EPR Interactions - Nuclear Quadrupole Couplings

ELDOR-detected NMR beyond hyperfine couplings: a case study with Cu(ii)-porphyrin dimers

“…A i denotes the hyperfine coupling between electron i and nucleus i. The last term in parentheses is the nuclear quadrupole interaction, which is given in its principal axis system by 44 P ¼…”

Metallofullerene photoswitches driven by photoinduced fullerene-to-metal electron transfer

“…94 The zero-field splitting term in the principal frame transforms to: Ĥ ZFS = Ŝ T D Ŝ = D [ Ŝ z 2 − S ( S + 1)/3] + E ( Ŝ x 2 − Ŝ y 2 ) with D and E defined through the principal values of D as D = 3/2 D z , and E = ( D x − D y )/2. The electric nuclear quadrupole term for each quadrupolar nucleus can be written as in eqn (4) : 95 Ĥ NQI = Î T P Î = K [3 Î z 2 − I ( I + 1) + η ( Î x 2 − Î y 2 )] with where P x , P y , and P z are the diagonal elements of P , q is the electric field gradient along the principal axis ( z -axis) of the largest field gradient, Q is the nuclear quadrupole moment. The factor e 2 qQ / h is usually denoted as the quadrupolar coupling constant in MHz.…”

Regularized dynamical decoupling noise spectroscopy – a decoherence descriptor for radicals in glassy matrices

“…For the deuterated nitroxide, the nuclear quadrupole coupling P i contributes, while we neglect the small asymmetry typical for C–D bonds. 40 Cyclic permutation of index i (I → II → III) generates the spin Hamiltonians for φ = 120° and −120°. Using the Easyspin 41 function sphgrid, we average over the orientation-dependence of the HF couplings A i = (3 cos 2 θ − 1) a i and B i = 3cos θ sin θa i as well as the NQ coupling P i = (3 cos 2 ϕ − 1) K with , where θ and ϕ are the angles between the electron-nuclear spin vector and the C–D bond with the magnetic field direction, respectively.…”