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All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Composition-Dependent Photoluminescence Properties and Anti-Counterfeiting Applications of A 2 AgX 3 (A = Rb, Cs; X = Cl, Br, I)

Copper(I) halides are emerging as attractive alternatives to lead halide perovskites for optical and electronic applications. However, blue-emitting all-inorganic copper(I) halides suffer from poor stability and lack of tunability of their photoluminescence (PL) properties. In this work, the preparation of silver(I) halides A 2 AgX 3 (A = Rb, Cs; X = Cl, Br, I) through solid-state synthesis is reported. In contrast to the Cu(I) analogs, A 2 AgX 3 are broad-band emitters sensitive to A and X site substitutions. First-principle calculations show that defect-bound excitons are responsible for the observed main PL peaks in Rb 2 AgX 3 and that self-trapped excitons (STEs) contribute to a minor PL peak in Rb 2 AgBr 3 . This is in sharp contrast to Rb 2 CuX 3 , in which the PL is dominated by the emission by STEs. Moreover, the replacement of Cu(I) with Ag(I) in A 2 AgX 3 significantly improves photostability and stability in the air under ambient conditions, which enables their consideration for practical applications. Thus, luminescent inks based on A 2 AgX 3 are prepared and successfully used in anti-counterfeiting applications. The excellent light emission properties, significantly improved stability, simple preparation method, and tunable light emission properties demonstrated by A 2 AgX 3 suggest that silver(I) halides may be attractive alternatives to toxic lead halide perovskites and unstable copper(I) halides for optical applications.

36 MATERIALS SCIENCE↗
DOE OSTI2022

All-Inorganic Open-Framework Chalcogenides, A 3 Ga 5 S 9 · x H 2 O ( A = Rb and Cs), Exhibiting Ultrafast Uranyl Remediation and Illustrating a Novel Post-Synthetic Preparation of Open-Framework Oxychalcogenides

Fast and effective uranyl sequestration is of interest to the nuclear industry. Recently layered chalcogenide materials have demonstrated fast, selective, and efficient sorption properties towards uranyl cations and the development and investigation of new types of chalcogenide materials continues to be of interest and represents an intriguing option for uranyl remediation. Three new all-inorganic A 3 Ga 5 S 9 ·xH 2 O (A = Rb, Rb/Cs, and Cs) open-framework chalcogenides were obtained via an in-situ alkali carbonate to alkali sulfide conversion process achieved under mild hydrothermal conditions. The structures of the all-inorganic open framework chalcogenides consist of a 2-fold interpenetrated diamond-like 3D framework containing pseudo-T 3 [Ga 10 S 20 ] 10– supertetrahedra. 48% of the structural volume is occupied by A + cations and water species, as established by single-crystal X-ray diffraction (SCXRD), infrared (IR) and energy-dispersive (EDS) spectroscopies. The dynamic nature of the A + cations and water molecules within the pores was investigated via single crystal X-ray diffraction as well as by IR spectroscopy monitored H 2 O to D 2 O exchange experiments. Framework stability was probed with post-synthetic treatment of A 3 Ga 5 S 9 ·xH 2 O (A = Rb and Cs) samples in acidic solutions that resulted in the formation of the oxysulfide (A/H) 3 Ga 5 S 9–y O y ·xH 2 O (A = Rb and Cs; y = 0–1), as shown by SCXRD and IR. Ion-exchange studies on A 3 Ga 5 S 9 ·xH 2 O (A = Rb and Cs) samples were carried out utilizing a uranyl acetate solution. The presence of the UO 2 2+ species in the ion-exchanged product was supported by IR and EDS spectroscopies. Batch method ion-exchange experiments on Cs 3 Ga 5 S 9 ·xH 2 O powder demonstrated fast kinetics with 95% uranyl removal from the uranyl acetate solution during the first minute, a maximum uranyl uptake capacity of 15mg/g, and the subsequent elution of uranyl species with KCl solution. Furthermore, the porous and dynamic nature of the A 3 Ga 5 S 9 ·xH 2 O framework coupled with effective UO 2 2+ ···S 2– bonding interactions makes it a good potential sorbent for uranyl remediation from aqueous media.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2026

On-Chip Tuning of Superconductivity in Fullerides via Current-Driven Rb + Intercalation

An in-operando electro-intercalation method for the on-chip synthesis of alkali-metal-intercalated materials and their Raman spectroscopic and transport characterization in ultrahigh vacuum (UHV) is developed. We apply this method to synthesize fulleride superconductors via Rb + intercalation into a C 60 film. During the intercalation, we monitor the stoichiometry via UHV-Raman spectroscopy and probe superconductivity via transport measurements. An increase of the superconducting transition temperature from 7.0 K to 14.5 K is observed when the stoichiometry is tuned from Rb 2.7 C 60 to Rb 3 C 60 . In our experiment, an ionic Rb+ flux into the host material is induced by an applied electronic current via a Butler–Volmer-type mechanism. Electro-intercalation captivates through improved stoichiometric precision, the ability to smoothly vary stoichiometry via duration of current application, and the absence of a lower limit of the volume of the host material. It represents a powerful concept for the on-chip synthesis of intercalated materials, battery research, and beyond.

Raman↗
DOE OSTI2021

A series of Rb 4 Ln 2 (P 2 S 6 )(PS 4 ) 2 (Ln = La, Ce, Pr, Nd, Sm, Gd) rare earth thiophosphates with two distinct thiophosphate units [P V S 4 ] 3- and [P IV 2 S 6 ] 4-

A series of rubidium rare earth thiophosphates with the formula Rb 4 Ln 2 (P 2 S 6 )(PS 4 ) 2 (Ln = La, Ce, Pr, Nd, Sm, and Gd) were synthesized using the high temperature molten flux crystal growth method utilizing a RbBr flux. Single crystals of all title compounds, as well as phase pure powders of the La-, Ce-, and Sm-containing compositions, were obtained. Single crystals of the title compounds were characterized by single crystal and powder X-ray diffraction for structure and phase identification. Rb 4 Ln 2 (P 2 S 6 )(PS 4 ) 2 crystallizes in the monoclinic crystal system adopting the P2 1 /n space group for the large rare earths (Ln = La, Ce, Pr) and the C2/c space group for the smaller rare earths (Ln = Nd, Sm, Gd). This Rb 4 Ln 2 (P 2 S 6 )(PS 4 ) 2 series is a rare example of thiophosphates containing both tetrahedral [P V S 4 ] 3– and dimeric [P IV 2 S 6 ] 4– thiophosphate units that, in this structural family, link corrugated rare earth sulfide chains into sheets. Here, the band gaps of the materials were determined from UV–Vis data and the fluorescence spectrum of Rb 4 Ce 2 (P 2 S 6 )(PS 4 ) 2 was collected. Optical band gaps were estimated to be 2.9 and 2.4 for the Nd and Sm analogues, respectively.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

Polymorphism in A 3 MF 6 (A = Rb, Cs; M = Al, Ga) grown using mixed halide fluxes

Single crystals of A 3 MF 6 (A = Rb, Cs; M = Al, Ga) were grown from mixed alkali chloride/fluoride fluxes in sealed silver tubes. For Cs 3 AlF 6 and Cs 3 GaF 6 , two polymorphs were observed at room temperature: m-Cs 3 MF 6 and o-Cs 3 MF 6 . For the two Rb containing compositions, only one room temperature polymorph was observed: o-Rb 3 AlF 6 and t-Rb 3 GaF 6 , respectively. Simultaneous TGA/DSC and high temperature SCXRD/PXRD were used to study the high temperature behavior of A 3 MF 6 . Here, the compounds of all four compositions were found to undergo structure transitions upon heating to the same cubic structure type, c-A 3 MF 6 .

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2023

Cross sections of the 83 Rb⁢(p,γ)⁢ 84 Sr and 84 Kr⁢(p,γ)⁢ 85 Rb reactions at energies characteristic of the astrophysical γ process

We have measured the cross section of the Rb 83 ( p , γ ) Sr 84 radiative capture reaction in inverse kinematics using a radioactive beam of Rb 83 at incident energies of 2.4 and 2.7 A MeV. Prior to the radioactive beam measurement, the Kr 84 ( p , γ ) Rb 85 radiative capture reaction was measured in inverse kinematics using a stable beam of Kr 84 at an incident energy of 2.7 A MeV. The effective relative kinetic energies of these measurements lie within the relevant energy window for the γ process in supernovae. The central values of the measured partial cross sections of both reactions were found to be 0.17 – 0.42 times the predictions of statistical model calculations. Assuming the predicted cross section at other energies is reduced by the same factor leads to a slightly higher calculated abundance of the p nucleus Sr 84 , caused by the reduced rate of the Sr 84 ( γ , p ) Rb 83 reaction derived from the present measurement.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2020

Materials Data on Rb(WO3)3 by Materials Project

Rb(WO3)3 crystallizes in the monoclinic P2 space group. The structure is three-dimensional. there are two inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded to twelve O2- atoms to form RbO12 cuboctahedra that share edges with twelve WO6 octahedra and faces with two equivalent RbO12 cuboctahedra. There are a spread of Rb–O bond distances ranging from 3.34–3.38 Å. In the second Rb1+ site, Rb1+ is bonded to twelve O2- atoms to form RbO12 cuboctahedra that share edges with twelve WO6 octahedra and faces with two equivalent RbO12 cuboctahedra. There are a spread of Rb–O bond distances ranging from 3.35–3.38 Å. There are six inequivalent W+5.67+ sites. In the first W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form WO6 octahedra that share corners with six WO6 octahedra and edges with four RbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–31°. There is two shorter (1.94 Å) and four longer (1.95 Å) W–O bond length. In the second W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form WO6 octahedra that share corners with six WO6 octahedra and edges with four RbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–31°. There are a spread of W–O bond distances ranging from 1.93–1.95 Å. In the third W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form WO6 octahedra that share corners with six WO6 octahedra and edges with four RbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–31°. There are a spread of W–O bond distances ranging from 1.95–2.00 Å. In the fourth W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form WO6 octahedra that share corners with six WO6 octahedra and edges with four RbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–31°. There is two shorter (1.94 Å) and four longer (1.95 Å) W–O bond length. In the fifth W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form WO6 octahedra that share corners with six WO6 octahedra and edges with four RbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–31°. There is two shorter (1.92 Å) and four longer (1.96 Å) W–O bond length. In the sixth W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form WO6 octahedra that share corners with six WO6 octahedra and edges with four RbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–31°. There are a spread of W–O bond distances ranging from 1.90–1.97 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a linear geometry to two W+5.67+ atoms. In the second O2- site, O2- is bonded in a linear geometry to two W+5.67+ atoms. In the third O2- site, O2- is bonded in a linear geometry to two W+5.67+ atoms. In the fourth O2- site, O2- is bonded in a linear geometry to two W+5.67+ atoms. In the fifth O2- site, O2- is bonded in a linear geometry to two W+5.67+ atoms. In the sixth O2- site, O2- is bonded in a linear geometry to two W+5.67+ atoms. In the seventh O2- site, O2- is bonded in a bent 150 degrees geometry to two Rb1+ and two W+5.67+ atoms. In the eighth O2- site, O2- is bonded in a bent 150 degrees geometry to two Rb1+ and two W+5.67+ atoms. In the ninth O2- site, O2- is bonded in a bent 150 degrees geometry to two Rb1+ and two W+5.67+ atoms. In the tenth O2- site, O2- is bonded in a bent 150 degrees geometry to two Rb1+ and two W+5.67+ atoms. In the eleventh O2- site, O2- is bonded in a bent 150 degrees geometry to two Rb1+ and two W+5.67+ atoms. In the twelfth O2- site, O2- is bonded in a bent 150 degrees geometry to two Rb1+ and two W+5.67+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Rb(SnSe2)2 by Materials Project

Rb(SnSe2)2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Rb–Se bond distances ranging from 3.48–4.05 Å. In the second Rb1+ site, Rb1+ is bonded in a 7-coordinate geometry to seven Se2- atoms. There are a spread of Rb–Se bond distances ranging from 3.57–4.14 Å. There are four inequivalent Sn+3.50+ sites. In the first Sn+3.50+ site, Sn+3.50+ is bonded to four Se2- atoms to form a mixture of corner and edge-sharing SnSe4 tetrahedra. There are a spread of Sn–Se bond distances ranging from 2.50–2.61 Å. In the second Sn+3.50+ site, Sn+3.50+ is bonded to four Se2- atoms to form corner-sharing SnSe4 tetrahedra. There are a spread of Sn–Se bond distances ranging from 2.54–2.61 Å. In the third Sn+3.50+ site, Sn+3.50+ is bonded to four Se2- atoms to form a mixture of corner and edge-sharing SnSe4 tetrahedra. There are a spread of Sn–Se bond distances ranging from 2.48–2.63 Å. In the fourth Sn+3.50+ site, Sn+3.50+ is bonded in a distorted rectangular see-saw-like geometry to four Se2- atoms. There are a spread of Sn–Se bond distances ranging from 2.77–3.22 Å. There are eight inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a 3-coordinate geometry to one Rb1+ and two Sn+3.50+ atoms. In the second Se2- site, Se2- is bonded in a 4-coordinate geometry to three Rb1+ and two Sn+3.50+ atoms. In the third Se2- site, Se2- is bonded in a distorted rectangular see-saw-like geometry to two Rb1+ and two Sn+3.50+ atoms. In the fourth Se2- site, Se2- is bonded in a 5-coordinate geometry to three equivalent Rb1+ and two Sn+3.50+ atoms. In the fifth Se2- site, Se2- is bonded in a 3-coordinate geometry to one Rb1+ and two Sn+3.50+ atoms. In the sixth Se2- site, Se2- is bonded in a 5-coordinate geometry to three Rb1+ and two Sn+3.50+ atoms. In the seventh Se2- site, Se2- is bonded in a distorted water-like geometry to one Rb1+ and two Sn+3.50+ atoms. In the eighth Se2- site, Se2- is bonded in a 2-coordinate geometry to one Rb1+ and two Sn+3.50+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Rb(Zr3Te4)4 by Materials Project

Rb(Zr3Te4)4 crystallizes in the trigonal P3 space group. The structure is three-dimensional. there are two inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded in a 9-coordinate geometry to nine Te2- atoms. There are a spread of Rb–Te bond distances ranging from 3.67–4.12 Å. In the second Rb1+ site, Rb1+ is bonded in a 9-coordinate geometry to nine Te2- atoms. There are a spread of Rb–Te bond distances ranging from 3.67–4.11 Å. There are eight inequivalent Zr+2.58+ sites. In the first Zr+2.58+ site, Zr+2.58+ is bonded to six Te2- atoms to form a mixture of edge, face, and corner-sharing ZrTe6 octahedra. The corner-sharing octahedra tilt angles range from 42–53°. There are a spread of Zr–Te bond distances ranging from 2.90–3.06 Å. In the second Zr+2.58+ site, Zr+2.58+ is bonded to six Te2- atoms to form a mixture of edge, face, and corner-sharing ZrTe6 octahedra. The corner-sharing octahedra tilt angles range from 43–52°. There are a spread of Zr–Te bond distances ranging from 2.90–3.04 Å. In the third Zr+2.58+ site, Zr+2.58+ is bonded to six Te2- atoms to form a mixture of edge, face, and corner-sharing ZrTe6 octahedra. The corner-sharing octahedra tilt angles range from 42–53°. There are a spread of Zr–Te bond distances ranging from 2.91–3.06 Å. In the fourth Zr+2.58+ site, Zr+2.58+ is bonded to six Te2- atoms to form a mixture of edge, face, and corner-sharing ZrTe6 octahedra. The corner-sharing octahedra tilt angles range from 42–54°. There are a spread of Zr–Te bond distances ranging from 2.90–3.10 Å. In the fifth Zr+2.58+ site, Zr+2.58+ is bonded to six Te2- atoms to form a mixture of edge, face, and corner-sharing ZrTe6 octahedra. The corner-sharing octahedra tilt angles range from 43–53°. There are a spread of Zr–Te bond distances ranging from 2.91–3.01 Å. In the sixth Zr+2.58+ site, Zr+2.58+ is bonded to six Te2- atoms to form a mixture of edge, face, and corner-sharing ZrTe6 octahedra. The corner-sharing octahedra tilt angles range from 43–53°. There are a spread of Zr–Te bond distances ranging from 2.91–3.01 Å. In the seventh Zr+2.58+ site, Zr+2.58+ is bonded to six Te2- atoms to form a mixture of edge, face, and corner-sharing ZrTe6 octahedra. The corner-sharing octahedra tilt angles range from 43–54°. There are a spread of Zr–Te bond distances ranging from 2.91–3.00 Å. In the eighth Zr+2.58+ site, Zr+2.58+ is bonded to six Te2- atoms to form a mixture of edge, face, and corner-sharing ZrTe6 octahedra. The corner-sharing octahedra tilt angles range from 43–54°. There are a spread of Zr–Te bond distances ranging from 2.91–3.00 Å. There are twelve inequivalent Te2- sites. In the first Te2- site, Te2- is bonded in a 5-coordinate geometry to one Rb1+ and four Zr+2.58+ atoms. In the second Te2- site, Te2- is bonded in a 4-coordinate geometry to four Zr+2.58+ atoms. In the third Te2- site, Te2- is bonded in a 5-coordinate geometry to one Rb1+ and four Zr+2.58+ atoms. In the fourth Te2- site, Te2- is bonded in a 6-coordinate geometry to two Rb1+ and four Zr+2.58+ atoms. In the fifth Te2- site, Te2- is bonded to six Zr+2.58+ atoms to form distorted face-sharing TeZr6 pentagonal pyramids. In the sixth Te2- site, Te2- is bonded to six Zr+2.58+ atoms to form distorted face-sharing TeZr6 pentagonal pyramids. In the seventh Te2- site, Te2- is bonded in a 4-coordinate geometry to four Zr+2.58+ atoms. In the eighth Te2- site, Te2- is bonded in a 5-coordinate geometry to one Rb1+ and four Zr+2.58+ atoms. In the ninth Te2- site, Te2- is bonded in a 5-coordinate geometry to one Rb1+ and four Zr+2.58+ atoms. In the tenth Te2- site, Te2- is bonded to six Zr+2.58+ atoms to form distorted face-sharing TeZr6 pentagonal pyramids. In the eleventh Te2- site, Te2- is bonded to six Zr+2.58+ atoms to form distorted face-sharing TeZr6 pentagonal pyramids. In the twelfth Te2- site, Te2- is bonded to six Zr+2.58+ atoms to form distorted face-sharing TeZr6 pentagonal pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Rb(YbS2)3 by Materials Project

YbRb(YbS2)2(S)2 crystallizes in the orthorhombic Cmmm space group. The structure is two-dimensional and consists of four hydrogen sulfide molecules; two ytterbium molecules; and one Rb(YbS2)2 sheet oriented in the (0, 0, 1) direction. In the Rb(YbS2)2 sheet, Rb1+ is bonded in a square co-planar geometry to four equivalent S+1.33- atoms. All Rb–S bond lengths are 3.29 Å. Yb+2.33+ is bonded in a linear geometry to two equivalent S+1.33- atoms. Both Yb–S bond lengths are 2.62 Å. S+1.33- is bonded in a 3-coordinate geometry to one Rb1+, one Yb+2.33+, and one S+1.33- atom. The S–S bond length is 2.10 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Rb(WO3)4 by Materials Project

Rb(WO3)4 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are two inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded to twelve O2- atoms to form RbO12 cuboctahedra that share edges with twelve WO6 octahedra and faces with two equivalent RbO12 cuboctahedra. There are eight shorter (3.35 Å) and four longer (3.36 Å) Rb–O bond lengths. In the second Rb1+ site, Rb1+ is bonded to twelve O2- atoms to form RbO12 cuboctahedra that share edges with twelve WO6 octahedra and a faceface with one RbO12 cuboctahedra. There are a spread of Rb–O bond distances ranging from 3.28–3.45 Å. There are four inequivalent W+5.75+ sites. In the first W+5.75+ site, W+5.75+ is bonded to six O2- atoms to form WO6 octahedra that share corners with six WO6 octahedra and edges with four RbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–31°. There are a spread of W–O bond distances ranging from 1.93–1.96 Å. In the second W+5.75+ site, W+5.75+ is bonded to six O2- atoms to form WO6 octahedra that share corners with six WO6 octahedra and edges with two equivalent RbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–29°. There are a spread of W–O bond distances ranging from 1.93–1.95 Å. In the third W+5.75+ site, W+5.75+ is bonded to six O2- atoms to form WO6 octahedra that share corners with six WO6 octahedra and edges with three RbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–31°. There are a spread of W–O bond distances ranging from 1.93–1.95 Å. In the fourth W+5.75+ site, W+5.75+ is bonded to six O2- atoms to form WO6 octahedra that share corners with six WO6 octahedra and edges with three RbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–31°. There are a spread of W–O bond distances ranging from 1.93–1.97 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 150 degrees geometry to two Rb1+ and two W+5.75+ atoms. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to one Rb1+ and two W+5.75+ atoms. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to two Rb1+ and two W+5.75+ atoms. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to one Rb1+ and two W+5.75+ atoms. In the fifth O2- site, O2- is bonded in a linear geometry to two W+5.75+ atoms. In the sixth O2- site, O2- is bonded in a linear geometry to two W+5.75+ atoms. In the seventh O2- site, O2- is bonded in a linear geometry to two equivalent W+5.75+ atoms. In the eighth O2- site, O2- is bonded in a linear geometry to two equivalent W+5.75+ atoms. In the ninth O2- site, O2- is bonded in a linear geometry to two equivalent W+5.75+ atoms. In the tenth O2- site, O2- is bonded in a linear geometry to two equivalent W+5.75+ atoms. In the eleventh O2- site, O2- is bonded in a bent 150 degrees geometry to one Rb1+ and two W+5.75+ atoms. In the twelfth O2- site, O2- is bonded in a bent 150 degrees geometry to two Rb1+ and two W+5.75+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Rb(WO3)3 by Materials Project

Rb(WO3)3 crystallizes in the monoclinic P2 space group. The structure is three-dimensional. there are two inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded to twelve O2- atoms to form RbO12 cuboctahedra that share edges with twelve WO6 octahedra and faces with two equivalent RbO12 cuboctahedra. There are a spread of Rb–O bond distances ranging from 3.34–3.38 Å. In the second Rb1+ site, Rb1+ is bonded to twelve O2- atoms to form RbO12 cuboctahedra that share edges with twelve WO6 octahedra and faces with two equivalent RbO12 cuboctahedra. There are a spread of Rb–O bond distances ranging from 3.36–3.38 Å. There are six inequivalent W+5.67+ sites. In the first W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form WO6 octahedra that share corners with six WO6 octahedra and edges with four RbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–31°. There is two shorter (1.95 Å) and four longer (2.00 Å) W–O bond length. In the second W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form WO6 octahedra that share corners with six WO6 octahedra and edges with four RbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–31°. There is two shorter (1.92 Å) and four longer (1.95 Å) W–O bond length. In the third W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form WO6 octahedra that share corners with six WO6 octahedra and edges with four RbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–32°. There is two shorter (1.94 Å) and four longer (2.00 Å) W–O bond length. In the fourth W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form WO6 octahedra that share corners with six WO6 octahedra and edges with four RbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–31°. There is two shorter (1.90 Å) and four longer (1.96 Å) W–O bond length. In the fifth W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form WO6 octahedra that share corners with six WO6 octahedra and edges with four RbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–32°. There is two shorter (1.92 Å) and four longer (1.95 Å) W–O bond length. In the sixth W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form WO6 octahedra that share corners with six WO6 octahedra and edges with four RbO12 cuboctahedra. The corner-sharing octahedra tilt angles range from 0–31°. There are a spread of W–O bond distances ranging from 1.90–1.96 Å. There are twelve inequivalent O2- sites. In the first O2- site, O2- is bonded in a linear geometry to two W+5.67+ atoms. In the second O2- site, O2- is bonded in a linear geometry to two W+5.67+ atoms. In the third O2- site, O2- is bonded in a linear geometry to two W+5.67+ atoms. In the fourth O2- site, O2- is bonded in a linear geometry to two W+5.67+ atoms. In the fifth O2- site, O2- is bonded in a linear geometry to two W+5.67+ atoms. In the sixth O2- site, O2- is bonded in a linear geometry to two W+5.67+ atoms. In the seventh O2- site, O2- is bonded in a bent 150 degrees geometry to two Rb1+ and two W+5.67+ atoms. In the eighth O2- site, O2- is bonded in a bent 150 degrees geometry to two Rb1+ and two W+5.67+ atoms. In the ninth O2- site, O2- is bonded in a bent 150 degrees geometry to two Rb1+ and two W+5.67+ atoms. In the tenth O2- site, O2- is bonded in a bent 150 degrees geometry to two Rb1+ and two W+5.67+ atoms. In the eleventh O2- site, O2- is bonded in a bent 150 degrees geometry to two Rb1+ and two W+5.67+ atoms. In the twelfth O2- site, O2- is bonded in a bent 150 degrees geometry to two Rb1+ and two W+5.67+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Machine learning analysis of RB-TnSeq fitness data predicts functional gene modules in Pseudomonas putida KT2440

ABSTRACT There is growing interest in engineering Pseudomonas putida KT2440 as a microbial chassis for the conversion of renewable and waste-based feedstocks, and metabolic engineering of P. putida relies on the understanding of the functional relationships between genes. In this work, independent component analysis (ICA) was applied to a compendium of existing fitness data from randomly barcoded transposon insertion sequencing (RB-TnSeq) of P. putida KT2440 grown in 179 unique experimental conditions. ICA identified 84 independent groups of genes, which we call fModules (“functional modules”), where gene members displayed shared functional influence in a specific cellular process. This machine learning-based approach both successfully recapitulated previously characterized functional relationships and established hitherto unknown associations between genes. Selected gene members from fModules for hydroxycinnamate metabolism and stress resistance, acetyl coenzyme A assimilation, and nitrogen metabolism were validated with engineered mutants of P. putida . Additionally, functional gene clusters from ICA of RB-TnSeq data sets were compared with regulatory gene clusters from prior ICA of RNAseq data sets to draw connections between gene regulation and function. Because ICA profiles the functional role of several distinct gene networks simultaneously, it can reduce the time required to annotate gene function relative to manual curation of RB-TnSeq data sets. IMPORTANCE This study demonstrates a rapid, automated approach for elucidating functional modules within complex genetic networks. While Pseudomonas putida randomly barcoded transposon insertion sequencing data were used as a proof of concept, this approach is applicable to any organism with existing functional genomics data sets and may serve as a useful tool for many valuable applications, such as guiding metabolic engineering efforts in other microbes or understanding functional relationships between virulence-associated genes in pathogenic microbes. Furthermore, this work demonstrates that comparison of data obtained from independent component analysis of transcriptomics and gene fitness datasets can elucidate regulatory-functional relationships between genes, which may have utility in a variety of applications, such as metabolic modeling, strain engineering, or identification of antimicrobial drug targets.

09 BIOMASS FUELS↗
DOE OSTI2022

ACuZrQ 3 (A = Rb, Cs; Q = S, Se, Te): Direct Bandgap Semiconductors and Metals with Ultralow Thermal Conductivity

ACuZrQ 3 (A = Rb, Cs; Q = S, Se, Te) were synthesized as black platelet crystals. RbCuZrS 3 , RbCuZrSe 3 , and CsCuZrS 3 crystallize in the KCuZrSe 3 structure type with space group Cmcm, and RbCuZrTe 3 and CsCuZrTe 3 crystallize in the lower symmetry space group Pnma. The tellurides exhibit a second order Jahn-Teller distortion with off-centering of Zr in its octahedral environment. The magnitude of the distortion is larger in RbCuZrTe 3 than in CsCuZrTe 3 . The structures of beta-CsCuS 4 and Rb 2 Cu 5 Te 5 were also determined. CsCuZrS 3 melts at 910 C-circle and exhibits partial decomposition upon heating at 275 C-circle, while CsCuZrTe 3 melts incongruently. Our DFT calculations of RbCuZrQ 3 (Q = S, Se) and CsCuZrS 3 indicate direct gap semiconductors in agreement with experiments. ACuZrTe 3 (A = Rb, Cs) were calculated to be metals which was confirmed for RbCuZrTe 3 with variable temperature conductivity measurements and consistent with heat capacity measurements. Spectroscopic measurements found a bandgap and work function of 1.44(5) eV and 4.89(5) eV for RbCuZrS 3 and 0.95(5) eV and 4.67(5) eV for RbCuZrSe 3 , respectively. Finally, RbCuZrTe 3 did not exhibit an optical bandgap and has a work function of 4.64(5) eV. RbCuZrTe 3 exhibits a low thermal conductivity under 0.5 W m -1 K -1 at room temperature.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2024

Colloidal AInSe 2 (A = K, Rb, Cs) Nanocrystals with Tunable Crystal and Band Structures

Wide band gap AInSe 2 (A = K, Rb, Cs) is an important interlayer material for improving the efficiency of Cu(In,Ga)(S,Se) 2 (CIGS) solar cells. Compared to high-vacuum deposition and solid-state synthesis, a less energyintensive method is of interest for its fabrication. Herein, we present the rapid, low-temperature colloidal synthesis of AInSe 2 nanocrystals that opens a pathway for convenient solution processing. The crystal structures and electronic band structures of the nanocrystals were studied, and their particle morphology was found to be dependent on the choice of alkali metal and selenium precursors. Homogeneous solid solution (K,Rb,Cs)InSe 2 nanocrystals were synthesized using a mixture of alkali metal precursors. Their compositions, lattice parameters, and band gaps were easily tuned based on the K:Rb:Cs precursor ratio, providing potential for interface engineering of CIGS nanocrystal-based solar cells.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2025

Hyperfine-to-rotational energy transfer in ultracold atom–molecule collisions of Rb and KRb

Energy transfer between different mechanical degrees of freedom in atom–molecule collisions has been studied and largely understood. However, systems involving spins remain less explored. Here, in this study, we directly observed energy transfer from atomic hyperfine to molecular rotation in the 87 Rb ($| {F}_{a},{M}_{{F}_{a}}\rangle =| 2,2\rangle$) + 40 K 87 Rb (X 1 Σ + , rotational state N = 0) ⟶ Rb ($| 1,1\rangle$) + KRb ( N = 0, 1, 2) collision with state-to-state precision. We also performed quantum scattering calculations that rigorously included the coupling between spin and rotational degrees of freedom at short range under the assumption of rigid-rotor KRb monomers moving along a single potential energy surface. The calculated product rotational state distribution deviates from the observations even after extensive tuning of the atom–molecule potential energy surface. In addition, our ab initio calculations indicate that spin–rotation coupling is enhanced close to a conical intersection that is energetically accessible at short range. This, together with the deviation, suggests that vibrational degrees of freedom and conical intersections play an important part in the coupling. Our observations confirm that spin is coupled to mechanical rotation at short range and establish a benchmark for future theoretical studies.

chemical physics↗
DOE OSTI2022

Determination of β -decay feeding patterns of 88 Rb and 88 Kr using the Modular Total Absorption Spectrometer at ORNL HRIBF

We report precise determination of ground-state feeding in the β decay of fission products is an important but challenging component in modeling reactor antineutrino flux and reactor decay heat. The Modular Total Absorption Spectrometer (MTAS) is a versatile NaI(Tl) detector array that determines the true β-decay pattern free from the pandemonium effect, including precise ground-state feeding intensities. In this paper, we report MTAS results of the β feeding intensities of 88 Rb and 88 Kr, fission products with large cumulative yields in nuclear reactors. By comparing MTAS results with previous measurements, 88 Rb provides a validation of MTAS's ability to determine ground-state feedings in β decays, while the precision of 88 Kr ground-state feeding is improved when compared with the Evaluated Nuclear Structure Data File (ENSDF). The investigation of sources that contribute to β feeding branching uncertainties in MTAS experiments is discussed in detail. Lastly, the deconvolution of 88 Rb decay spectra suggests that MTAS can distinguish an allowed β spectral shape from a first forbidden unique β spectral shape.

73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
DOE OSTI2023

CDK4/6 inhibition enhances SHP2 inhibitor efficacy and is dependent upon RB function in malignant peripheral nerve sheath tumors

Malignant peripheral nerve sheath tumors (MPNSTs) are highly aggressive soft tissue sarcomas with limited treatment options, and new effective therapeutic strategies are desperately needed. We observe antiproliferative potency of genetic depletion of PTPN11 or pharmacological inhibition using the SHP2 inhibitor (SHP2i) TNO155. Our studies into the signaling response to SHP2i reveal that resistance to TNO155 is partially mediated by reduced RB function, and we therefore test the addition of a CDK4/6 inhibitor (CDK4/6i) to enhance RB activity and improve TNO155 efficacy. In combination, TNO155 attenuates the adaptive response to CDK4/6i, potentiates its antiproliferative effects, and converges on enhancement of RB activity, with greater suppression of cell cycle and inhibitor-of-apoptosis proteins, leading to deeper and more durable antitumor activity in in vitro and in vivo patient-derived models of MPNST, relative to either single agent. Overall, our study provides timely evidence to support the clinical advancement of this combination strategy in patients with MPNST and other tumors driven by loss of NF1.

60 APPLIED LIFE SCIENCES↗