or rotational g tensor) calculation takes about 1.5 times longer than a corresponding NMR shielding tensor calculation.},
doi = {10.1063/1.4884959},
journal = {Journal of Chemical Physics},
number = 2,
volume = 141,
place = {United States},
year = {Mon Jul 14 00:00:00 EDT 2014},
month = {Mon Jul 14 00:00:00 EDT 2014}
}

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