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The crystalline structure of the starch of six cultivars of rice for sake brewing were studied by small-/wide-angle X-ray scattering and X-ray diffraction by synchrotron radiation. The starch structures all provide a lamella structure of a crystal phase and an amorphous phase. The crystal phases of the starches show A-type starch and some B-type starch. The B-type starch content varied slightly between the different rice cultivars, with Yamadanishiki-type containing the most. The change in starch structure upon the early stage of sake brewing was also investigated. The crystal structure and lamella structure were maintained after soaking in water. However, the structure of starch changed to an amorphous phase upon steaming and gelatinization. While the steamed rice was cooled at 15 °C, the starch crystal structure, but not lamella structure, was recovered. Furthermore, the dependence of B-type starch content on the cultivars was also recovered. This result indicated that the crystals of starch destroyed imperfectly, but also crystalline nuclei remained after steaming.

A powder diffraction measurement system constructed on a beam-line BL5S2 at Aichi Synchrotron Radiation Center in Seto, Japan, has been modified for extensive use of two-dimensional (2D) X-ray detectors. Four flat 2D detectors are currently mounted on the movable stages on supporting rods radially attached to the 2Θ-wheel of the goniometer with the interval of 25°. The 2D powder diffraction intensity data are reduced to conventional 1D format of powder diffraction data by the method based on averaging of the pixel intensities with geometrical corrections, which also enables evaluation of standard uncertainties about the reduced intensity data. The 1D powder diffraction data of a 0.1 mm-capillary LaB6 (NIST SRM660b) sample obtained at the camera length of 340 mm have shown almost symmetric peak profile with slight asymmetry simulated by a beta-distribution profile function.

Dehydrogenation properties and crystal structure of the double anion complex hydride Mg(BH4)(NH2) were studied by thermal analyses and synchrotron X-ray diffraction. The stoichiometric mixture of Mg(BH4)2 and Mg(NH2)2 were ball-milled and then heated to 453 K to form Mg(BH4)(NH2) crystal. The dehydrogenation of Mg(BH4)(NH2) occurs in two-stage at 513 K and 688 K. The following reaction sequence is suggested by the results of thermal analyses; Mg(BH4)(NH2) → MgH2 + BN + 2H2 (7.3 mass% weight loss) → Mg + BN + 3H2 (11.0 mass% weight loss in total). The dehydrogenation temperature of Mg(BH4)(NH2) is approximately 50 K lower than that of the other double anion complex Li2(BH4)(NH2). The crystal structure of Mg(BH4)(NH2) was determined by the measurement at 300 K (crystal system: tetragonal, space group: I41 (No. 80), lattice constants: a = 5.792(1), c = 20.632(4) A at 300 K). In the crystal of Mg(BH4)(NH2), the cation (Mg2+) and the anions ( BH 4 - and NH 2 - ) are stacked alternately along the c-axis direction. The Mg2+ cation is tetrahedrally coordinated with two BH 4 - anions and two NH 2 - anions.

Complex hydride Mg(BH4)(NH2), which consists of double anion BH4− and NH2−, was synthesized and the crystal structure was analyzed by synchrotron X-ray diffraction. The mixture sample of Mg(BH4)2 + Mg(NH2)2 prepared by ball milling was reacted and crystallized to Mg(BH4)(NH2) by heating at about 453 K. This crystal phase transforms into amorphous phase above 473 K and subsequently the dehydrogenation begins. The crystal structure of Mg(BH4)(NH2) was determined from measurement data at 453 K (chemical formula: Mg0.94(BH4)1(NH2)0.88, crystal system: tetragonal, space group: I41 (No.80), Z = 8, lattice constants: a = 5.814(1), c = 20.450(4) A at 453 K). Mg(BH4)(NH2) is ionic crystal which the cation (Mg2+) and the anions (BH4− and NH2−) are stacking alternately along the c-axis direction. Two BH4− and two NH2− tetrahedrally coordinate around Mg2+ ion.

Intermediate compound comprising [B12H12]2– anion formed in the dehydrogenation is regarded to be responsible for the degradation of reversibility of metal borohydrides, whereas little is known about the formation of Li2B12H12 in the LiBH4–MgH2 combined system. In this study, we investigated the dehydrogenation process of the LiBH4–MgH2 system in a heating run under different hydrogen pressures. Our experimental results demonstrated, for the first time, that Li2B12H12 was formed under hydrogen pressure ≤1.0 MPa, but not formed under 2.0 MPa. Moreover, the formation of Li2B12H12 was found to negatively depending on the hydrogen pressure, and also influence subsequent formation of MgB2: the more Li2B12H12 that formed, the less MgB2 obtained. These findings indicate that suppression of the formation of intermediate compound Li2B12H12, such as by using adequate hydrogen pressures (e.g., 2.0 MPa), is of great importance for further improvement of hydrogen storage properties of the LiBH4–MgH2 system.

The existence of Mg(B12H12) as an intermediate compound during the dehydrogenation process of Mg(BH4)2 has been verified. To elucidate the formation process of Mg(B12H12), the dehydrogenation products of Mg(BH4)2 at different temperatures were characterized via Xray diffraction and B magic angle spinning NMR measurements. The experimental results indicate that several new intermediate compounds such as Mg(B2H6) and Mg(B5H9) or Mg(B5H8)2 are expected to be formed prior to the formation of Mg(B12H12). Thus, it is suggested that the formation of [B12H12] 2 from [BH4] occurs via the gradual evolution of the B-H complex anion, i.e., [BH4] ! [B2H6] ! [B5H9] or [B5H8] ! [B12H12] . [doi:10.2320/matertrans.MA201002]

Calcium borohydride Ca(BH4)2 is one of the promising new hydrogen storage materials because of its large amount of hydrogen desorption capability (9.6 mass%). The crystal structures of α-Ca(BH4)2 (space group: Fddd, lattice constants: a = 8.7782(2) A, b = 13.129(1) A, c = 7.4887(9) A) and β-Ca(BH4)2 (P42/m, a = 6.9509(5) A, c = 4.3688(3) A) were refined by synchrotron X-ray diffraction at 300 and 433 K, respectively. The unsolved structures of γ-Ca(BH4)2 (Pbca, a = 7.525(1) A, b = 13.109(2) A, c = 8.403(1) A) and Ca(BH4)2·H2O (Pnma, a = 8.200(1) A, b = 5.8366(7) A, c = 11.851(2) A) were determined. In α-, β- and γ-Ca(BH4)2 structures, six boron atoms around a calcium atom construct CaB6 octahedron. The polymorphism of Ca(BH4)2 is formed by the different connection with adjacent octahedrons sharing vertexes and edges of the CaB6 octahedron. Furthermore, the charge density distribution in α-Ca(BH4)2 was experimentally determined by maximum entropy method. It is clarified that the bonding nature in α-Ca(BH4)2 ionic crystal is constructed from Ca2+ cation and BH4− anion.

Y(BH4)3 was prepared by liquid-phase synthesis, and its dehydriding and rehydriding properties were systematically investigated by performing thermogravimetry and differential thermal analysis (TG-DTA) and powder X-ray diffraction (XRD) measurement. The dehydriding reaction of Y(BH4)3 starts at appropriately 460 K, and a total of 7.8 wt% of hydrogen is released up to 773 K. Phase transformation and melting are observed in Y(BH4)3 at approximately 474 K and 499 K, respectively. Both DTA and XRD measurement results indicate that the decomposition of Y(BH4)3 proceeds via multistep dehydriding reactions accompanied with the formation of an intermediate phase. Furthermore, Y(BH4)3 is proved to be partially rehydrided.

In this study, a single phase Mg(BH4)2 was chemically synthesized by means of the metathesis reaction of MgCl2 with NaBH4 in diethyl ether, and its hydrogen storage properties on dehydriding and rehydriding reactions were also investigated. These results provide valuable insights for hydrogen storage technologies. 2. Experimental The starting materials, anhydrous MgCl2 (95% purity) and NaBH4 (99.99% purity), were purchased from Aldrich Co., Ltd. The organic solvent of diethyl ether (dehydrated, CicaReagent) was purchased from Kanto Chemical Co., Inc. Mg(BH4)2 was synthesized by means of the metathesis reaction of MgCl2 with NaBH4 according to the following reaction. 28–30)

Metal-borohydrides M(BH4)n (M ¼ Mg, Sc, Zr, Ti, and Zn; n ¼ 2{4) were synthesized by mechanical milling process according to the following reaction; MCln þ nLiBH4/nNaBH4 ! M(BH4)n þ nLiCl/nNaCl. Then the thermal desorption properties of M(BH4)n were investigated by gas-chromatography and mass-spectroscopy combined with thermogravimetry. The results indicate that the hydrogen desorption

An effective method for developing amide-based high-performance hydrogen storage materials is to prepare appropriate combinations of amides and hydrides. We have proposed that a mixture of an amide with a low decomposition temperature and a hydride showing rapid reaction to ammonia would be an appropriate combination. According to this proposal, the mixture of Mg(NH2)2 (Mg amide) and LiH (Li hydride) was investigated. The dehydriding temperature of the mixture of Mg(NH2)2 and 4� LiH is lower than that of the mixture of LiNH2 (Li amide) and 2� LiH. A method for preventing ammonia release is increasing the LiH ratio in the mixtures, which results in a reduction in the amount of desorbed hydrogen. The homogeneous dispersion between Mg(NH2)2 and LiH might be also an important factor for preventing ammonia release.

Ni-MH電池で用いられるペースト式負極(集電体:金属板)の複素インピーダンス解析を行った。電池を解体することなく,電池内部の電解液抵抗,負極活物質問の接触抵抗,腐食生成物によるインピーダンス,電解液/活物質問の電荷移動抵抗と電気二重層容量ならびに活物質内の水素拡散の関係したWarburgインピーダンスに関する情報が得られた。また,電極の多孔性がペースト式電極のインピーダンスを解釈する上で非常に重要なことが明らかになった。

MgH2 is one of the promising base materials for hydrogen storage, which is a key technology of clean energy source. In this study, the bonding nature of hydrogen in MgH2 was fully uncovered by examining the charge density distribution of this substance obtained by the maximum entropy method from the synchrotron radiation powder data. MgH2 can be expressed as Mg1.91+ H0.26−, which is much weaker ionicity than the theoretical expectations. It also shows weak covalence between Mg and H. Though the bonding nature of hydrogen in MgH2 is rather complex, i.e., the mixture of ionic and covalent bonding, it is certain that hydrogen is weakly bonded to Mg, which must be a big advantage of hydrogenation–dehydrogenation of this substance.

Calcium borohydride Ca(BH4)2 is one of the promising new hydrogen storage materials because of its large amount of hydrogen desorption capability (9.6 mass%). The crystal structures of α-Ca(BH4)2 (space group: Fddd, lattice constants: a = 8.7782(2) A, b = 13.129(1) A, c = 7.4887(9) A) and β-Ca(BH4)2 (P42/m, a = 6.9509(5) A, c = 4.3688(3) A) were refined by synchrotron X-ray diffraction at 300 and 433 K, respectively. The unsolved structures of γ-Ca(BH4)2 (Pbca, a = 7.525(1) A, b = 13.109(2) A, c = 8.403(1) A) and Ca(BH4)2·H2O (Pnma, a = 8.200(1) A, b = 5.8366(7) A, c = 11.851(2) A) were determined. In α-, β- and γ-Ca(BH4)2 structures, six boron atoms around a calcium atom construct CaB6 octahedron. The polymorphism of Ca(BH4)2 is formed by the different connection with adjacent octahedrons sharing vertexes and edges of the CaB6 octahedron. Furthermore, the charge density distribution in α-Ca(BH4)2 was experimentally determined by maximum entropy method. It is clarified that the bonding nature in α-Ca(BH4)2 ionic crystal is constructed from Ca2+ cation and BH4− anion.

We have prepared pure $\mathrm{Ca}{(\mathrm{B}{\mathrm{H}}_{4})}_{2}$ without any solvent adducts and determined its structural parameters by powder x-ray diffraction measurement. The crystal structure of $\mathrm{Ca}{(\mathrm{B}{\mathrm{H}}_{4})}_{2}$ is found to be orthorhombic with space group $Fddd$ (No. 70). Using this structural information, the first-principles calculations have been performed to investigate the fundamental properties of $\mathrm{Ca}{(\mathrm{B}{\mathrm{H}}_{4})}_{2}$. The interaction between Ca atoms and $\mathrm{B}{\mathrm{H}}_{4}$ complexes has an ionic character while the internal bonding of $\mathrm{B}{\mathrm{H}}_{4}$ is essentially covalent. It is confirmed that $\mathrm{Ca}{(\mathrm{B}{\mathrm{H}}_{4})}_{2}$ obeys the linear relationship between the heat of formation and the Pauling electronegativity of the cation, which has been proposed in a previous study [Nakamori et al., Phys. Rev. B 74, 045126 (2006)].

Note: Times Cited: 110 Reference EPFL-ARTICLE-206017doi:10.1103/PhysRevB.74.075110View record in Web of Science URL: ://WOS:000240238800042 Record created on 2015-03-03, modified on 2017-05-12

Note: Times Cited: 251 Reference EPFL-ARTICLE-206012doi:10.1103/PhysRevB.74.045126View record in Web of Science URL: ://WOS:000239426800043 Record created on 2015-03-03, modified on 2017-05-12

Lithium hexahydridoaluminate Li(3)AlH(6) and lithium amide LiNH(2) with 1:2 molar ratio were mechanically milled, yielding a Li-Al-N-H system. LiNH(2) destabilized Li(3)AlH(6) during the dehydrogenation process of Li(3)AlH(6), because the dehydrogenation starting temperature of the Li-Al-N-H system was lower than that of Li(3)AlH(6). Temperature-programmed desorption scans of the Li-Al-N-H system indicated that a large amount of hydrogen (6.9 wt %) can be released between 370 and 773 K. After initial H(2) desorption, the H(2) absorption and the desorption capacities of the Li-Al-N-H system with a nano-Ni catalyst exhibited 3-4 wt % at 10-0.004 MPa and 473-573 K, while the capacities of the system without the catalyst were 1-2 wt %. The remarkably increased capacity was due to the fact that the kinetics was improved by addition of the nano-Ni catalyst.

The thermodynamical stability of ${\rm Al(BH_4)_3}$ has been investigated using first-principles calculations based on density functional theory. The heats of formation are obtained to be -132 and $-131 {\rm kJ/mol}$ without the zero-point energy corrections for $\alpha$- and $\beta$-${\rm Al(BH_4)_3}$, respectively, which are made up of discrete molecular ${\rm Al(BH_4)_3}$ units. It is predicted correctly that the $\alpha$ phase is more stable than the $\beta$ phase. The energy difference between the solid phases and the isolated molecule is only about 10 kJ/mol. An analysis of the electronic structure also suggests the weak interaction between ${\rm Al(BH_4)_3}$ molecules in the solid phases. It is confirmed that ${\rm Al(BH_4)_3}$ obeys the linear relationship between the heat of formation and the Pauling electronegativity of the cation, which has been proposed in our previous study [Nakamori {\it et al.}, Phys. Rev. B {\bf 74}, 045126 (2006)]., Comment: 5 pages, 5 figures, Proceedings of MH2006 (Maui, October 1-6, 2006)

Mg(NH2)2-LiH system which have the properties of reversible hydrogenation and dehydrogenation is one of the promising candidates for new hydrogen storage materials. For understanding of the reversible reaction mechanism, we investigated the crystal structure changes in 3Mg(NH2)2-12LiH system using the pressure-composition (p-c) isotherm measurement and synchrotron X-ray diffraction. The sample was prepared by the hydrogenation of Mg3N2 + 4Li3N. At the several dehydrogenation stages of the p-c isotherm measurement at temperature 523 K, the sample was taken out and X-ray diffraction measurement was performed. By the amount of desorbed hydrogen, the reaction was expressed as the following formula, Mg(NH2)2 + 4LiH → LixMg(NH2)2-x(NH)x + (4-x)LiH + xH2 (x = 0∼2). The crystal structures of LixMg(NH2)2-x(NH)x, similar to CaF2-type one, formed during the dehydrogenation reaction were determined by Rietveld analysis. As a result, it is considered that the dehydrogenation process might relate to the diffusion of Li+ ion in cation sites of Mg(NH2)2.

Recent investigations on thermodynamical stabilities of metal borohydrides were reviewed. The first-principles calculations indicated that the heat of formation normalized by the number of BH4 complexs, ΔHboro, show a good correlation with the Pauling electronegativitiese of M, χp, which is represented by the liner relation, ΔHboro = 252.8χp − 396.4 in the unit of kJ/mol BH4. In order to clarify the correlation between the stability of borohydrides and the electronegativity χp of M, M(BH4)n (M = Mg, Ca, Sc, Ti, V, Cr, Mn, Zn, Zr and Al; n = 2-4) were systematically synthesized by mechanical milling. The thermal desorption analyses indicated that Td correlate with χ p of M; Td decrease with increasing the values of χp, in M(BH4)n. Furthermore, the correlation can be reasonably extended to double cation ones, (ZrLin-4)(BH4)n. For single cation, M(BH4)n (M = Mn, Zn and Al; χp ≥ 1.5) desorb borane besides hydrogen, and M(BH4)n (M = Ti, V and Cr; χp ≥ 1.5) desorbe small amount of hydrogen provably due to desorption reaction during milling. Therefore χp is an indicator to approximately estimate the stability of M(BH4)n, and appropriateχp in M(BH4)n is expected to be smaller than 1.5. The enthalpy change for the desorption reaction, ΔHdes, is estimated using our predicted ΔHboro and the reported data for decomposition product, ΔHhyd/borideboro, which shows a good correlation with the observed Td. These results are useful for exploring M(BH4)n with appropriate stability for hydrogen storage applications

Hydrogen desorption reactions of the mixtures of (i) lithium amide and lithium hydride (LiNH2/LiH), and (ii) magnesium amide and lithium hydride (Mg(NH2)2/4LiH) were studied. Titanium compounds and nano-particles including fullerene (C60), were doped to those hydrogen storage mixtures respectively. The hydrogen desorption reactions were monitored by means of temperature programmed desorption (TPD) technique under an Ar atmosphere. The reaction of LiNH2/LiH was accelerated by adding either 1 mol% of Ti species or 0.2 mol% of fullerene (C60), while those additives did not show significant acceleration effects on the reaction of Mg(NH2)2/4LiH. Kinetic studies revealed the enhanced hydrogen desorption reaction rate constant for TiCl3 doped LiNH2/LiH, k = 3.1 × 10−4 s−1 at 493 K, and the prolonged ball-milling further improved reaction rate, k = 1.1 × 10−3 s−1 at the same temperature. For the dehydrogenation reaction of TiCl3 doped LiNH2/LiH, the activation energies estimated by Kissinger plot (95 kJ mol−1) and Arrhenius plot (110 kJ mol−1) were in reasonable agreement each other. The LiNH2/LiH mixture without additive exhibited slower hydrogen desorption process and the kinetic traces deviated from single exponential behavior. The results indicated the Ti(III) additives change the hydrogen desorption reaction mechanism of LiNH2/LiH.

In order to clarify the reason why the hydrogen desorption temperature (Td) of MgH2 is lowered by milling, we have studied the change in a local nuclear magnetic field with temperature by means of μ+SR. We have found a very clear oscillation in the ZF-spectrum at 2 K for the "milled" and "milled with Nb2O5" samples, while such oscillation is weaker for the "as prepared" MgH2. It was also found that the oscillation signal is stable up to 250 K and is assigned mainly due to the formation of a H-μ-H system. At temperatures above ambient T, we also found that the ZF-μ+SR spectrum exhibits a static Kubo-Toyabe behavior due to the nuclear magnetic field of 1H. Furthermore, it was clarified that rapid H diffusion starts well below Td only in the milled samples, leading to the conclusion that the consequent enhanced diffusion rate in MgH2 is essential to accelerate the desorption reaction and to decrease Td.

The fundamental properties of lithium amide $\mathrm{Li}\mathrm{N}{\mathrm{H}}_{2}$, which is fully hydrogenated phase of lithium nitride ${\mathrm{Li}}_{3}\mathrm{N}$, have been investigated by the first-principles calculations using the ultrasoft pseudopotential method, including the structural, electronic, dielectric, and vibrational properties. The calculated structural parameters agree well with the experimental data except for hydrogen positions. The analyses for the electronic structure and the Born effective charge tensors indicate an ionic feature between ${\mathrm{Li}}^{+}$ and ${[\mathrm{N}{\mathrm{H}}_{2}]}^{\ensuremath{-}}$. The internal bonding of ${[\mathrm{N}{\mathrm{H}}_{2}]}^{\ensuremath{-}}$ anions is primarily covalent. The internal $\mathrm{N}\ensuremath{-}\mathrm{H}$ bending and stretching vibrations of ${[\mathrm{N}{\mathrm{H}}_{2}]}^{\ensuremath{-}}$ anions yield $\ensuremath{\Gamma}$-phonon modes around 1500 and $3400\phantom{\rule{0.3em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}1}$, respectively. These can be fairly reproduced by the molecular approximation, suggesting a strong internal bonding of ${[\mathrm{N}{\mathrm{H}}_{2}]}^{\ensuremath{-}}$ anions. The heat of formation for the fully hydriding reaction of ${\mathrm{Li}}_{3}\mathrm{N}$ is predicted as $\ensuremath{-}85\phantom{\rule{0.3em}{0ex}}\mathrm{kJ}∕\mathrm{mol}$ ${\mathrm{H}}_{2}$ which agrees well with the experimental value. Some discussions are also presented for the properties of ${\mathrm{Li}}_{3}\mathrm{N}$.

First-principles calculations have been performed on lithium borohydride $\mathrm{Li}\mathrm{B}{\mathrm{H}}_{4}$ using the ultrasoft pseudopotential method, which is a potential candidate for hydrogen storage materials due to its extremely large gravimetric capacity of $18\phantom{\rule{0.3em}{0ex}}\text{mass}\phantom{\rule{0.3em}{0ex}}%$ hydrogen. We focus on an orthorhombic phase observed at ambient conditions and predict its fundamental properties; the structural properties, electronic properties, dielectric properties, vibrational properties, and the heat of formation. The calculation gives a nearly ideal tetrahedral shape for $\mathrm{B}{\mathrm{H}}_{4}$ complexes, although the recent experiment suggests that their configuration is strongly distorted [J-Ph. Souli\'e et al., J. Alloys Compd. 346, 200 (2002)]. Analyses for the electronic structure and the Born effective charge tensors indicate that Li atoms are ionized as ${\mathrm{Li}}^{+}$ cations. The internal bonding of ${[\mathrm{B}{\mathrm{H}}_{4}]}^{\ensuremath{-}}$ anions is primarily covalent. The high-frequency dielectric permittivity tensor ${\ensuremath{\epsilon}}_{\ensuremath{\infty}}$ is predicted as almost isotropic, but the static dielectric permittivity tensor ${\ensuremath{\epsilon}}_{0}$ as considerably anisotropic. The $\mathrm{\ensuremath{\Gamma}}$-phonon eigenmodes can be classified into three groups, namely, the librational modes involving the displacements of ${\mathrm{Li}}^{+}$ cations (less than $500\phantom{\rule{0.3em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}1}$), and the internal B-H bending and stretching modes of ${[\mathrm{B}{\mathrm{H}}_{4}]}^{\ensuremath{-}}$ anions (around 1100 and $2300\phantom{\rule{0.3em}{0ex}}{\mathrm{cm}}^{\ensuremath{-}1}$, respectively). The molecular approximation fairly reproduces the phonon frequencies in the latter two groups, implying the strong internal bonding of $\mathrm{B}{\mathrm{H}}_{4}$ complexes. The librational modes have significant contributions to the large anisotropies of ${\ensuremath{\epsilon}}_{0}$. The agreement of the heat of formation with the experimental value is reasonably good.

We found that CaSi reversibly absorbs and desorbs hydrogen. First-principles calculations theoretically indicated that CaSi hydride is thermodynamically stable. The hydriding and dehydriding properties of CaSi were experimentally determined using pressure-composition (p‐c) isotherms and x-ray diffraction analysis. The p‐c isotherms clearly demonstrated plateau pressures in a temperature range of 473–573K. The maximum hydrogen content was 1.9wt% under a hydrogen pressure of 9MPa at 473K. The reversible hydriding and dehydriding properties of CaSi suggest the potential of metal silicides for hydrogen storage.

The formation condition of an intermediate compound of LiBH4 during the partial dehydriding reaction and its local atomistic structure have been experimentally investigated. LiBH4 changes into an intermediate compound accompanying the release of approximately 11mass% of hydrogen at 700–730K. The Raman spectra indicate that the B–H bending and stretching modes of the compound appear at lower and higher frequencies, respectively, as compared to those of LiBH4. These features are consistent with the theoretical calculation on the monoclinic Li2B12H12, consisting of Li+ and [B12H12]2− ions, as a possible intermediate compound of LiBH4.