Sm-Nd and Rb-Sr systematics in volcanics and ultramafic xenoliths from Malaita, Solomon Islands, and the nature of the Ontong Java Plateau
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Bielski-Zyskind, M.↗
SEARCH · Engineering Papers
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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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A miniature tactical Rb frequency standard
Work on an innovative design for miniature rubidium frequency standards has reached the pre-production demonstration stage at Litton Guidance and Control Systems. Pre-production units were built and tested under contract to the Rome Air Development Center of the U.S. Air Force Systems Command. The units, which are designed for use in tactical military applications, feature fast warm-up, low power consumption, and vibration insensitivity. The output stability under vibration is maintained without the need for external shock-mounts. The design objectives and test results are discussed.
Kwon, T. M.↗
Transitions of the type 2s-2p in fluorinelike and oxygenlike As, Se, Br, and Rb
Transitions of the type 2s-2p in the F I and O I isoelectronic sequences of arsenic, selenium, bromine, and rubidium have been identified in spectra from laser-produced plasmas. Wavelengths in the range 50 to 90 A were measured to an accuracy of 0.01 A or better. The wavelengths of the magnetic-dipole transitions within the ground configurations are predicted.
Feldman, U.↗
The Rb 780-nanometer Faraday anomalous dispersion optical filter: Theory and experiment
The Faraday anomalous dispersion optical filter may provide ultra-high background noise rejection for free-space laser communications systems. The theoretical model for the filter is reported. The experimental measurements and their comparison with theoretical results are discussed. The results show that the filter can provide a 56-dB solar background noise rejection with about a 2-GHz transmission bandwidth and no image degradation. To further increase the background noise rejection, a composite Zeeman and Faraday anomalous dispersion optical filter is designed and experimentally demonstrated.
Yin, B.↗
Results of a Cyclic Load Test of an RB-47E Airplane
Results of a cyclic load test made by NASA on an EB-47E airplane are given. The test reported on is for one of three B-47 airplanes in a test program set up by the U. S. Air Force to evaluate the effect of wing structural reinforcements on fatigue life. As a result of crack development in the upper fuselage longerons of the other two airplanes in the program, a longeron and fuselage skin modification was incorporated early in the test. Fuselage strain-gage measurements made before and after the longeron modification and wing strain-gage measurements made only after wing reinforcement are summarized. The history of crack development and repair is given in detail. Testing was terminated one sequence short of the planned end of the program with the occurrence of a major crack in the lower right wing skin.
Huston, Wilber B.↗
Review of MSFC SBIR's: Xinetics RB-SiC Mirror Fabrication Study, UltraMet PG Foam Mirror Fabrication Study, Blue Line Eng. AI Enhanced Edge Sensors and Fully Active Subscale Telescope
This presentation will briefly review the objectives and anticipated benefits of several Small Business Innovative Research projects in progress under the direction of Marshall Space Flight Center. They all relate to the development of advanced optical systems technologies important to future astronomical missions in space.
Montgomery, Edward E., IV↗
Rb-Sr and Sm-Nd Isotope Systematics of Shergottite NWA 856: Crystallization Age and Implications for Alteration of Hot Desert SNC Meteorites
Nakhlite NWA 998 was discovered in Algeria in 2001, and is unique among the six known members of this group of Martian meteorites in containing significant modal orthopyroxene. Initial petrologic and isotopic data were reported by Irving et al. This 456 gram stone consists mainly of sub-calcic augite with subordinate olivine and minor orthopyroxene, titanomagnetite, pyrrhotite, chlorapatite, and intercumulus An(sub 35) plagioclase. We report here preliminary results of radiogenic isotopic analyses conducted on fragmental material from the main mass.
Brandon, A. D.↗
Three-System Isotopic of Lunar Norite 78238: Rb-Sr Results
The duration of lunar magma ocean (LMO) crystallization is poorly constrained (Fig. 1). Three techniques employed to determine the age of LMO solidification are 1) dating ferroan anorthosites (FANs), thought to be primary cumulates from the LMO, 2) calculating model ages for KREEP, the most incompatible element enriched material that remained after approx.99.5% of the LMO crystallized [1], and 3) constraining the age of the oldest KREEP-rich magnesium suite (Mg-suite) or alkali suite rock. Dating FANs is difficult because the samples are essentially monomineralic and contain low abundances of many elements used in isotopic dating. In addition, the young ages determined for some FANs may be related to impact metamorphism, potentially making FANs non-ideal for dating the age of LMO crystallization (e.g., [2]). Model ages for KREEP formation are dependent on the assumptions of the initial isotopic composition and parent/daughter ratio of the source. However, lunar rocks are susceptible to isotopic resetting and volatile element loss during shock, and are therefore unlikely to yield consistent model LMO crystallization ages (e.g., [3]). Rocks from the Mg-suite contain KREEP, indicating that they formed after LMO crystallization, and have old ages that indicate they formed almost immediately after the LMO crystallized (Fig. 1). Therefore, precisely dating the oldest Mg-suite rock is a promising way to constrain the age of LMO solidification.
Edmundson, J.↗
Effect of EMIC Wave Normal Angle Distribution on Relativistic Electron Scattering in Outer RB
We present the equatorial and bounce average pitch angle diffusion coefficients for scattering of relativistic electrons by the H+ mode of EMIC waves. Both the model (prescribed) and self consistent distributions over the wave normal angle are considered. The main results of our calculation can be summarized as follows: First, in comparison with field aligned waves, the intermediate and highly oblique waves reduce the pitch angle range subject to diffusion, and strongly suppress the scattering rate for low energy electrons (E less than 2 MeV). Second, for electron energies greater than 5 MeV, the |n| = 1 resonances operate only in a narrow region at large pitch-angles, and despite their greatest contribution in case of field aligned waves, cannot cause electron diffusion into the loss cone. For those energies, oblique waves at |n| greater than 1 resonances are more effective, extending the range of pitch angle diffusion down to the loss cone boundary, and increasing diffusion at small pitch angles by orders of magnitude.
Khazanov, G. V.↗
Rb-Sr and Sm-Nd Ages of Zagami DML and SR Isotopic Heterogeneity in Zagami
Zagami contains lithologic heterogeneity suggesting that it did not form in a homogeneous, thick lava flow [1]. We have previously investigated the Sr and Nd isotopic systematics of Coarse-Grained (CG) and Fine-Grained (FG) lithologies described by [2]. Both appear to belong to Normal Zagami (NZ) [1,3], but their initial Sr-isotopic compositions differ [4,5]. Here we report new analyses of the Dark Mottled Lithology (DML, [3]) that show its age and initial Sr and Nd isotopic compositions to be identical within error limits with those of CG, but Sr initial isotopic compositions differ from those of FG.
Nyquist, L.aurenceE.↗
Rb-Sr Isotopic Systematics of Alkalai-Rich Fragments in Yamato-74442 and Bhola
We have undertaken Rb.Sr isotopic studies on alkali-rich fragments in Bhola and Y-74442 to precisely deter-mine their crystallization ages and isotopic signatures of their precursor material(s).
Yokoyama, T.↗
Standards for Analysis of Ce, La, Pb, Rb, Se, Sr, Y, AND Zr in Rock Samples Using Laser-induced Breakdown Spectroscopy and X-ray Fluorescence
Analytical geochemistry has long depended on the availability of robust suites of rock standards with well-characterized compositions. Standard rock powders for wet chemistry and x-ray fluorescence were initially characterized and supplied to the community by the U.S. Geological Survey, which continues to distribute a few dozen standards. Many other rock standards have subsequently been developed by organizations such as the Centre de Recherches Pétrographiques et Géochimiques (CRPG) and Brammer Standard Company, Inc.
LIBS↗
Distribution of Alkalis (Na, Cs, Rb) Between Silicate and Sulfide: Implications for Planetary Volatile Depletion
The abundances of volatile elements in the Earth's mantle are correlated with their temperatures of condensation. This depletion can be due to either incomplete condensation of the elements during the nebula condensation or evaporation processes during planetary growth. Elements that have affinities with metals (siderophile) and sulfides (chalcophile) are additionally depleted due to their segregation into the core. Therefore, study of lithophile elements could be useful to isolate processes of volatilization and their effect on the abundance of the elements in the Earth's mantle. However, the correlation of these lithophile elements including alkali elements, with their temperatures of condensation shows a significant scatter, which is difficult to reconcile with a depletion by vaporization or incomplete condensation alone.
Boujibar, A.↗
Radiation Belt Daily Average Electron Flux Model (RB‐Daily‐E) From the Seven‐Year Van Allen Probes Mission and Its Application to Interpret GPS On‐Orbit Solar Array Degradation
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Christine Gabrielse↗
Chromatography purification of Rb for accurate isotopic analysis by MC-ICPMS: a comparison between AMP-PAN, cation-exchange, and Sr resins
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Nicole X. Nie↗
Materials Data on Rb16Sn16F47 by Materials Project
Rb16Sn16F47 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are sixteen inequivalent Rb sites. In the first Rb site, Rb is bonded in a 7-coordinate geometry to seven F atoms. There are a spread of Rb–F bond distances ranging from 2.82–2.91 Å. In the second Rb site, Rb is bonded in a 9-coordinate geometry to nine F atoms. There are a spread of Rb–F bond distances ranging from 2.87–3.24 Å. In the third Rb site, Rb is bonded in a 9-coordinate geometry to nine F atoms. There are a spread of Rb–F bond distances ranging from 2.88–3.26 Å. In the fourth Rb site, Rb is bonded in a 7-coordinate geometry to eight F atoms. There are a spread of Rb–F bond distances ranging from 2.82–3.37 Å. In the fifth Rb site, Rb is bonded in a 7-coordinate geometry to seven F atoms. There are a spread of Rb–F bond distances ranging from 2.77–3.32 Å. In the sixth Rb site, Rb is bonded in a 9-coordinate geometry to nine F atoms. There are a spread of Rb–F bond distances ranging from 2.86–3.22 Å. In the seventh Rb site, Rb is bonded in a 9-coordinate geometry to nine F atoms. There are a spread of Rb–F bond distances ranging from 2.82–3.22 Å. In the eighth Rb site, Rb is bonded in a 7-coordinate geometry to seven F atoms. There are a spread of Rb–F bond distances ranging from 2.78–2.91 Å. In the ninth Rb site, Rb is bonded in a 7-coordinate geometry to seven F atoms. There are a spread of Rb–F bond distances ranging from 2.77–2.91 Å. In the tenth Rb site, Rb is bonded in a 9-coordinate geometry to nine F atoms. There are a spread of Rb–F bond distances ranging from 2.82–3.17 Å. In the eleventh Rb site, Rb is bonded in a 9-coordinate geometry to nine F atoms. There are a spread of Rb–F bond distances ranging from 2.85–3.21 Å. In the twelfth Rb site, Rb is bonded in a 7-coordinate geometry to seven F atoms. There are a spread of Rb–F bond distances ranging from 2.78–3.31 Å. In the thirteenth Rb site, Rb is bonded in a 7-coordinate geometry to seven F atoms. There are a spread of Rb–F bond distances ranging from 2.79–2.89 Å. In the fourteenth Rb site, Rb is bonded in a 9-coordinate geometry to nine F atoms. There are a spread of Rb–F bond distances ranging from 2.82–3.22 Å. In the fifteenth Rb site, Rb is bonded in a 9-coordinate geometry to nine F atoms. There are a spread of Rb–F bond distances ranging from 2.88–3.21 Å. In the sixteenth Rb site, Rb is bonded in a 7-coordinate geometry to seven F atoms. There are a spread of Rb–F bond distances ranging from 2.80–2.95 Å. There are sixteen inequivalent Sn sites. In the first Sn site, Sn is bonded in a distorted rectangular see-saw-like geometry to four F atoms. There are a spread of Sn–F bond distances ranging from 2.09–2.30 Å. In the second Sn site, Sn is bonded in a distorted T-shaped geometry to three F atoms. There are a spread of Sn–F bond distances ranging from 2.10–2.41 Å. In the third Sn site, Sn is bonded in a distorted rectangular see-saw-like geometry to four F atoms. There are a spread of Sn–F bond distances ranging from 2.07–2.35 Å. In the fourth Sn site, Sn is bonded in a distorted rectangular see-saw-like geometry to four F atoms. There are a spread of Sn–F bond distances ranging from 2.09–2.31 Å. In the fifth Sn site, Sn is bonded in a distorted rectangular see-saw-like geometry to four F atoms. There are a spread of Sn–F bond distances ranging from 2.09–2.31 Å. In the sixth Sn site, Sn is bonded in a distorted rectangular see-saw-like geometry to four F atoms. There are a spread of Sn–F bond distances ranging from 2.08–2.41 Å. In the seventh Sn site, Sn is bonded in a rectangular see-saw-like geometry to four F atoms. There are a spread of Sn–F bond distances ranging from 2.05–2.31 Å. In the eighth Sn site, Sn is bonded in a distorted rectangular see-saw-like geometry to four F atoms. There are a spread of Sn–F bond distances ranging from 2.09–2.27 Å. In the ninth Sn site, Sn is bonded in a distorted rectangular see-saw-like geometry to four F atoms. There are a spread of Sn–F bond distances ranging from 2.09–2.28 Å. In the tenth Sn site, Sn is bonded in a rectangular see-saw-like geometry to four F atoms. There are a spread of Sn–F bond distances ranging from 2.05–2.32 Å. In the eleventh Sn site, Sn is bonded in a distorted rectangular see-saw-like geometry to four F atoms. There are a spread of Sn–F bond distances ranging from 2.08–2.35 Å. In the twelfth Sn site, Sn is bonded in a distorted rectangular see-saw-like geometry to four F atoms. There are a spread of Sn–F bond distances ranging from 2.10–2.29 Å. In the thirteenth Sn site, Sn is bonded in a distorted rectangular see-saw-like geometry to four F atoms. There are a spread of Sn–F bond distances ranging from 2.09–2.29 Å. In the fourteenth Sn site, Sn is bonded in a distorted rectangular see-saw-like geometry to four F atoms. There are a spread of Sn–F bond distances ranging from 2.08–2.35 Å. In the fifteenth Sn site, Sn is bonded in a distorted rectangular see-saw-like geometry to four F atoms. There are a spread of Sn–F bond distances ranging from 2.05–2.34 Å. In the sixteenth Sn site, Sn is bonded in a distorted rectangular see-saw-like geometry to four F atoms. There are a spread of Sn–F bond distances ranging from 2.10–2.30 Å. There are forty-seven inequivalent F sites. In the first F site, F is bonded in a 1-coordinate geometry to three Rb and one Sn atom. In the second F site, F is bonded to two Rb and two Sn atoms to form distorted FRb2Sn2 trigonal pyramids that share corners with two FRb3Sn tetrahedra, a cornercorner with one FRb2Sn2 trigonal pyramid, and an edgeedge with one FRb3Sn tetrahedra. In the third F site, F is bonded in a 4-coordinate geometry to two Rb and two Sn atoms. In the fourth F site, F is bonded in a 4-coordinate geometry to three Rb and one Sn atom. In the fifth F site, F is bonded to three Rb and one Sn atom to form distorted FRb3Sn tetrahedra that share corners with three FRb3Sn tetrahedra and corners with two FRb2Sn2 trigonal pyramids. In the sixth F site, F is bonded in a 1-coordinate geometry to four Rb and one Sn atom. In the seventh F site, F is bonded to three Rb and one Sn atom to form distorted FRb3Sn tetrahedra that share a cornercorner with one FRb3Sn tetrahedra and corners with two FRb2Sn2 trigonal pyramids. In the eighth F site, F is bonded in a 4-coordinate geometry to three Rb and one Sn atom. In the ninth F site, F is bonded in a 4-coordinate geometry to two Rb and two Sn atoms. In the tenth F site, F is bonded in a 4-coordinate geometry to three Rb and one Sn atom. In the eleventh F site, F is bonded to two Rb and two Sn atoms to form distorted FRb2Sn2 trigonal pyramids that share corners with four FRb3Sn tetrahedra and a cornercorner with one FRb2Sn2 trigonal pyramid. In the twelfth F site, F is bonded in a distorted rectangular see-saw-like geometry to two Rb and two Sn atoms. In the thirteenth F site, F is bonded in a 1-coordinate geometry to three Rb and one Sn atom. In the fourteenth F site, F is bonded in a 4-coordinate geometry to two Rb and two Sn atoms. In the fifteenth F site, F is bonded in a 3-coordinate geometry to two Rb and one Sn atom. In the sixteenth F site, F is bonded in a 4-coordinate geometry to three Rb and one Sn atom. In the seventeenth F site, F is bonded to three Rb and one Sn atom to form distorted FRb3Sn tetrahedra that share corners with three FRb3Sn tetrahedra, a cornercorner with one FRb2Sn2 trigonal pyramid, and edges with two FRb2Sn2 tetrahedra. In the eighteenth F site, F is bonded in a 1-coordinate geometry to four Rb and one Sn atom. In the nineteenth F site, F is bonded in a 4-coordinate geometry to three Rb and one Sn atom. In the twentieth F site, F is bonded to three Rb and one Sn atom to form distorted FRb3Sn tetrahedra that share corners with two FRb3Sn tetrahedra and edges with three FRb2Sn2 tetrahedra. In the twenty-first F site, F is bonded in a distorted rectangular see-saw-like geometry to two Rb and two Sn atoms. In the twenty-second F site, F is bonded in a 5-coordinate geometry to four Rb and one Sn atom. In the twenty-third F site, F is bonded to two Rb and two Sn atoms to form distorted FRb2Sn2 tetrahedra that share corners with three FRb2Sn2 tetrahedra and edges with two FRb3Sn tetrahedra. In the twenty-fourth F site, F is bonded to two Rb and two Sn atoms to form distorted FRb2Sn2 tetrahedra that share corners with two FRb3Sn tetrahedra, a cornercorner with one FRb2Sn2 trigonal pyramid, and edges with two FRb3Sn tetrahedra. In the twenty-fifth F site, F is bonded in a 5-coordinate geometry to four Rb and one Sn atom. In the twenty-sixth F site, F is bonded in a distorted rectangular see-saw-like geometry to two Rb and two Sn atoms. In the twenty-seventh F site, F is bonded to three Rb and one Sn atom to form distorted FRb3Sn tetrahedra that share corners with two FRb2Sn2 tetrahedra and edges with three FRb3Sn tetrahedra. In the twenty-eighth F site, F is bonded in a 4-coordinate geometry to three Rb and one Sn atom. In the twenty-ninth F site, F is bonded in a 1-coordinate geometry to four Rb and one Sn atom. In the thirtieth F site, F is bonded to three Rb and one Sn atom to form distorted FRb3Sn tetrahedra that share corners with three FRb2Sn2 tetrahedra and edges with two FRb3Sn tetrahedra. In the thirty-first F site, F is bonded in a 4-coordinate geometry to three Rb and one Sn atom. In the thirty-second F site, F is bonded in a 3-coordinate geometry to two Rb and one Sn atom. In the thirty-third F site, F is bonded in a 4-coordinate geometry to two Rb and two Sn atoms. In the thirty-fourth F site, F is bonded in a 1-coordinate geometry to three Rb and one Sn atom. In the thirty-fifth F site, F is bonded in a distorted rectangular see-saw-like geometry to two Rb and two Sn atoms. In the thirty-sixth F site, F is bonded to two Rb and two Sn atoms to form distorted corner-sharing FRb2Sn2 tetrahedra. In the thirty-seventh F site, F is bonded in a 4-coordinate geometry to three Rb and one Sn atom. In the thirty-eighth F site, F is bonded in a 4-coordinate geometry to two Rb and two Sn atoms. In the thirty-ninth F site, F is bonded in a 4-coordinate geometry to three Rb and one Sn atom. In the fortieth F site, F is bonded to three Rb and one Sn atom to form a mixture of distorted corner and edge-sharing FRb3Sn tetrahedra. In the forty-first F site, F is bonded in a 1-coordinate geometry to four Rb and one Sn atom. In the forty-second F site, F is bonded in a 4-coordinate geometry to three Rb and one Sn atom. In the forty-third F site, F is bonded in a 4-coordinate geometry to three Rb and one Sn atom. In the forty-fourth F site, F is bonded in a 3-coordinate geometry to two Rb and one Sn atom. In the forty-fifth F site, F is bonded in a 4-coordinate geometry to two Rb and two Sn atoms. In the forty-sixth F site, F is bonded in a distorted rectangular see-saw-like geometry to two Rb and two Sn atoms. In the forty-seventh F site, F is bonded in a 1-coordinate geometry to four Rb and one Sn atom.
36 MATERIALS SCIENCE↗
Materials Data on Rb11Al14Si10(AgO16)3 by Materials Project
Rb11Al14Si10(AgO16)3 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are eleven inequivalent Rb sites. In the first Rb site, Rb is bonded in a 6-coordinate geometry to six O atoms. There are a spread of Rb–O bond distances ranging from 2.71–3.38 Å. In the second Rb site, Rb is bonded in a 2-coordinate geometry to two Ag and two O atoms. There are one shorter (4.20 Å) and one longer (4.24 Å) Rb–Ag bond lengths. There are one shorter (3.07 Å) and one longer (3.16 Å) Rb–O bond lengths. In the third Rb site, Rb is bonded in a T-shaped geometry to three O atoms. There are a spread of Rb–O bond distances ranging from 3.01–3.30 Å. In the fourth Rb site, Rb is bonded in a 1-coordinate geometry to one Ag and five O atoms. The Rb–Ag bond length is 4.21 Å. There are a spread of Rb–O bond distances ranging from 2.71–3.35 Å. In the fifth Rb site, Rb is bonded in a 3-coordinate geometry to five O atoms. There are a spread of Rb–O bond distances ranging from 2.67–3.21 Å. In the sixth Rb site, Rb is bonded in a 1-coordinate geometry to two Ag and five O atoms. There are one shorter (3.96 Å) and one longer (4.21 Å) Rb–Ag bond lengths. There are a spread of Rb–O bond distances ranging from 2.71–3.27 Å. In the seventh Rb site, Rb is bonded in a 1-coordinate geometry to two Ag and two O atoms. There are one shorter (3.95 Å) and one longer (4.11 Å) Rb–Ag bond lengths. There are one shorter (2.71 Å) and one longer (3.07 Å) Rb–O bond lengths. In the eighth Rb site, Rb is bonded in a 4-coordinate geometry to four O atoms. There are a spread of Rb–O bond distances ranging from 2.70–3.12 Å. In the ninth Rb site, Rb is bonded in a 4-coordinate geometry to four O atoms. There are a spread of Rb–O bond distances ranging from 2.71–3.13 Å. In the tenth Rb site, Rb is bonded in a 2-coordinate geometry to two O atoms. There are one shorter (2.65 Å) and one longer (2.74 Å) Rb–O bond lengths. In the eleventh Rb site, Rb is bonded in a 4-coordinate geometry to four O atoms. There are a spread of Rb–O bond distances ranging from 2.99–3.48 Å. There are three inequivalent Ag sites. In the first Ag site, Ag is bonded in a 3-coordinate geometry to two Rb and one Ag atom. The Ag–Ag bond length is 2.63 Å. In the second Ag site, Ag is bonded in a distorted trigonal pyramidal geometry to three Rb and one Ag atom. The Ag–Ag bond length is 2.63 Å. In the third Ag site, Ag is bonded in a 4-coordinate geometry to two Rb and two Ag atoms. There are fourteen inequivalent Al sites. In the first Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share a cornercorner with one AlO4 tetrahedra and corners with three SiO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.71–1.79 Å. In the second Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share a cornercorner with one SiO4 tetrahedra and corners with three AlO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.73–1.78 Å. In the third Al site, Al is bonded to four O atoms to form corner-sharing AlO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.72–1.77 Å. In the fourth Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share a cornercorner with one SiO4 tetrahedra and corners with three AlO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.74–1.77 Å. In the fifth Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share a cornercorner with one SiO4 tetrahedra and corners with three AlO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.74–1.78 Å. In the sixth Al site, Al is bonded to four O atoms to form corner-sharing AlO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.74–1.77 Å. In the seventh Al site, Al is bonded to four O atoms to form corner-sharing AlO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.73–1.75 Å. In the eighth Al site, Al is bonded to four O atoms to form corner-sharing AlO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.72–1.76 Å. In the ninth Al site, Al is bonded to four O atoms to form corner-sharing AlO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.74–1.77 Å. In the tenth Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share corners with two AlO4 tetrahedra and corners with two SiO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.70–1.82 Å. In the eleventh Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share a cornercorner with one SiO4 tetrahedra and corners with three AlO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.72–1.83 Å. In the twelfth Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share corners with two AlO4 tetrahedra and corners with two SiO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.71–1.83 Å. In the thirteenth Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share corners with two AlO4 tetrahedra and corners with two SiO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.71–1.81 Å. In the fourteenth Al site, Al is bonded to four O atoms to form AlO4 tetrahedra that share a cornercorner with one AlO4 tetrahedra and corners with three SiO4 tetrahedra. There are a spread of Al–O bond distances ranging from 1.75–1.78 Å. There are ten inequivalent Si sites. In the first Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two AlO4 tetrahedra and corners with two SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.60–1.67 Å. In the second Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two AlO4 tetrahedra and corners with two SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.59–1.66 Å. In the third Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one AlO4 tetrahedra and corners with three SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.60–1.68 Å. In the fourth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one AlO4 tetrahedra and corners with three SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.62–1.67 Å. In the fifth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one AlO4 tetrahedra and corners with three SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.61–1.66 Å. In the sixth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two AlO4 tetrahedra and corners with two SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.60–1.69 Å. In the seventh Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two AlO4 tetrahedra and corners with two SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.60–1.67 Å. In the eighth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share a cornercorner with one AlO4 tetrahedra and corners with three SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.62–1.67 Å. In the ninth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two AlO4 tetrahedra and corners with two SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.62–1.66 Å. In the tenth Si site, Si is bonded to four O atoms to form SiO4 tetrahedra that share corners with two AlO4 tetrahedra and corners with two SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.62–1.66 Å. There are forty-eight inequivalent O sites. In the first O site, O is bonded in a distorted bent 150 degrees geometry to one Rb and two Si atoms. In the second O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the third O site, O is bonded in a linear geometry to two Si atoms. In the fourth O site, O is bonded in a 2-coordinate geometry to one Rb, one Al, and one Si atom. In the fifth O site, O is bonded in a distorted bent 150 degrees geometry to one Rb, one Al, and one Si atom. In the sixth O site, O is bonded in a distorted bent 150 degrees geometry to one Rb and two Si atoms. In the seventh O site, O is bonded in a distorted bent 150 degrees geometry to one Rb, one Al, and one Si atom. In the eighth O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the ninth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the tenth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the eleventh O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the twelfth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the thirteenth O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the fourteenth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the fifteenth O site, O is bonded in a distorted bent 150 degrees geometry to one Al and one Si atom. In the sixteenth O site, O is bonded in a distorted bent 150 degrees geometry to one Rb and two Al atoms. In the seventeenth O site, O is bonded in a bent 150 degrees geometry to one Al and one Si atom. In the eighteenth O site, O is bonded in a linear geometry to one Al and one Si atom. In the nineteenth O site, O is bonded in a distorted linear geometry to one Rb, one Al, and one Si atom. In the twentieth O site, O is bonded in a distorted bent 150 degrees geometry to one Rb and two Al atoms. In the twenty-first O site, O is bonded in a bent 150 degrees geometry to two Al atoms. In the twenty-second O site, O is bonded in a bent 150 degrees geometry to two Al atoms. In the twenty-third O site, O is bonded in a bent 150 degrees geometry to two Al atoms. In the twenty-fourth O site, O is bonded in a distorted bent 120 degrees geometry to one Rb and two Al atoms. In the twenty-fifth O site, O is bonded in a distorted bent 120 degrees geometry to one Rb and two Al atoms. In the twenty-sixth O site, O is bonded in a distorted trigonal planar geometry to one Rb and two Al atoms. In the twenty-seventh O site, O is bonded in a distorted trigonal planar geometry to one Rb and two Al atoms. In the twenty-eighth O site, O is bonded in a distorted bent 150 degrees geometry to one Rb and two Al atoms. In the twenty-ninth O site, O is bonded in a distorted bent 150 degrees geometry to two Rb and two Al atoms. In the thirtieth O site, O is bonded in a distorted bent 150 degrees geometry to two Rb and two Al atoms. In the thirty-first O site, O is bonded in a 2-coordinate geometry to one Rb and two Al atoms. In the thirty-second O site, O is bonded in a distorted linear geometry to one Rb and two Al atoms. In the thirty-third O site, O is bonded in a distorted linear geometry to three Rb and two Al atoms. In the thirty-fourth O site, O is bonded in a linear geometry to one Rb and two Al atoms. In the thirty-fifth O site, O is bonded in a distorted linear geometry to three Rb and two Al atoms. In the thirty-sixth O site, O is bonded in a distorted bent 120 degrees geometry to two Al atoms. In the thirty-seventh O site, O is bonded in a 2-coordinate geometry to one Rb and two Al atoms. In the thirty-eighth O site, O is bonded in a distorted bent 150 degrees geometry to one Rb, one Al, and one Si atom. In the thirty-ninth O site, O is bonded in a distorted bent 150 degrees geometry to one Rb, one Al, and one Si atom. In the fortieth O site, O is bonded in a 2-coordinate geometry to two Rb, one Al, and one Si atom. In the forty-first O site, O is bonded in a 2-coordinate geometry to two Rb, one Al, and one Si atom. In the forty-second O site, O is bonded in a distorted bent 150 degrees geometry to two Rb, one Al, and one Si atom. In the forty-third O site, O is bonded in a distorted bent 150
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