Nuclear Spin-Rotation Interaction Constants

A complete set of magnetic hf coupling constants and the P nuclear spin-rotation interaction constants (all in MHz) were obtained from an analysis of the hf structure of twelve lH(total H nuclear spin) = 0 and fourteen Ih=1 rovibronic lines of the A (0, 0, 0) X (0, 0, 0) band. An Intermodulated fluorescence (IMF) method was applied, which was first shown in [17] to be able to eliminate the Doppler width. A dye laser was employed as a source. Ground state constants were taken from a preliminary publication of [3] (T c was obtained with the sum rule) [6] ... 

Absolute Shielding Scales. - Gee and Wasylishen have recommended that the microwave study of AlH be repeated, as the previous one failed to account for the Al nuclear spin-rotation interaction. Their ab initio calculations give a range of values depending on the method used but are all of the order of 300 kHz. The value of the spin-rotation constant for Al in AIF, on the other hand, has been measured, Cj = 8.2 1.3 kHz, which leads to (ct — CTj ) = 320 50 ppm for Al in AIF and... 

A detailed investigation of the nuclear spin-lattice relation time, T l. in liquid [Ni(CO)J and [Fe(CO)s] as a function of temperature and resonance frequency has been carried out 212). It was concluded that relaxation occurs only by two mechanisms, i.e., spin-rotation interaction and anisotropic chemical shift. It was possible to obtain the anisotropic chemical shift difference of 440 ppm for [Ni(CO)4] and 408 ppm for [Fe(CO)s] and the spin-rotation constants. Apparent activation energies for diffusion of 1.0 kcal/mole for [Ni(CO)4] and 2.9 kcal/mole for [Fe(CO)5] were derived. 

Nuclear Quadrupole Coupling Constants, Nuclear Spin-Rotation Constants, Nuclear Spin-Spin Interaction Constants... 

The Hyperfine Tab (Fig. 15) is only valid if the atom containing one or more unpaired electrons (the electron spin is greater than zero) has isotopes wifli a nonzero nuclear spin. The interaction can be turned ofEon with a middle mouse click on the red/blue tick on the hyperfine tab. Identical representations (isotropic, axial, and orthorhombic) to those for the electron Zeeman interaction are available for the hyperfine interaction. The hyperfine coupling constants correspond to the isotope of the particular atom that has the largest isotopic abundance. For randomly orientated solutions, molecules containing a single unpaired electron with monoclinic or triclinic symmetries, the Euler angles, a, P, and y will be nonzero, a corresponds to a rotation about the z (gP axis, p a rotation about the new axis, and y a rotation about the new axis. 

Ajo = spin-orbit interaction constant Ay By, Cy = rotational constants of radical a, b = hyperfine constants 5= external magnetic field d= difference of relative populations Dy = centrifugal constant for diatomic molecule Dy, Ey= parameters of Hamiltonian H33 E = electric field of laser radiation f = modulation frequency gj, gj = electron and nuclear g-factors g, gi, g = spin, orbital and rotational g-factors h = Planck s constant = Watson s... 

ROSSNER et al. [10.27d] measured the very small hfs splitting (<100 kHz) of a rovibronic level (v" = 0, J" = 28) in the X ground state of the Na2 molecule. This splitting is much smaller than the natural linewidth of the optical transitions. The quadrupole coupling constant was determined to e q Q = 463.7 0.9 kHz and the nuclear spin-molecular rotation interaction constant came out to be a = 0.17 0.03 kHz. 

The first line in this expression describes the rotational structure with color spin-doubling and the hyperflne interaction of the effective electron spin S with the nuclear spin I. B is the rotational constant, J is the electron-rotational angular momentum, A is the o -doubling constant. The second line describes the interaction of the molecule with the external fields B and E, (A is the unit vector directed from the heavy nucleus to the light one). The last line corresponds to the P-odd electromagnetic interaction of the electrons with the anapole moment of the nucleus described by the constant /ca [40], P,T-odd interaction of the electron EDM de with the interamolecular field, and P,T-odd scalar interactions of the electrons with the heavy nucleus [90]. 

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