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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on Li(BH)5 by Materials Project

Li(BH)5 crystallizes in the hexagonal P6_422 space group. The structure is one-dimensional and consists of three Li(BH)5 ribbons oriented in the (0, 1, 0) direction. Li is bonded in a 6-coordinate geometry to six H atoms. There are a spread of Li–H bond distances ranging from 2.05–2.25 Å. There are three inequivalent B sites. In the first B site, B is bonded in a distorted single-bond geometry to one H atom. The B–H bond length is 1.21 Å. In the second B site, B is bonded in a distorted single-bond geometry to one H atom. The B–H bond length is 1.21 Å. In the third B site, B is bonded in a distorted single-bond geometry to one H atom. The B–H bond length is 1.20 Å. There are three inequivalent H sites. In the first H site, H is bonded in a distorted T-shaped geometry to two equivalent Li and one B atom. In the second H site, H is bonded in a water-like geometry to one Li and one B atom. In the third H site, H is bonded in a water-like geometry to one Li and one B atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Li2(BH)11 by Materials Project

(Li(BH)3)2(BH)5 crystallizes in the monoclinic C2 space group. The structure is one-dimensional and consists of ten boranediylradical molecules and two Li(BH)3 ribbons oriented in the (1, 0, 0) direction. In each Li(BH)3 ribbon, there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded in a distorted see-saw-like geometry to four H+0.64+ atoms. There is two shorter (1.88 Å) and two longer (2.11 Å) Li–H bond length. In the second Li1+ site, Li1+ is bonded in a distorted see-saw-like geometry to four H+0.64+ atoms. There is two shorter (1.88 Å) and two longer (2.11 Å) Li–H bond length. There are three inequivalent B+0.82- sites. In the first B+0.82- site, B+0.82- is bonded in a distorted single-bond geometry to one H+0.64+ atom. The B–H bond length is 1.21 Å. In the second B+0.82- site, B+0.82- is bonded in a distorted single-bond geometry to one H+0.64+ atom. The B–H bond length is 1.21 Å. In the third B+0.82- site, B+0.82- is bonded in a distorted single-bond geometry to one H+0.64+ atom. The B–H bond length is 1.21 Å. There are three inequivalent H+0.64+ sites. In the first H+0.64+ site, H+0.64+ is bonded in a T-shaped geometry to two Li1+ and one B+0.82- atom. In the second H+0.64+ site, H+0.64+ is bonded in a water-like geometry to one Li1+ and one B+0.82- atom. In the third H+0.64+ site, H+0.64+ is bonded in a water-like geometry to one Li1+ and one B+0.82- atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Li(BH)6 by Materials Project

Li(BH)4(BH)2 crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of eight boranediylradical molecules and four Li(BH)4 clusters. In each Li(BH)4 cluster, Li is bonded in a 5-coordinate geometry to four H atoms. There are a spread of Li–H bond distances ranging from 1.94–2.26 Å. There are four inequivalent B sites. In the first B site, B is bonded in a single-bond geometry to one H atom. The B–H bond length is 1.20 Å. In the second B site, B is bonded in a single-bond geometry to one H atom. The B–H bond length is 1.20 Å. In the third B site, B is bonded in a single-bond geometry to one H atom. The B–H bond length is 1.20 Å. In the fourth B site, B is bonded in a single-bond geometry to one H atom. The B–H bond length is 1.21 Å. There are four inequivalent H sites. In the first H site, H is bonded in a bent 120 degrees geometry to one Li and one B atom. In the second H site, H is bonded in a distorted L-shaped geometry to one Li and one B atom. In the third H site, H is bonded in an L-shaped geometry to one Li and one B atom. In the fourth H site, H is bonded in a water-like geometry to one Li and one B atom.

36 MATERIALS SCIENCE↗
DOE OSTI2021

The morphology of the X-ray afterglows and of the jetted GeV emission in long GRBs

ABSTRACT We recall evidence that long gamma-ray bursts (GRBs) have binary progenitors and give new examples. Binary-driven hypernovae (BdHNe) consist of a carbon–oxygen core (COcore) and a neutron star (NS) companion. For binary periods ∼5 min, the COcore collapse originates the subclass BdHN I characterized by (1) an outstanding supernova (SN; the ‘SN-rise’); (2) a black hole (BH), born from the NS collapse by SN matter accretion, leading to a GeV emission with luminosity $L_{\rm GeV} = A_{\rm GeV}\, t^{-\alpha _{\rm GeV}}$, observed only in some cases; and (3) a new NS (νNS), born from the SN, originating from the X-ray afterglow with $L_\mathrm{ X} = A_{\rm X}\, t^{-\alpha _{\rm X}}$, observed in all BdHN I. We record 378 sources and present for four prototype GRBs 130427A, 160509A, 180720B, and 190114C: (1) spectra, luminosities, SN-rise duration; (2) AX, αX = 1.48 ± 0.32, and (3) the νNS spin time evolution. We infer (i) AGeV, αGeV = 1.19 ± 0.04 and (ii) the BdHN I morphology from time-resolved spectral analysis, three-dimensional simulations, and the GeV emission presence/absence in 54 sources within the Fermi-Large Area Telescope boresight angle. For 25 sources, we give the integrated and time-varying GeV emission, 29 sources have no GeV emission detected and show X/gamma-ray flares previously inferred as observed along the binary plane. The 25/54 ratio implies the GeV radiation is emitted within a cone of half-opening angle ≈60° from the normal to the orbital plane. We deduce BH masses of 2.3–8.9 M⊙ and spin of 0.27–0.87 by explaining the GeV emission from the BH rotational energy extraction, while their time evolution validates the BH mass–energy formula.

79 ASTRONOMY AND ASTROPHYSICS↗