Computation of conventional NMR parameters has become routine. There remain, however, interesting physics to be explored. I introduce four topics of this kind.
For the first time, measured $J$-coupling over a van der Waals (vdW) bond, between 129Xe and 3He in a gas-phase nuclear spin co-magnetometer, can be directly compared with quantitative calculations . The latter involve the second virial coefficient of $J$(129Xe-3He) from relativistic potential energy and $J$-coupling curves.
NMR parameters are magnetic field-dependent. So far, only $B$0-dependent 131Xe quadrupole coupling has been found . Experiments on Co(acac)3 -complex , where low-lying d-d excitations render the 59Co shift significantly $B$0-dependent, are compared with non-linear response theory for the leading $O$($B$02) terms .
Nucleus-specific information can be obtained from changes in light beam polarisation due to interaction with nuclear spins . We predict nuclear spin-induced magnetochiral birefringence and dichroism, as possible reporters of chirality via different indices of refraction when light propagates parallel and antiparallel with spin magnetisation .
In a multi-scale study of spin-exchange optical pumping , Rb-Xe collisions are extracted from molecular dynamics and analysed using spin dynamics driven by a quantum-chemical spin Hamiltonian. We reproduce the roles of binary collisions and long-lived vdW complexes and, for the first time, see step-wise build-up of 129Xe polarisation upon vdW oscillations.
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