[1] [1] JAIN I P, JAIN P, JAIN A. Novel hydrogen storage materials: a review of lightweight complex hydrides［J］. Journal of Alloys and Compounds, 2010, 503(2): 303-339.

[2] [2] ZHANG B, WU Y. Recent advances in improving performances of the lightweight complex hydrides Li-Mg-N-H system［J］. Progress in Natural Science: Materials International, 2017, 27(1): 21-33.

[3] [3] WANG J H, LIU T, WU G T, et al. Potassium-modified Mg(NH2)2/2LiH system for hydrogen storage［J］. Angewandte Chemie International Edition, 2009, 48(32): 5828-5832.

[4] [4] LI C, LIU Y F, MA R J, et al. Superior dehydrogenation/hydrogenation kinetics and long-term cycling performance of K and Rb cocatalyzed Mg(NH2)2-2LiH system［J］. ACS Applied Materials & Interfaces, 2014, 6(19): 17024-17033.

[5] [5] ZHANG B, YUAN J G, WU Y. Catalytic effects of Mg(BH4)2 on the desorption properties of 2LiNH2-MgH2 mixture［J］. International Journal of Hydrogen Energy, 2019, 44(35): 19294-19301.

[6] [6] QIU S J, GAO W, MA X Y, et al. Enhanced thermal diffusivity and dehydrogenation of 2LiNH2MgH2 by doping with super activated carbon［J］. International Journal of Hydrogen Energy, 2018, 43(30): 13975-13980.

[7] [7] YAN M Y, SUN F, LIU X P, et al. Effects of compaction pressure and graphite content on hydrogen storage properties of Mg(NH2)2-2LiH hydride［J］. International Journal of Hydrogen Energy, 2014, 39(34): 19656-19661.

[8] [8] MA L P, DAI H B, LIANG Y, et al. Catalytically enhanced hydrogen storage properties of Mg(NH2)2 + 2LiH material by graphite-supported Ru nanoparticles［J］. The Journal of Physical Chemistry C, 2008, 112(46): 18280-18285.

[9] [9] ZHU X L, HAN S M, ZHAO X, et al. Improving hydrogen storage performance of Li-Mg-N-H system by adding niobium hydride［J］. Rare Metals, 2014, 33(1): 86-90.

[10] [10] SHAHI R R, YADAV T P, SHAZ M A, et al. Studies on dehydrogenation characteristic of Mg(NH2)2/LiH mixture admixed with vanadium and vanadium based catalysts (V, V2O5 and VCl3)［J］. International Journal of Hydrogen Energy, 2010, 35(1): 238-246.

[11] [11] SHAHI R R, MISHRA R K, SHUKLA V, et al. Enhanced hydrogenation characteristics of Li-Mg-N-H system catalyzed with TiO2 nanoparticles; a mechanistic approach［J］. International Journal of Hydrogen Energy, 2017, 42(49): 29350-29359.

[12] [12] RIJSSENBEEK J, GAO Y, HANSON J, et al. Crystal structure determination and reaction pathway of amide-hydride mixtures［J］. Journal of Alloys and Compounds, 2008, 454(1/2): 233-244.

[13] [13] WANG Y, CHOU M Y. First-principles study of cation and hydrogen arrangements in the Li-Mg-N-H hydrogen storage system［J］. Physical Review B, 2007, 76: 014116.

[14] [14] VELIKOKHATNYI O I, KUMTA P N. Energetics of the lithium-magnesium imide-magnesium amide and lithium hydride reaction for hydrogen storage: an ab initio study［J］. Materials Science and Engineering: B, 2007, 140(1/2): 114-122.

[15] [15] WANG Q, CHEN Y G, GAI J G, et al. Role of amino anion in metal amides/imides for hydrogen storage: a first principle study［J］. The Journal of Physical Chemistry C, 2008, 112(46): 18264-18269.

[16] [16] WANG Q, CHEN Y G, WU C L, et al. Electronic structure, chemical bond and thermal stability of hydrogen absorber Li2MgN2H2［J］. Chinese Science Bulletin, 2009, 54(3): 497-503.

[17] [17] WANG Q, CHEN Y G, NIU G, et al. Nature of Ti species in the Li-Mg-N-H system for hydrogen storage: a theoretical and experimental investigation［J］. Industrial & Engineering Chemistry Research, 2009, 48(11): 5250-5254.

[18] [18] CLARK S J, SEGALL M D, PICKARD C J, et al. First principles methods using CASTEP［J］. Zeitschrift Für Kristallographie - Crystalline Materials, 2005, 220(5/6): 567-570.

[19] [19] HOHENBERG P, KOHN W. Inhomogeneous electron gas［J］. Physical Review, 1964, 136(3B): B864-B871.

[20] [20] PERDEW J P, BURKE K, ERNZERHOF M. Generalized gradient approximation made simple［J］. Physical Review Letters, 1996, 77(18): 3865-3868.

[21] [21] VANDERBILT D. Soft self-consistent pseudopotentials in a generalized eigenvalue formalism［J］. Physical Review B, 1990, 41(11): 7892-7895.

[22] [22] MONKHORST H J, PACK J D. Special points for Brillouin-zone integrations［J］. Physical Review B, 1976, 13(12): 5188-5192.

[23] [23] PFROMMER B G, CT M, LOUIE S G, et al. Relaxation of crystals with the quasi-Newton method［J］. Journal of Computational Physics, 1997, 131(1): 233-240.

[24] [24] HAMMER B, HANSEN L B, NRSKOV J K. Improved adsorption energetics within density-functional theory using revised Perdew-Burke-Ernzerhof functionals［J］. Physical Review B, 1999, 59(11): 7413-7421.

[25] [25] FRANCIS G P, PAYNE M C. Finite basis set corrections to total energy pseudopotential calculations［J］. Journal of Physics: Condensed Matter, 1990, 2(19): 4395-4404.