Molecular magnetic properties within continuous transformations of origin of the current density

Abstract

Articles you may be interested inNon-perturbative calculation of molecular magnetic properties within current-density functional theory Gauge invariant calculations of nuclear magnetic shielding constants using the continuous transformation of the origin of the current density approach. II. Density functional and coupled cluster theory J. Chem. Phys. 126, 154111 (2007); 10.1063/1.2721536Correlated and gauge invariant calculations of nuclear magnetic shielding constants using the continuous transformation of the origin of the current density approach Calculation of third-rank molecular hypermagnetizabilities by continuous transformation of the origin of the current density Coupled Hartree-Fock calculations of molecular magnetic properties annihilating the transverse paramagnetic current density A new method for the calculation of molecular magnetic susceptibility and nuclear magnetic shielding is presented. It is based on continuous transformations of origin of the current density which make the transverse part of the paramagnetic current vanish. For any molecule all the components of the nuclear magnetic shielding tensor provided by the new method are independent on the origin of the gauge, whereas the components of the magnetizability tensor are translationally invariant only for center-symmetric molecules ͑they, in general, show a linear dependence on the shift of origin͒. This method, termed CTOCD-PZ, has been implemented for the theoretical determination of molecular magnetic properties via numerical integration techniques and, from preliminar results obtained for methane and carbon dioxide molecules, reveals reliable.

High sensitivity of O17 NMR to p-d hybridization in transition metal perovskites: First principles calculations of large anisotropic chemical shielding

“…The apparent dependence of the chemical shielding on the band gap can be somewhat misleading, however, since the transverse paramagnetic component of the first order current density could be made to vanish under suitable gauge transformations within the CSGT gauge method. 42,67 The entire shielding would then be given by the diamagnetic component, which depends only on the occupied single particle states. Similar observations were made regarding calculations of the the spontaneous polarization P and Z * in ferroelectric perovskites, where RHF results for these quantities were found to be in good numerical agreement with both experiment and with DFT calculations, 68,69 both methods yielding anomalously large Z * .…”

Efficient mapping of ring currents in fullerenes and other curved carbon networks

“…Then, the map of the current density induced in the H N -system by a perpendicular magnetic field is calculated self-consistently and ipsocentrically, i.e. with the full coupled HartreeFock CTOCD-DZ (continuous transformation of origin of current density-diamagnetic zero) approach [30]. The first stage rests on the one-to-one correspondence between the Hückel molecular orbitals of a π system and the σ orbitals of an array of hydrogen atoms with the same connectivity.…”

“…Such currents can be inferred indirectly from their effects on observable magnetic properties (exaltation of magnetisability [17][18][19], downfield chemical shifts of external hydrogen nuclei [20]) and properties that are sub-observables, in Hirschfelder's sense [21], such as the characteristically negative NICS value at the ring centre or some other chosen point [22]. Inferences of this type all have difficulties associated with masking of ring-current effects by other contributions to the property [23][24][25][26][27], but ring-current aromaticity can in fact be deduced directly from calculation of the induced current itself, by solution of the Schrödinger equation for the molecule immersed in the magnetic field, using an appropriate distributed-origin method [28][29][30][31]. The present paper is concerned with the application of this technique to fullerenes and similar curved-carbon molecules.…”

Current density maps, magnetizability, and nuclear magnetic shielding tensors of bis-heteropentalenes. II. Furo-furan Isomers

“…The gauge invariant results obtained via the London orbitals, indicated by LO in Table II, are partitioned into diamagnetic, d , and paramagnetic, p , contributions, evaluated with respect to the center of mass. The notation adopted for the various CTOCD estimates [15][16][17][21][22][23][24] is the same as in paper I of this series. 6 The least symmetric molecule, furo͓3,4-b͔furan, has been studied only via the GIAO approach of the DALTON package.…”