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All sourcesNASA NTRSDOE OSTI
NASA NTRS1979

Photochemistry of bromoacetylene - Formation of HBr and quenching of excited Br/4 2P 0 1/2/

The photolysis of bromacetylene is examined by means of vacuum ultraviolet flash photolysis-kinetic spectroscopy, with attention given to the production of Br atoms in the 2P 0 3/2 and 2P 0 1/2 states, the production of HBr, and UV absorption attributable to the ethynyl radical. Although Br(2P 0 1/2) and Br(2P 0 3/2) were both directly observed at the shortest delay time after the flash, strongly indicating the presence of the ethynyl radical, transient absorption by C2H was not detected in the range 125 to 180 nm. Quenching rate constants for the decay of the 2P 0 1/2 state of Br, which is observed to form concurrently with the ground state, are derived for quenching by He, CH2Br, CF4, and D2 from the pseudo-first-order decay rates. HBr was observed as a secondary photolysis product, and a model of its formation by the exothermic reaction of ground-state atoms with C2HBR, coupled with the secondary production of Br atoms, is found to agree well with the experiment.

Laufer, A. H.↗
NASA NTRS1984

Brackett-alpha line profiles of young stellar objects

Profiles of the Br-alpha line of H I at a velocity resolution of 45 km/s are presented for the compact imbedded infrared objects BN, S106/IRS 3, GLS 490, GL 961, GL 989, Mon. R2/IRS 2, and for the visible objects LkH-alpha 101, T Tau, and R Mon. A proportionality obtained between Br-alpha luminosity and bolometric luminosity is shown to extend over three orders of magnitude, supporting the idea that the physical conditions and gas motions in the circumstellar envelopes of stellar objects are closely related over a wide range of luminosities. The Br-alpha line strengths are compared to radio continuum flux densities in the context of stellar wind models. Momentum deposition rates deduced from Br-alpha or radio continuum fluxes are consistent with those available in the radiation fields, which appear capable of driving the ionized gas outflows in the vicinity of the core sources. The results of a comparison of the H-alpha and Br-alpha profiles for T Tau are discussed.

Persson, S. E.↗
NASA NTRS1986

Effect of simulated weightlessness on exercise-induced anaerobic threshold

The effect of simulated weightlessness, induced by ten days of continuous bedrest (BR) in the -6 deg head-down position, on the exercise-induced anaerobic threshold (AT) was determined by comparing specific ventilatory and gas-exchange measurements during an incremental ergometer test performed before and after BR. The primary index for determining the exercise-induced AT values of each subject was visual identification of the workrate or oxygen uptake (VO2) at which the ratio of the expired minute ventilation volume (VE) to VO2 exhibited a systematic increase without a concomitant increase in the VE/VCO2 value. Following BR, the mean VO2max of the subjects decreased by 7.0 percent, and the AT decreased from a mean of 1.26 L/min VO2 before BR to 0.95 L/min VO2 after BR. The decrease in AT was manifested by a decrease in both absolute and relative workrates. The change in AT correlated significantly with the change in plasma volume but not with the change in VO2max. The results suggest that the reduction in AT cannot be completely explained by the reduction in VO2, and that the AT decrease is associated with the reduction in intravascular fluid volume.

Convertino, V. A.↗
NASA NTRS1997

Multiplexed Holographic Data Storage in Bacteriorhodopsin

High density optical data storage, driven by the information revolution, remains at the forefront of current research areas. Much of the current research has focused on photorefractive materials (SBN and LiNbO3) and polymers, despite various problems with expense, durability, response time and retention periods. Photon echo techniques, though promising, are questionable due to the need for cryogenic conditions. Bacteriorhodopsin (BR) films are an attractive alternative recording medium. Great strides have been made in refining BR, and materials with storage lifetimes as long as 100 days have recently become available. The ability to deposit this robust polycrystalline material as high quality optical films suggests the use of BR as a recording medium for commercial optical disks. Our own recent research has demonstrated the suitability of BR films for real time spatial filtering and holography. We propose to fully investigate the feasibility of performing holographic mass data storage in BR. Important aspects of the problem to be investigated include various data multiplexing techniques (e.g. angle- amplitude- and phase-encoded multiplexing, and in particular shift-multiplexing), multilayer recording techniques, SLM selection and data readout using crossed polarizers for noise rejection. Systems evaluations of storage parameters, including access times, memory refresh constraints, erasure, signal-to-noise ratios and bit error rates, will be included in our investigations.

Mehrl, David J.↗
NASA NTRS1997

Kinetics of the Reactions of O((sup 3)P) and Cl((sup 2)P) with HBr and Br2

A laser flash photolysis-resonance fluorescence technique has been employed to study the kinetics of reactions (1)-(4) as a function of temperature. (1) O((sup 3)P) + Br2 yields BrO + Br((sup 2)P(sub 3/2)) at 255-350 K; (2) Cl((sup 2)P) + Br2 yields BrCl + Br((sup 2)P(sub 3/2)) at 298-401 K; (3) O((sup 3)P) + HBr yields OH + Br((sup 2)P(sub J)) at 250-402 K; (4) Cl((sup 2)P) + HBr yields HCl + Br((sup 2)P(sub J)) at 257-404 K. In all cases, the concentration of the excess reagent, i.e, HBr or Br2, was measured in situ in the slow flow system by UV-visible photometry. Heterogeneous dark reactions between XBr (X equals H or Br) and the photolytic precursors for Cl((sup 2)P) and O((sup 3)P) (Cl2 and O3, respectively) were avoided by injecting minimal amounts of precursor into the reaction mixture immediately upstream from the reaction zone. The following Arrhenius expressions summarize our results (errors are 2 sigma and represent precision only, units are cu cm/(molecule.s): k(sub 1) = (1.76 +/- 0.80) x 10(exp -11 exp[(40 +/- 100)/T]; k(sub 2) = (2.40 +/- 1.25) x 12(exp -10) exp[-(144 +/- 176)/T]; k(sub 3) = (5.11 +/- 2.82) x 10(exp -12) exp[-(1450 +/- 160)/T]; k(sub 4) = (2.25 +/- 0.56) x 10(exp -11) exp[-(400 +/- 80)/T]. The consistency (or lack thereof) of our results with those reported in previous kinetics and dynamics studies of reactions (1)-(4) is discussed.

Nicovich, J. M.↗
NASA NTRS2000

Deconditioning and Reconditioning: Humans in Stressful Environments

Deconditioning is an integrated physiological response of the body to a reduction in metabolic rate; that is, to a reduction in energy use or in exercise level. While it may involve assumption of a horizontal body position, it certainly perturbs bodily homeostasis - at least temporarily. The reduction in physical activity that causes deconditioning is often associated with an increase in the time spent, for whatever reason, in a sitting or horizontal position. As a result, orthostatic factors may also contribute to the deconditioning mechanism. The word decondition may be defined as "1: to cause extinction of (a conditioned response) 2: to cause to lose physical fitness". This definition implies that psychological/emotional factors may accompany physical deconditioning, and it is this interpretation of the word that is used throughout this volume. It is apparent that deconditioning plays a major role in the mechanism of the general adaptive (homeostatic) response that is initiated by exposure to prolonged bed rest (BR). And the total homeostatic response to BR involves more than deconditioning per se. For example, it has been shown that the restoration of plasma volume and maximal work capacity after 4 weeks of BR deconditioning left other bodily functions (submaximal exercise oxygen uptake and cardiac output, leg proprioception and posterior leg muscle thickness and volume, head-up tilt tolerance, and sleep quality) functioning at decreased levels. The precise effect of deconditioning on BR homeostasis is difficult to determine, because the fundamental interactive neuro-endocrine-immune control networks that facilitate conditioning and deconditioning also act to maintain basic wholebody homeostasis. For example, is the mechanism of BR-induced deconditioning independent of the mechanism that provokes concomitant orthostatic intolerance; that is, fainting? Assumption of the recumbent body position for prolonged periods of time, results in a new adaptive-homeostatic state. This state occurs in response to the mutually interactive effects of the change in bodily position (hydrostatic pressure), to the virtual elimination of longitudinal pressure on the bones, to the increased confinement with possible reduction in total daily energy (exercise) expenditure, to the reorientation of stimuli within the vestibular organs, and (often) to altered socio-psychological conditions. The exercise-training (reconditioning) syndrome affects total body homeostasis by facilitating increases in work capacity and endurance, whereas deconditioning decreases physical performance. There are many interrelated factors that influence the control parameters that seek to maintain the adaptive conditioning-deconditioning syndrome. These control parameters can be better elucidated by subjecting otherwise healthy ambulatory people to various stresses, such as exercise training and prolonged spaceflight, bed rest, water immersion, hyperbaria, and isolation and confinement. Changes in control parameters will be manifested in muscle function, orthostatic tolerance, cardiorespiratory responses, musculo-skeletal systems, free-radical processes, and body thermoregulation with overarching effects on the subjects' psycho-sociological states. A discussion of these factors and the control parameters constitutes the substance of this volume. Special emphasis is placed on delineating practical applications of the findings that will be of special interest to physicians, nurses, and other health-care workers.

Greenleaf, John E.↗
NASA NTRS1995

Cardiovascular and Body Fluid Adjustments During Bed Rest and Space Flight

Although a few scientific bed rest (BR) studies were conducted soon after World War II, advent of the space program provided impetus for utilizing prolonged (days-months) BR, which employed the horizontal or 6 degree head-down tilt (HDT) body positions, to simulate responses of healthy people to microgravity. Shorter (hours) HDT protocols were used to study initial mechanisms of the acclimation-deconditioning (reduction of physical fitness) syndromes. Of the major physiological factors modified during BR, reduced force on bones, ligaments, and muscles, and greatly reduced hydrostatic pressure within the cardiovascular system, the latter: which involves shifts of blood from the lower extremities into the upper body, increase in central venous pressure, and diuresis, appears to be the initial stimulus for acclimation. Increase in central venous pressure occurs in subjects during weightless parabolic flight, but not in astronauts early during orbital flight. But significant reduction in total body water (hypohydration) and plasma volume (hypovolemia) occurs in subjects during both BR and microgravity. Response of interstitial fluid volume is not as clear, It has been reported to increase during BR, and it may have increased in Skylab II and IV astronauts. Reduction of total body water, and greater proportional reduction of extracellular volume, indicates increased cellular volume which may contribute to inflight cephalic edema. Cerebral pressure abates after a few days of HDT, but not during flight. accompanied by normal (eugravity) blood constituent concentrations suggesting some degree of acclimation had occurred. But during reentry, with moderately increased +Gz (head-to-foot) acceleration and gravitational force, the microgravity "euhydration" becomes functional progressive dehydration contributing to the general reentry syndrome (GRS) which, upon landing the Shuttle, can and often results in gastrointestinal distress, disorientation, vertigo, fatigue, and fainting. Various pre-reentry hyperhydration procedures have been utilized to counteract the GRS. Thus, the somewhat decreased central venous pressure and lack of diuresis early in spaceflight suggests mechanisms other than the Gauer-Henry reflex are more important for maintaining fluid volume homeostasis in astronauts. Inflight hypohydration and hypovolemia are more important for maintaining fluid volume homeostasis in astronauts.

Greenleaf, John E.↗
NASA NTRS2004

Sub-Micrometer Scale Minor Element Mapping in Interplanetary Dust Particles: A Test for Stratospheric Contamination

Combined X-ray microprobe (XRM), energy dispersive x-ray fluorescence using a Transmission Electron Microscope (TEM), and electron microprobe measurements have determined that the average bulk chemical composition of the interplanetary dust particles (IDPs) collected from the Earth s stratosphere is enriched relative to the CI meteorite composition by a factor of 2 to 4 for carbon and for the moderately volatile elements Na, K, P, Mn, Cu, Zn, Ga, Ge, and Se, and enriched to approximately 30 times CI for Br. However, Jessberger et al., who have reported similar bulk enrichments using Proton Induced X-ray Emission (PIXE), attribute the enrichments to contamination by meteor-derived atmospheric aerosols during the several weeks these IDPs reside in the Earth s atmosphere prior to collection. Using scanning Auger spectroscopy, a very sensitive surface analysis technique, Mackinnon and Mogk have observed S contamination on the surface of IDPs, presumably due to the accretion of sulfate aerosols during stratospheric residence. But the S-rich layer they detected was so thin (approximately 100 angstroms thick) that the total amount of S on the surface was too small to significantly perturb the bulk S-content of a chondritic IDP. Stephan et al. provide support for the contamination hypothesis by reporting the enrichment of Br on the edges of the IDPs using Time-of-Flight Secondary-Ion Mass-Spectrometry (TOFSIMS), but TOF-SIMS is notorious for producing false edge-effects, particularly on irregularly-shaped samples like IDPs. Sutton et al. mapped the spatial distribution of Fe, Ni, Zn, Br, and Sr, at the approximately 2 m scale, in four IDPs using element-specific x-ray fluorescence (XRF) computed microtomography. They found the moderately volatile elements Zn and Br, although spatially inhomogeneous, were not concentrated on the surface of any of the IDPs they examined, suggesting that the Zn and the Br enrichments in the IDPs are not due to contamination during stratospheric residence.

Flynn, G. J.↗
NASA NTRS1999

Inactivity amplifies the catabolic response of skeletal muscle to cortisol

Severe injury or trauma is accompanied by both hypercortisolemia and prolonged inactivity or bed rest (BR). Trauma and BR alone each result in a loss of muscle nitrogen, albeit through different metabolic alterations. Although BR alone can result in a 2-3% loss of lean body mass, the effects of severe trauma can be 2- to 3-fold greater. We investigated the combined effects of hypercortisolemia and prolonged inactivity on muscle protein metabolism in healthy volunteers. Six males were studied before and after 14 days of strict BR using a model based on arteriovenous sampling and muscle biopsy. Fractional synthesis and breakdown rates of skeletal muscle protein were also directly calculated. Each assessment of protein metabolism was conducted during a 12-h infusion of hydrocortisone sodium succinate (120 microg/kg x h), resulting in blood cortisol concentrations that mimic severe injury (approximately 31 microg/dL). After 14 days of strict BR, hypercortisolemia increased phenylalanine efflux from muscle by 3-fold (P < 0.05). The augmented negative amino acid balance was the result of an increased muscle protein breakdown (P < 0.05) without a concomitant change in muscle protein synthesis. Muscle efflux of glutamine and alanine increased significantly after bed rest due to a significant increase in de novo synthesis (P < 0.05). Thus, inactivity sensitizes skeletal muscle to the catabolic effects of hypercortisolemia. Furthermore, these effects on healthy volunteers are analogous to those seen after severe injury.

Non-NASA Center↗
NASA NTRS1992

Effect of leg exercise training on vascular volumes during 30 days of 6 degrees head-down bed rest

Plasma and red cell volumes, body density, and water balance were measured in 19 men (32-42 yr) confined to bed rest (BR). One group (n = 5) had no exercise training (NOE), another near-maximal variable-intensity isotonic exercise for 60 min/day (ITE; n = 7), and the third near-maximal intermittent isokinetic exercise for 60 min/day (IKE; n = 7). Caloric intake was 2,678-2,840 kcal/day; mean body weight (n = 19) decreased by 0.58 +/- 0.35 (SE) kg during BR due to a negative fluid balance (diuresis) on day 1. Mean energy costs for the NOE, and IKE, and ITE regimens were 83 (3.6 +/- 0.2 ml O2.min-1.kg-1), 214 (8.9 +/- 0.5 ml.min-1.kg-1), and 446 kcal/h (18.8 +/- 1.6 ml.min-1.kg-1), respectively. Body densities within groups and mean urine volumes (1,752-1,846 ml/day) between groups were unchanged during BR. Resting changes in plasma volume (ml/kg) after BR were -1.5 +/- 2.3% (NS) in ITE, -14.7 +/- 2.8% (P less than 0.05) in NOE, and -16.8 +/- 2.9% (P less than 0.05) in IKE, and mean water balances during BR were +295, -106, and +169 ml/24 h, respectively. Changes in red cell volume followed changes in plasma volume. The significant chronic decreases in plasma volume in the IKE and NOE groups and its maintenance in the ITE group could not be accounted for by water balance or by responses of the plasma osmotic, protein, vasopressin, or aldosterone concentrations or plasma renin activity. There was close coupling between resting plasma volume and plasma protein and osmotic content.(ABSTRACT TRUNCATED AT 250 WORDS).

NASA Discipline Regulatory Physiology↗
NASA NTRS2010

Gender Differences in Isokinetic Strength after 60 and 90 d Bed Rest

Recent reports suggest that changes in muscle strength following disuse may differ between males and females. PURPOSE: To examine potential gender differences in strength changes following 60 and 90 d of experimental bed rest. METHODS: Isokinetic extensor and flexor strength of the knee (60deg and 180deg/s, concentric only), ankle (30deg/s, concentric and eccentric), and trunk (60deg/s, concentric only) were measured following 60 d (males: n=4, 34.5+/-9.6 y; females: n=4, 35.5+/-8.2 y) and 90 d (males: n=10, 31.4+/-4.8 y; females: n=5, 37.6+/-9.9 y) of 6-degree head-down-tilt bed rest (BR; N=23). Subjects were fed a controlled diet (55%/15%/ 30%, CHO/PRO/FAT) that maintained body weight within 3% of the weight recorded on Day 3 of bed rest. After a familiarization session, testing was conducted 6 d before BR and 2 d after BR completion. Peak torque and total work were calculated for the tests performed. To allow us to combine data from both 60- and 90-d subjects, we used a mixed-model statistical analysis in which time and gender were fixed effects and bed rest duration was a random effect. Log-transformations of strength measures were utilized when necessary in order to meet statistical assumptions. RESULTS: Main effects were seen for both time and gender (p<0.05), showing decreased strength in response to bed rest for both males and females, and males stronger than females for most strength measures. Only one interaction effect was observed: females exhibited a greater loss of trunk extensor peak torque at 60 d versus pre-BR, relative to males (p=0.004). CONCLUSION: Sixty and 90 d of BR induced significant losses in isokinetic muscle strength of the locomotor and postural muscles of the knee, ankle, and trunk. Although males were stronger than females for most of the strength measures that we examined, only changes in trunk extensor peak torque were greater for females than males at day 60 of bed rest

English, K. L.↗
DOE OSTI2020

Materials Data on Hg6S4Br3Cl by Materials Project

Hg6S4Br3Cl crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are four inequivalent Hg2+ sites. In the first Hg2+ site, Hg2+ is bonded in a 5-coordinate geometry to two S2-, two Br1-, and one Cl1- atom. Both Hg–S bond lengths are 2.46 Å. There are one shorter (3.14 Å) and one longer (3.54 Å) Hg–Br bond lengths. The Hg–Cl bond length is 2.84 Å. In the second Hg2+ site, Hg2+ is bonded to two equivalent S2- and three Br1- atoms to form distorted HgS2Br3 square pyramids that share corners with two equivalent HgS2Br4 octahedra, edges with two equivalent HgS2Br4 octahedra, and an edgeedge with one HgS2Br3 square pyramid. The corner-sharing octahedral tilt angles are 66°. Both Hg–S bond lengths are 2.46 Å. There are a spread of Hg–Br bond distances ranging from 2.97–3.29 Å. In the third Hg2+ site, Hg2+ is bonded in a 5-coordinate geometry to two equivalent S2-, two Br1-, and one Cl1- atom. Both Hg–S bond lengths are 2.45 Å. There are one shorter (3.34 Å) and one longer (3.39 Å) Hg–Br bond lengths. The Hg–Cl bond length is 2.83 Å. In the fourth Hg2+ site, Hg2+ is bonded to two S2- and four Br1- atoms to form distorted HgS2Br4 octahedra that share corners with four equivalent HgS2Br4 octahedra, a cornercorner with one HgS2Br3 square pyramid, edges with four equivalent HgS2Br4 octahedra, and an edgeedge with one HgS2Br3 square pyramid. The corner-sharing octahedra tilt angles range from 0–4°. Both Hg–S bond lengths are 2.44 Å. There are a spread of Hg–Br bond distances ranging from 3.20–3.48 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a 3-coordinate geometry to three Hg2+ atoms. In the second S2- site, S2- is bonded in a 3-coordinate geometry to three Hg2+ atoms. There are four inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a 6-coordinate geometry to six Hg2+ atoms. In the second Br1- site, Br1- is bonded in a square co-planar geometry to four equivalent Hg2+ atoms. In the third Br1- site, Br1- is bonded in a 7-coordinate geometry to five Hg2+ atoms. In the fourth Br1- site, Br1- is bonded in a distorted body-centered cubic geometry to eight Hg2+ atoms. Cl1- is bonded in a distorted trigonal planar geometry to three Hg2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Hg6S4IBr2Cl by Materials Project

Hg6S4IBr2Cl crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. there are four inequivalent Hg2+ sites. In the first Hg2+ site, Hg2+ is bonded in a 6-coordinate geometry to two S2-, two equivalent I1-, and two Br1- atoms. Both Hg–S bond lengths are 2.45 Å. There are one shorter (3.43 Å) and one longer (3.64 Å) Hg–I bond lengths. There are one shorter (3.15 Å) and one longer (3.35 Å) Hg–Br bond lengths. In the second Hg2+ site, Hg2+ is bonded in a distorted trigonal bipyramidal geometry to two equivalent S2-, two Br1-, and one Cl1- atom. Both Hg–S bond lengths are 2.50 Å. There are one shorter (3.27 Å) and one longer (3.39 Å) Hg–Br bond lengths. The Hg–Cl bond length is 2.62 Å. In the third Hg2+ site, Hg2+ is bonded in a 6-coordinate geometry to two S2-, two equivalent I1-, and two Br1- atoms. Both Hg–S bond lengths are 2.45 Å. There are one shorter (3.40 Å) and one longer (3.71 Å) Hg–I bond lengths. There are one shorter (3.16 Å) and one longer (3.30 Å) Hg–Br bond lengths. In the fourth Hg2+ site, Hg2+ is bonded in a 4-coordinate geometry to two equivalent S2-, two equivalent Br1-, and one Cl1- atom. Both Hg–S bond lengths are 2.48 Å. There are one shorter (3.20 Å) and one longer (3.64 Å) Hg–Br bond lengths. The Hg–Cl bond length is 2.67 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted trigonal non-coplanar geometry to three Hg2+ atoms. In the second S2- site, S2- is bonded in a distorted trigonal non-coplanar geometry to three Hg2+ atoms. I1- is bonded in a distorted body-centered cubic geometry to eight Hg2+ atoms. There are two inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a 5-coordinate geometry to five Hg2+ atoms. In the second Br1- site, Br1- is bonded in a 7-coordinate geometry to seven Hg2+ atoms. Cl1- is bonded in a water-like geometry to two Hg2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Tl3PbBr5 by Materials Project

Tl3PbBr5 crystallizes in the orthorhombic P2_12_12_1 space group. The structure is three-dimensional. there are three inequivalent Tl1+ sites. In the first Tl1+ site, Tl1+ is bonded in a 8-coordinate geometry to eight Br1- atoms. There are a spread of Tl–Br bond distances ranging from 3.25–3.76 Å. In the second Tl1+ site, Tl1+ is bonded to seven Br1- atoms to form distorted TlBr7 pentagonal bipyramids that share corners with four equivalent PbBr7 pentagonal bipyramids, an edgeedge with one PbBr7 pentagonal bipyramid, edges with two equivalent TlBr7 pentagonal bipyramids, and a faceface with one PbBr7 pentagonal bipyramid. There are a spread of Tl–Br bond distances ranging from 3.35–3.66 Å. In the third Tl1+ site, Tl1+ is bonded in a 8-coordinate geometry to eight Br1- atoms. There are a spread of Tl–Br bond distances ranging from 3.34–3.86 Å. Pb2+ is bonded to seven Br1- atoms to form PbBr7 pentagonal bipyramids that share corners with four equivalent TlBr7 pentagonal bipyramids, an edgeedge with one TlBr7 pentagonal bipyramid, edges with two equivalent PbBr7 pentagonal bipyramids, and a faceface with one TlBr7 pentagonal bipyramid. There are a spread of Pb–Br bond distances ranging from 2.96–3.38 Å. There are five inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a 6-coordinate geometry to five Tl1+ and one Pb2+ atom. In the second Br1- site, Br1- is bonded to five Tl1+ and one Pb2+ atom to form distorted BrTl5Pb pentagonal pyramids that share corners with five BrTl4Pb2 octahedra, corners with four equivalent BrTl5Pb pentagonal pyramids, edges with three BrTl4Pb2 octahedra, edges with three equivalent BrTl5Pb pentagonal pyramids, faces with two BrTl4Pb2 octahedra, and a faceface with one BrTl5Pb pentagonal pyramid. The corner-sharing octahedra tilt angles range from 34–73°. In the third Br1- site, Br1- is bonded to four Tl1+ and two equivalent Pb2+ atoms to form distorted BrTl4Pb2 octahedra that share corners with seven BrTl4Pb2 octahedra, corners with six BrTl5Pb pentagonal pyramids, edges with three BrTl5Pb pentagonal pyramids, faces with two equivalent BrTl4Pb2 octahedra, and faces with two BrTl5Pb pentagonal pyramids. The corner-sharing octahedra tilt angles range from 28–45°. In the fourth Br1- site, Br1- is bonded to four Tl1+ and two equivalent Pb2+ atoms to form distorted BrTl4Pb2 octahedra that share corners with seven BrTl4Pb2 octahedra, corners with six BrTl5Pb pentagonal pyramids, an edgeedge with one BrTl5Pb pentagonal pyramid, faces with two equivalent BrTl4Pb2 octahedra, and faces with three BrTl5Pb pentagonal pyramids. The corner-sharing octahedra tilt angles range from 28–44°. In the fifth Br1- site, Br1- is bonded to five Tl1+ and one Pb2+ atom to form distorted BrTl5Pb pentagonal pyramids that share corners with seven BrTl4Pb2 octahedra, corners with four equivalent BrTl5Pb pentagonal pyramids, an edgeedge with one BrTl4Pb2 octahedra, edges with three equivalent BrTl5Pb pentagonal pyramids, faces with three BrTl4Pb2 octahedra, and a faceface with one BrTl5Pb pentagonal pyramid. The corner-sharing octahedra tilt angles range from 30–46°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on H5BrO2 by Materials Project

(H2O)2HBr crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are five inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- and one Br1- atom. The H–O bond length is 0.99 Å. The H–Br bond length is 2.30 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- and one Br1- atom. The H–O bond length is 1.00 Å. The H–Br bond length is 2.26 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- and one Br1- atom. The H–O bond length is 1.01 Å. The H–Br bond length is 2.20 Å. In the fourth H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.16 Å) and one longer (1.26 Å) H–O bond length. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one O2- and one Br1- atom. The H–O bond length is 1.00 Å. The H–Br bond length is 2.27 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to three H1+ atoms. In the second O2- site, O2- is bonded in a trigonal non-coplanar geometry to three H1+ atoms. Br1- is bonded in a 4-coordinate geometry to four H1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Pb9(Br5O2)2 by Materials Project

Pb9(O2Br5)2 crystallizes in the tetragonal P4/n space group. The structure is three-dimensional. there are three inequivalent Pb2+ sites. In the first Pb2+ site, Pb2+ is bonded in a distorted square pyramidal geometry to five Br1- atoms. There are one shorter (2.77 Å) and four longer (3.11 Å) Pb–Br bond lengths. In the second Pb2+ site, Pb2+ is bonded in a 1-coordinate geometry to one O2- and six Br1- atoms. The Pb–O bond length is 2.30 Å. There are a spread of Pb–Br bond distances ranging from 2.91–3.82 Å. In the third Pb2+ site, Pb2+ is bonded in a 3-coordinate geometry to three equivalent O2- and two Br1- atoms. There are a spread of Pb–O bond distances ranging from 2.35–2.40 Å. There are one shorter (3.54 Å) and one longer (3.59 Å) Pb–Br bond lengths. O2- is bonded to four Pb2+ and one Br1- atom to form a mixture of distorted edge, face, and corner-sharing OPb4Br tetrahedra. The O–Br bond length is 3.57 Å. There are four inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a 1-coordinate geometry to five Pb2+ atoms. In the second Br1- site, Br1- is bonded in a 1-coordinate geometry to one Pb2+ atom. In the third Br1- site, Br1- is bonded in a 12-coordinate geometry to eight Pb2+ and four equivalent O2- atoms. In the fourth Br1- site, Br1- is bonded in a 2-coordinate geometry to five Pb2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on LiGaBr3 by Materials Project

LiGaBr3 crystallizes in the monoclinic P2_1/m space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to six Br1- atoms to form corner-sharing LiBr6 octahedra. The corner-sharing octahedra tilt angles range from 39–46°. There are a spread of Li–Br bond distances ranging from 2.72–2.97 Å. In the second Li1+ site, Li1+ is bonded to six Br1- atoms to form corner-sharing LiBr6 octahedra. The corner-sharing octahedra tilt angles range from 41–51°. There are a spread of Li–Br bond distances ranging from 2.82–2.94 Å. There are two inequivalent Ga2+ sites. In the first Ga2+ site, Ga2+ is bonded in a trigonal non-coplanar geometry to three Br1- atoms. There are one shorter (2.43 Å) and two longer (2.44 Å) Ga–Br bond lengths. In the second Ga2+ site, Ga2+ is bonded in a trigonal non-coplanar geometry to three Br1- atoms. There are one shorter (2.42 Å) and two longer (2.43 Å) Ga–Br bond lengths. There are four inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a distorted T-shaped geometry to two Li1+ and one Ga2+ atom. In the second Br1- site, Br1- is bonded in a distorted trigonal non-coplanar geometry to two equivalent Li1+ and one Ga2+ atom. In the third Br1- site, Br1- is bonded in a distorted trigonal planar geometry to two Li1+ and one Ga2+ atom. In the fourth Br1- site, Br1- is bonded in a distorted T-shaped geometry to two equivalent Li1+ and one Ga2+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KInBr3 by Materials Project

KInBr3 crystallizes in the trigonal P-3 space group. The structure is two-dimensional and consists of one KInBr3 sheet oriented in the (0, 0, 1) direction. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a distorted q6 geometry to nine Br1- atoms. There are a spread of K–Br bond distances ranging from 3.55–3.63 Å. In the second K1+ site, K1+ is bonded in a distorted octahedral geometry to six Br1- atoms. All K–Br bond lengths are 3.39 Å. There are two inequivalent In2+ sites. In the first In2+ site, In2+ is bonded in a distorted T-shaped geometry to three equivalent Br1- atoms. All In–Br bond lengths are 2.64 Å. In the second In2+ site, In2+ is bonded in a distorted T-shaped geometry to three equivalent Br1- atoms. All In–Br bond lengths are 2.63 Å. There are two inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a 4-coordinate geometry to three K1+ and one In2+ atom. In the second Br1- site, Br1- is bonded in a 3-coordinate geometry to two K1+ and one In2+ atom.

36 MATERIALS SCIENCE↗