First-principles calculations of structural, electronic, and thermodynamic properties of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msub><mml:mi mathvariant="normal">Na</mml:mi><mml:mn>2</mml:mn></mml:msub><mml:mi mathvariant="normal">Be</mml:mi><mml:msub><mml:mi mathvariant="normal">H</mml:mi><mml:mn>4</mml:mn></mml:msub></mml:mrow></mml:math>

Hu, Chen; Wang, Y. M.; Chen, D. M.; Xu, Dongdong; Yang, Kaishuai

doi:10.1103/physrevb.76.144104

Cited by 11 publications

(8 citation statements)

References 42 publications

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“…Following our previous investigations on complex alkali beryllium hydrides Li 2 BeH 4 ͑Ref. 33͒ and Na 2 BeH 4 , 34 we predict alternative ground-state crystal structures for LiBeH 3 and temperature-and pressure-induced phase transitions to different high-temperature and high-pressure phases. Our investigations are based on a much larger structure database ͑containing, in particular, all previously proposed equilibrium structures͒ and total-energy, electronic-structure, and phonon calculations based on DFT.…”

Section: Introductionmentioning

confidence: 64%

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Crystal structure prediction of LiBeH3 using ab initio total-energy calculations and evolutionary simulations

Oganov

Wang

et al. 2008

The Journal of Chemical Physics

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The stable crystal structure of LiBeH(3) is predicted on the basis of ab initio total-energy calculations using density-functional theory and an extended database of candidate structures and using global optimizations based on an evolutionary algorithm. At the level of density-functional theory, a CaSiO(3)_1-type structure with space group P2(1)/c, containing BeH(4) tetrahedra linked in chains, is the ground-state structure of LiBeH(3) (alpha-LiBeH(3)). It is found to be lower in energy than the structures proposed in previous studies. The analysis of the electronic structure shows that alpha-LiBeH(3) is an insulator with a band gap of about 4.84 eV and exhibits strong covalent bonding in the BeH(4) tetrahedral complexes. Calculations at finite temperatures and high pressures suggest that at T=408 K and ambient pressure a structural transition from alpha-LiBeH(3) (CaSiO(3)-type) to a YBO(3)-type structure with space group Cmcm occurs and that at a pressure of 7.1 GPa alpha-LiBeH(3) undergoes a pressure-induced structural transition from the alpha-phase to a MgSiO(3)-type structure with space group C2/c. The calculated enthalpies of formation (-45.36 and -30.12 kJ/mol H(2) without and with zero-point energy corrections) are in good agreement with the experimental result, indicating that LiBeH(3) is a potential hydrogen storage material with low activation barriers for hydrogen desorption.

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Section: Introductionmentioning

confidence: 64%

“…Unlike in other complex hydrides such as NaAlH 4 ͑Ref. 71͒ or Na 2 BeH 4 ,34 the frequency ranges of libratonal and bending modes overlap in the ␣and MgSiO 3 -type phases of LiBeH 3 . The highest frequencies of Be-H stretching modes are approximately 200 cm −1 higher than in Na 2 BeH 4 ͑Ref.…”

mentioning

confidence: 71%

Crystal structure prediction of LiBeH3 using ab initio total-energy calculations and evolutionary simulations

Oganov

Wang

et al. 2008

The Journal of Chemical Physics

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“…The PW91 form of the generalized gradient approximation (GGA) was applied as the exchange-correlation potential. The structure optimizations for the seven complex hydrides in this study were carried out using the Broyden-Fletcher-Goldfarb-Shanno (BFGS) algorithm by allowing all atomic positions to vary but all cell parameters to be fixed at the lattice parameters given in [1,3,[16][17][18][19][20][21][22]. Actually, we also tested the influence of the fixed (or relaxed) lattice parameters on the properties we were interested in, and the results show that there is no significant difference, e.g.…”

Section: Computational Detailsmentioning

confidence: 99%

“…What role does it play in the thermal stability of A m (MH 4 ) n ? As pointed out by many researchers, A m (MH 4 ) n complex hydrides can be considered to cohere mainly by the ionic bonding between atom A and the MH 4 complex and the covalent bonding between M and H atoms [14,[16][17][18]21]. According to the definition of bond energy of a covalent bond [37], the energy of the bond between M and H atoms can be calculated by…”

Section: The Relationship Between Bonding Interaction and Cohesive En...mentioning

confidence: 99%

A first principles study of the thermal stability of A_m(MH₄)_nlight complex hydrides

Wang

Liu

Rong

et al. 2010

J. Phys.: Condens. Matter

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From the physical point of view, the cohesive energy of a reactant is preferable to its formation energy for characterizing its influence on the reaction processes from the reactants to the products. In fact it has been found that there is a certain correlation between the experimental hydrogen desorption temperature and the cohesive energy calculated by a first principles method for a series of A(m)(MH(4))(n) (A = Li, Na, Mg; M = Be, B, Al) light complex hydrides (including Na(2)BeH(4), Li(2)BeH(4), NaAlH(4), LiAlH(4), Mg(AlH(4))(2), LiBH(4) and NaBH(4)), which suggests that cohesive energy may be a useful physical quantity for evaluating the hydrogen desorption ability of complex hydrides, especially in cases when dehydrogenation products have unknown crystal structures, or may even be unknown. To understand this correlation more deeply, the ionic interaction between A and the MH(4) complex and the covalent interaction between M and H were calculated and their contributions to the cohesive energy evaluated quantitatively. The calculated results show that the covalent M-H interaction in the MH(4) complex is the dominant part of the cohesive energy E(coh) (up to more than 75%) and hardly changes during high-pressure structural transitions of A(m)(MH(4))(n). It was also found that low electronegativity of M or high electronegativity of A is responsible for the weak covalent M-H interaction and finally leads to the low thermodynamic stability of A(m)(MH(4))(n), suggesting that complex hydrides A(m)(MH(4))(n) can be destabilized by partial substitution of M (A) with an element with electronegativity lower (higher) than Ms (As). This conclusion has been confirmed by lots of experimental results and may be a useful guideline for the future design of new complex hydrides of the type A(m)(MH(4))(n).

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“…MBH 4 → MH + B + 3/2H 2 (2) Theoretical investigation of structural, electronic and thermodynamic properties of crystalline Na 2 BeH 4 and the structural transition from α-to β-Na 2 BeH 4 has been performed in [18].…”

Section: Introductionmentioning

confidence: 99%

Gaseous Metal Hydrides MBeH3 and M2BeH4 (M = Li, Na): Quantum Chemical Study of Structure, Vibrational Spectra and Thermodynamic Properties

Shomari¹

2016

IJMSA

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First-principles calculations of structural, electronic, and thermodynamic properties ofNa2BeH4

Cited by 11 publications

References 42 publications

Crystal structure prediction of LiBeH3 using ab initio total-energy calculations and evolutionary simulations

Crystal structure prediction of LiBeH3 using ab initio total-energy calculations and evolutionary simulations

A first principles study of the thermal stability of A_m(MH₄)_nlight complex hydrides

Gaseous Metal Hydrides MBeH<sub>3</sub> and M<sub>2</sub>BeH<sub>4</sub> (M = Li, Na): Quantum Chemical Study of Structure, Vibrational Spectra and Thermodynamic Properties

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First-principles calculations of structural, electronic, and thermodynamic properties ofNa2BeH4

Cited by 11 publications

References 42 publications

Crystal structure prediction of LiBeH3 using ab initio total-energy calculations and evolutionary simulations

Crystal structure prediction of LiBeH3 using ab initio total-energy calculations and evolutionary simulations

A first principles study of the thermal stability of Am(MH4)nlight complex hydrides

Gaseous Metal Hydrides MBeH&lt;sub&gt;3&lt;/sub&gt; and M&lt;sub&gt;2&lt;/sub&gt;BeH&lt;sub&gt;4&lt;/sub&gt; (M = Li, Na): Quantum Chemical Study of Structure, Vibrational Spectra and Thermodynamic Properties

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A first principles study of the thermal stability of A_m(MH₄)_nlight complex hydrides

Gaseous Metal Hydrides MBeH<sub>3</sub> and M<sub>2</sub>BeH<sub>4</sub> (M = Li, Na): Quantum Chemical Study of Structure, Vibrational Spectra and Thermodynamic Properties