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organic compounds
Thiosemicarbazid-1-ium dihydrogenphosphate, CH6N3S+.H2PO4-, unlike the semicarbazide complex compounds, does not exhibit temperature-dependent ferroelectric properties. X-ray structure determination at room temperature has shown that the crystal is centrosymmetric, space group C2/c, and thermal mobility of the structural units is relatively low. This allowed the refinement of all H-atom parameters without any space constraints. The H2PO4- anions, with a distorted tetrahedral configuration, are hydrogen bonded to the thiosemicarbazidium cations. The average observed Uiso value for the H atoms (0.045 Å2) suggests that the protons are well fixed at their sites, and the extensive three-dimensional system of moderately short hydrogen bonds forms a structure in which dynamic disorder by hydrogen `jumping' is not pronounced.