Hyperfine structure constant

The hyperfine structure constants of T1 6p[y2 Tl + which (like X and M) depend on operators concentrated near the T1 nucleus, were also calculated. The errors in the DF values are 10-15% with respect to experiment and the RCC-SD results are within 1-4% of experiment. The improvement in X and M upon inclusion of correlation is expected to be similar. 

Further information with respect to ZnS Mn nanocomposite phosphors is available from EPR spectra. The ZnS Mn/AA nanocrystal shows a typical sextet in X-band (9-GHz) ESR spectra, as shown by curve (a) in Figure 13.2.5. In contrast, the sample without AA exhibits the second component, signal II (Fig. 13.2.5b). From the sample with sulfur deficiency, ZnS(0.8) Mn, the relative intensity of signal II is higher (Fig. 13.2.5c). On the other hand, the g value, 2.0013, is significantly different from that of interstitial Mn(II) (g = 2.020) (19). From this, together with the value of the hyperfine structure constant (13), it is reasonable to assume that signal II is associated with Mn(II) with its coordination number lower than 3. 

Level crossing has been used rather widely in the case of atoms and ions in order to determine lifetime, Lande factors, fine and hyperfine structure constants and relaxation cross-sections of coherence (cri,a2). For deeper acquaintance with these questions we recommend monographs and reviews [6, 96, 228, 296, 300, 301, 314] and the literature cited therein. 

The hyperfine structure constant thus allows us to probe the electron distribution in radicals. Theoretically calculated values of the spin densities can then be compared with the experimental values obtained from Eq. (9). One of the simplest methods for calculating electron density in an aromatic hydrocarbon is to use Hiickel molecular orbital theory as discussed later. 

Figure 7. Fine structure constants D, hyperfine structure constants A, activation energies of the thermal reaction and singlet triplet energy separation of the dlradlcal and dlcarbene triplet states. There is a characteristic change of all properties when the structure changes from diradicals to dlcarbenes.

I participated as a graduate student in the experimental activities of the group but also given the task to learn about electronic structure calculations. The standard procedure for evaluation of nuclear moments from measured hyperfine structure constants was to obtain a value of r" from the spin-orbit coupling constant, using relativistic correction factors. The formulas as well as the relativistic correction factors were given in the book by Kopfermann... 

J. Bieron, I. P. Grant, C. FVoese Fischer, Multiconfiguration Dirac-Fock calculations of the hyperfine structure constants and determination of the nucleeir quadrupole moment of yttrium 90, Phys. Rev. A 58 (1998) 4401-4405. 

I. Khriplovich, P-odd difference of hyperfine structure constants in optical isomers, Z. Phys. A 322 (1985) 507-509. 

A number of stable l-aryl-3-phenyl-l,4-dihydro-l,2,4-benzotriazin-4-yl radicals have been registered by electron spin resonance (ESR) <1996AXC3124, 2002RCB1796>. In particular, the H and hyperfine structure constants for the stable l-(4-nitrophenyl)-3-phenyl-l,4-dihydro-l,2,4-benzotriazin -yl free radical, obtained by the oxidation of 1-(4-nitrophenyl)-3-phenyl-l,4-dihydro-l,2,4-benzotriazine, were determined by ESR and H electron nuclear double... 

Hyperfine splitting due to the ip nucleus was measured for six resonances, while hf splitting due to the D nucleus was not resolved. The analysis yielded precise values for the rotational, fine-structure, and hyperfine-structure constants of PD(X v = 0 and 1) (see pp. 11, 12, 15) and the band origin Vq(1 0)=1653.2858(36) cm" (three standard deviation) [6]. 

Here s denotes the spin of the single unpaired valence electron, i is the nuclear spin, Chf is the hyperfine-structure constant, ge and gn are the electronic and nuclear gyro-magnetic factors, respectively, and p,B is the Bohr magneton. The sign convention for gn used in Equation 11.1 follows Ref. [27]. 

In a second experiment,ENDOR measurements were performed in the optically populated excited p5/2> Es/2 state of Tm " in Cap2, using the same apparatus. The ENDOR transitions were monitored via the circular polarization of the fluorescence. The authors obtained the ligand hyperfine structure constants A, = 4.83 (3) MHz and Ap = 3.59 (3) MHz of the first shell of fluorine neighbors, thus providing the first ENDOR results of an optically excited state of an impurity center. 

The restricted delocalization of the p electron is essentially due to the energy difference of 2e = 0.4 eV per unit cell between the butatriene and acetylene chain structure. The chain length dependencies of the fine structure and hyperfine structure constants of the ESR spectra as well as the chain length dependencies of the absorption series have been described by theoretical model calculations. The complexity of the polymerzation reaction in diacetylene crystals has been demonstrated by the manifold of different reaction products observed in the experiments. The large amount of detailed information concerning the electronic structures and concerning the reaction mechanisms is essentially due to the crystalline structure of this model system and to the thermal stability of the reaction intermediates at low temperatures. 

Level-crossing signals at certain magnetic fields can be used for determining hyperfine structure constants of excited states. Why is the number of detectable signals quite limited Describe in general terms how hyperfine-structure information can be deduced from the experimental data. 

J. Carlsson, P. Jdiisson, L. Sturesson, C. Proese Fischer Multi-configuration Hartree-Fock calculations and time-resolved laser spectroscopy studies of hyperfine structure constants in sodium. Phys. Scr. 46, 394 (1992)... 

The rotational, vibrational, fine-structure, and hyperfine-structure constants for the NH ion, derived from the high-resolution IR autodetachment spectra, are given above the electron affinity of the NH molecule is given on p. 38. 

Kobayashi T, Endo I, Fukumi Aetal (1997) Measurement of hyperfine structure constants, g values and tensor polarizability of excited states of Sm I. Zeitschrift fiir Physik D 39 209-216. 

The nuclear spin I = 1/2 of Pt has been determined in 1936 by Jaeckel [21] who has derived the hyperfine structure constants A of 27 levels from the hfs of 46 Pt I lines in the region 5479 to 2357 A. Tolansky and Lee [22] have confirmed most of Jaeckel s measurements and derived the A factors of 7 other levels from lines between 6760 and 4327 A. 

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