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We present experimental Raman scattering results on single-crystal silicon monoarsenide (SiAs). Based on a comparison between Raman measurements and first-principles density functional theory calculations, we found evidence that SiAs will occur in a monoclinic crystal structure rather than an orthorhombic one as has been discussed in the literature. Further, we provide a detailed discussion of the vibrational properties of the monoclinic structure

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The generation of hydrogen as a chemical energy storage for power generation via fuel cells or for the synthesis of fuels has attained a strong interest in recent years. By way of example this is realized using electrolysis of water with the help of excess electricity of wind power plants. However with low temperature grade waste heat as it could be found in many industrial and household applications, there is another source of usable energy for this purpose. In a first pragmatic experimentation we investigated the pyroelectric effect of ferroelectric BaTiO3 combined with a temperature cycling to generate hydrogen from water. Therefore, single crystals ground to powder were brought into contact with distilled water and set to a cyclical temperature change from 40 °C to 70 °C. With the help of a highly selective and sensitive measuring system based on a coulometric solid electrolyte detector we could provide a first indication of pyroelectric generated hydrogen by a fraction of 300 Vol.-ppb in the sample gas.