Lithium boro-hydride LiBH<sub>4</sub> : I. Crystal structure

Article Article scientifique Article Lithium boro-hydride LiBH<sub>4</sub> : I. Crystal structure eng 2002 author Soulie Jean-Philippe 543247 author Renaudin Guillaume 514209 author Cerny Radovan 28214 author Yvon Klaus 25146 200-205 10.1016/S0925-8388(02)00521-2 0925-8388 http://linkinghub.elsevier.com/retrieve/pii/S0925838802005212 The crystal structure of LiBH4 has been studied by synchrotron X-ray powder diffraction at room temperature and at 408 K. At room temperature it has orthorhombic symmetry [space group Pnma, a=7.17858(4), b=4.43686(2), c=6.80321(4) Å]. The tetrahedral (BH4)− anions (point symmetry m) are aligned along two orthogonal directions and are strongly distorted with respect to bond lengths [B–H=1.04(2)–1.28(1) Å] and bond angles [H–B–H=85.1(9)°–120.1(9)°]. As the temperature is increased the structure undergoes a first-order transition and becomes hexagonal (space group P63mc, a=4.27631(5), c=6.94844(8) Å at T=408 K). The (BH4)− tetrahedra align along c, become more symmetric [point symmetry 3m, B–H=1.27(2)–1.29(2) Å, H–B–H=106.4(2)°–112.4(9)°] and show displacement amplitudes that are consistent with dynamical disorder about their trigonal axis Hydrogen storage materials Metal hydrides Crystal structure Phase transition X-ray diffraction Dewey 500.2 33 Département de physique de la matière quantique 131 false 806 Groupe Cerny Journal of alloys and compounds 346 1-2 4ba78994-0dd5-42ea-abc1-96638792a9e1 Article (Published version) Restricted Cerny80.pdf 686386 application/pdf restrictedAccess Faculté des sciences / Section de physique / Département de physique de la matière quantique

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Lithium boro-hydride LiBH₄ : I. Crystal structure	Journal of alloys and compounds			2002	591	0

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Soulie, Jean-Philippe