First principle calculations of alkali hydride electronic structures

Abstract

Electronic structure, volume optimization, bulk moduli, elastic constants, and frequencies of the transversal optical vibrations in LiH, NaH, KH, RbH, and CsH are calculated using the full potential augmented plane wave method, extended with local orbitals, and the full potential linearized augmented plane wave method. The obtained results show some common features in the electronic structure of these compounds, but also clear differences, which cannot be explained using simple empirical trends. The differences are particularly prominent in the electronic distributions and interactions in various crystallographic planes. In the light of these findings we have elaborated some selected experimental results and discussed several theoretical approaches frequently used for the description of various alkali hydride properties.

Ab initio study of MgH2 formation

“…The hydrides of the first [1] and especially the second group [2] of periodic table have been suggested as potential candidates for the bulk storage of hydrogen. Among them, magnesium hydride has been systematically studied due to its high hydrogen capacity by weight and volume and its low cost.…”

Electronic Principles of Hydrogen Incorporation and Dynamics in Metal Hydrides

“…They are also systems of considerable theoretical interest [15][16][17][18][19][20][21][22][23][24][25] convenient for investigation of fundamental interactions that are expected to be important in new complex materials [26][27][28][29][30][31][32]. Although significant experimental and theoretical work has been devoted to the study of metal hydrides, some of their fundamental features, such as details of valence and conduction bands and energy gap structures, the charge transfer and the charge distribution, the origin and the importance of various contributions to the bonding between metal and hydrogen (M-H) and hydrogen and hydrogen (H-H), are not yet fully clarified.…”

“…A complete elaboration of these topics from the first principles is indispensable for understanding of H-behavior in metallic systems in general. Moreover, extensive data about metal hydrides have been obtained and explained using various, and sometimes contradictory, concepts [15][16][17][18][20][21][22][23][24][25][26][33][34][35][36][37][38][39]. However, a coherent approach valid for all metal hydrides is still missing.…”

“…For that purpose we extended our previous experimental [33,44,45], and known numerical [20,23,32,44,65] results by first-principle calculations of the electronic structures of various metal hydrides using the Full Potential Augmented Plane Waves extended (FP-APW+lo) and the Full Potential Linearized Augmented Plane Waves (FP-LAPW+LO) with addition of local orbitals methods, as implemented in the WIEN2k software package [73], and the pseudopotentials method, as implemented in Abinit software package.…”

Field-Driven Dynamics of Correlated Electrons in LiH andNaBH4Revealed by Femtosecond X-Ray Diffraction

“…So far, most experimental studies had their focus on the temporal (or frequency) aspects, i.e., on transient macroscopic polarizations and currents [1][2][3][4][5][6][7][8]. The results have given only indirect insight into Coulomb mediated electronic correlations which-in contrast-have been the subject of extensive theoretical work [9][10][11][12][13][14][15][16][17][18][19][20]. Moreover, the real space dynamics of charges on atomic length scales, which are a probe of electronic correlations, have remained mostly unresolved.…”