We have used diffusion Monte Carlo (DMC) calculations to study the structural properties of magnesium hydride (MgH$_2$), including the pressure-volume equation of state, the cohesive energy and the enthalpy of formation from magnesium bulk and hydrogen gas. The calculations employ pseudopotentials and B-spline basis sets to expand the single particle orbitals used to construct the trial wavefunctions. Extensive tests on system size, time step, and other sources of errors, performed on periodically repeated systems of up to 1050 atoms, show that all these errors together can be reduced to below 10 meV per formula unit. We find excellent agreement with the experiments for the equilibrium volume of both the Mg and the MgH$_2$ crystals. The cohesive energy of the Mg crystal is found to be 1.51(1) eV, and agrees perfectly with the experimental value of 1.51 eV. The enthalpy of formation of MgH$_2$ from Mg bulk and H$_2$ gas is found to be $0.85 \pm 0.01$ eV/formula unit, or $82 \pm 1$ kJ/mole, which is off the experimental one of $76.1 \pm 1$ kJ/mole only by 6 kJ/mole. This shows that DMC can almost achieve chemical accuracy (1 kcal/mole) on this system. Density functional theory errors are shown to be much larger, and depend strongly on the functional employed.
Machine learning to explore high-entropy alloys with desired enthalpy for room-temperature hydrogen storage: Prediction of density functional theory and experimental data
Chemical transformation of MgH2/V2O5 composite to Mg-V-O rock salt and its influence on the electrochemical Li conversion and hydrogen storage characteristics of MgH2
University of Aveiro（阿威罗大学）；LASI - Intelligent Systems Associate Laboratory（智能系统联合实验室）；International Iberian Nanotechnology Laboratory (INL)（伊比利亚纳米技术国际实验室）
Materials for hydrogen-based energy storage: Past, recent progress and future outlook
氢化镁在固体储氢材料方面占有最大的份额。为IEA Task 32 Hydrogen Based Energy Storage做出贡献的国际镁专家组最近发表了两篇综述论文，介绍了该小组的活动重点是氢化镁基材料和用于氢和能量存储的镁基化合物。这篇综述文章不仅概述了镁基复合材料的基本方面及其应用的最新活动，而且还介绍了该主题的历史概述，并概述了未来的发展。重点介绍了Mg-H体系在极压下的理论和实验研究、MgH 2体系的动力学和热力学研究、纳米结构研究、新型镁基化合物和新型复合材料研究以及镁基储氢体系中的催化作用研究。最后，热能存储和放大氢存储系统容纳MgH 2。
Ab-initio insights into the structural, elastic, bonding, and thermophysical properties of UHx (x = 1, 2, 3, 5, 6, 7, 8) under pressure: possible relevance to high-Tc superconductivity
