Electronic susceptibility

The n-electron excitations are viewed as occuring on molecular sites weakly coupled to their neigbors and providing sources of nonlinear optical response through the on-site microscopic second order nonlinear electronic susceptibility... 

NMR line is proportional to the local electronic susceptibility, and in such a situation, it will be very different for the different sites. For a Cs neighboring a C d, the local electronic susceptibility is dominated by the excitations of the singlet, leading to a strong temperature dependence for the S line clearly seen in Fig. 10. On the contrary, the NS line does not shift, according to the temperature-independent susceptibility characteristic of a metal. A similar contrast is found in the spin-lattice relaxation rate 1/T, for each line. The relatively small number of singlets explains that macroscopic probes, such as ESR, only detect the predominantly metallic character. 

NMR provides a different and far superior means to measure M0 by tipping M away from the 2 axis into the xy plane, where it precesses at the Larmor frequency and can be selectively detected without interference from the static electron susceptibility. We can examine this process in classical terms. 

The room-temperature electronic susceptibility is typically 3 x 10 4 emu cm3 mol-1 for (TMTSF)2X compounds and decreases approximately linearly with decreasing temperature until the transition occurs (93-95). Below the transition there is a clear distinction between the three possible ground states discussed above (61, 94). This... 

A cyclic molecule is strobilic when it contains a distribution of delocalized Tt electrons susceptible, in the absence of substantial gradient of localized (a+ir) charges on the atoms of the ring, to be set in ordered movement when submitted to a magnetic field, thus giving rise to a strobilic Pauling-Pople current. 

This field has expanded very rapidly in just the last two years with the development of many new experimental techniques. The excitement continues. The nature of these new experimental probes has and will continue to significantly influence the development of the field. The ability to select a specific size cluster ion and study its properties is an important new tool. Photoelectron spectroscopy will provide new insight about the electronic structure of clusters as a function of cluster size. Magnetic deflection and electronic susceptibility experiments on neutral clusters and cluster adducts will also provide important information. Vibrational spectroscopy using a variety of different... 

Its first use is perhaps the simulation of electronic dynamics like atoms and molecules in strong electric fields for example [211-214]. This is also an approach to electronic spectroscopy, calculating the electronic response to applied time-dependent potentials. The time-dependant electronic susceptibility is indeed the time-dependent reponse to a Dirac like perturbation. 

On the basis of ab initio calculations of the electronic structure and electronic susceptibility, the relations between the nesting properties of the Fermi surface and the features of commensurate long-period nanostructures in alloys have been studied. 

The nonlinear optical response of these materials in four wave mixing experiments is dominated by trans-cis isomerization. This isomerisation goes through a two photon process. The measured (underestimated) value of X (-u u,-u, ) at 1.064 is about one order of magnitude larger than the electronic susceptibility x (-3w w,w,w), as determined by THG technique. 

Here xo(q) is the conduction electron susceptibility, /(q) may be fitted to the experimentally observed magnetic excitations. 

Infig. 39 anotherimportant feature is obvious As temperature is lowered below Tc = 1.8K the quasielastic peak evolves into a low energy inelastic peak. This is due to the appearance of the SC quasiparticle gap function A(k) which possibly may have node lines or points. Its influence on the conduction electron susceptibility may be described in a simple manner by shifting the diftusive pole at -iP in x (< ) to -iP Aav where the real part corresponds... 

Roeland et al. investigated the conduction electron susceptibility ce from a study of the high-field susceptibility, considering a phenomenological expression for the relation between the ionic and conduction electron magnetization of the form... 

X (T = 0) is apparently considerably enhanced above the Pauli susceptibility Ap = 2(gMB)V( p) = 2.4 X 10 p.bT calculated from Keeton and Loucks (1968) estimate of the density of states at the Fermi level. However, a note of caution needs to be injected into these estimates of the conduction electron susceptibility. It is apparent from figs. 6.1 and 6.2 that some 10 to 15 T are required to complete the magnetization process by overcoming residusd domain walls and the effects of crystal imperfections. Measurements of the high-field susceptibility... 

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