Data Analysis Using Absorption Probability Density Example Guanidinium Nitroprusside

3 Data Analysis Using Absorption Probability Density (Example Guanidinium Nitroprusside) 

(CN3Hg)2[Fe(CN)5NO], may be considered as a calibration standard for NIS applications since nitroprusside complexes have been studied in detail over the past decades by a variety of experimental and theoretical methods. In addition, single crystals of GNP are well suited for the investigation of the anisotropy of molecular vibrations because the two nonequivalent NP anions, [Fe(CN)5NO] , in the unit cell of GNP have an almost antiparallel orientation. 

It should be noted that there are different preferences for the presentation of NIS spectra. In Fig. 9.35, the NIS pattern of hexacyanoferrate, (NH4)2Mg[Fe(CN)g], is given as partial DOS g E) [89], while in Fig. 9.36 for GNP, (CN3H5)2[Fe (CN)5N0], it is drawn as probability density S E) of nuclear inelastic absorption [86]. The projected probability density S(E,k) can be simulated theoretically if the projected PDOS g(E,k) is available. For molecular complexes, an approximation to simulate S(E,k) outside the energy range of intermolecular vibrations, i.e., for 15 meV, is given by [86]  

9 Nuclear Resonance Scattering Using Synchrotron Radiation 

The sum on the right side of (9.14) corresponds to g(E,k) in a single crystal. The PDOS g(E) for randomly oriented systems requires an averaging over all crystallographic directions. 

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