Inelastic neutron scattering experiments

Highly energetic compounds with potential use in explosive devices must be characterized completely and safely, particularly as the explosive character may be linked directly to vibrational modes in the molecular structure, hence the application of computational methods to complement experimental observations. ANTA 5 has been the subject of various studies and, as an adjunct to one of these and to confirm the results of an inelastic neutron scattering experiment, an isolated molecule calculation was carried out using the 6-311G basis set <2005CPL(403)329>. 

The usefulness of potential energy hypersurfaces in describing reaction dynamics and chemical reactivity is well illustrated by Levine and Bernstein [84] and Shaik et al. [85] books. See also the fundamental paper of Hase [86]. This success does not assure that the coordinate representation of quantum system is necessarily truthful. It goes without saying, the coordinate representation is an extremely useful mathematical model. However, from recent inelastic neutron scattering experiments on hydrogen bonded system, the idea that the BO approximation may be inadequate has been advanced by Kearley and coworkers[87]. 

Because there is no general microscopic theory of liquids, the analysis of inelastic neutron scattering experiments must proceed on the basis of model calculations. Recently1 we have derived a simple interpolation model for single particle motions in simple liquids. This derivation, which was based on the correlation function formalism, depends on dispersion relation and sum rule arguments and the assumption of simple exponential decay for the damping function. According to the model, the linear response in the displacement, yft), satisfies the equation... 

Inelastic neutron scattering experiments have been used to study the ground state splitting of singly bridged dichromium(III) complexes of... 

A. Early experiments. The first inelastic neutron scattering experiments were performed about 15 years ago. This work... 

Inelastic neutron scattering, on the other hand, usually employs a monochromatic neutron beam and records the intensity of the scattered neutron beam as a function of neutron kinetic energy. Such inelastic collision spectra are monitored as a function of the applied field and the (usually low) temperature. The observed peaks then represent the energy differences of thermally populated and excited unpopulated multiplet states. Inelastic neutron scattering experiments can be conducted using triple-axis, backscattering, or time-of-flight spectrometers. 

C. K. Loong et ai, High-Energy Oxygen Phonon Modes and Superconductivity in Bai j,Kj,Bi03 An Inelastic-Neutron-Scattering Experiment and Molecular-Dynamics Simulation, Phys. Rev. Lett. 62, 2628-2631 (1989). 

The results of two inelastic neutron scattering experiments on U2Zn17 are rather controversial (Walter et al. 1987, Broholm et al. 1987a). Common features shared by both works are the absence of spin-wave excitations and the presence of a broad Lorentzian quasi-elastic line with T of the order of 10 meV, persisting across Tn. 

Inelastic neutron scattering experiments performed at 10 K displayed only a relatively broad quasi-elastic Lorentzian line with HWHM = (13 2) meV (Goldman et al. 1986a). Some indications of antiferromagnetic correlations were found by Neumann et al. (1986) up to 100 K. 

Rahman and Stillinger (1971) have applied to the study of liquid water a model potential, named ST2, which could anticipate the existence of the so called high frequency sound years before this collective excitation of water molecules was observed, by means of inelastic neutron scattering experiments (Texeira, Bellisent-Funel, Chen and Domer,(1985). Lie and dementi (1986) obtained a notable model potential for water from extensive ab initio calculations. 

Inelastic neutron scattering is a technique that has been widely used both in the liquid and in the solid states to measure the stmcture and dynamics at small (that is, molecular) length scales. In an incoherent inelastic neutron-scattering experiment, the measured quantity is the self-dynamic structure factor Ss(Q, (o), which gives information, as in the liquid state, of the self-diSiision coefficient of the water molecules. Ss(Q, (o) is the Fourier transform of the intermediate self-scattering function Fg(Q, t), which is defined by... 

Smith, J. Protein dynamics Comparison of simulations with inelastic neutron scattering experiments. Q. Rev. Biophys. 1991, 24 (3), 227-291. 

Two well-defined crystal-field excitations at 12.2 and 18.1 meV and a quasi-elastic excitation centered at zero energy were derived from inelastic neutron scattering experiments of ferromagnetic YbNiSn. A crystal-field potential based on a superposition model was presented in that work (Adroja et al. 1998). 

The crystal field (CF) level scheme of YbPd2ln and HoPd2ln has been determined by inelastic neutron scattering experiments (Babateen et al., 1995) W = 0.02673 X = 0.3543 for HoPd2ln and W = -0.5194 X = -0.7485 for YbPd2ln. For the magnetization curves, satisfactory agreement is observed for the calculated and measured data. 

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