Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “Rb”

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.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 793 records · Page 44
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on RbP(HO2)2 by Materials Project

RbH2PO4 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. there are four inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Rb–O bond distances ranging from 3.05–3.10 Å. In the second Rb1+ site, Rb1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Rb–O bond distances ranging from 3.03–3.12 Å. In the third Rb1+ site, Rb1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Rb–O bond distances ranging from 3.01–3.17 Å. In the fourth Rb1+ site, Rb1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Rb–O bond distances ranging from 3.02–3.15 Å. There are four inequivalent P5+ sites. In the first P5+ site, P5+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of P–O bond distances ranging from 1.52–1.60 Å. In the second P5+ site, P5+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of P–O bond distances ranging from 1.52–1.60 Å. In the third P5+ site, P5+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of P–O bond distances ranging from 1.52–1.60 Å. In the fourth P5+ site, P5+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of P–O bond distances ranging from 1.52–1.60 Å. There are eight inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.03 Å) and one longer (1.51 Å) H–O bond length. In the second H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.03 Å) and one longer (1.52 Å) H–O bond length. In the third H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.03 Å) and one longer (1.50 Å) H–O bond length. In the fourth H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.03 Å) and one longer (1.53 Å) H–O bond length. In the fifth H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.04 Å) and one longer (1.51 Å) H–O bond length. In the sixth H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.04 Å) and one longer (1.51 Å) H–O bond length. In the seventh H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.05 Å) and one longer (1.49 Å) H–O bond length. In the eighth H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.05 Å) and one longer (1.47 Å) H–O bond length. There are sixteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Rb1+, one P5+, and one H1+ atom. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Rb1+, one P5+, and one H1+ atom. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Rb1+, one P5+, and one H1+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two Rb1+, one P5+, and one H1+ atom. In the fifth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Rb1+, one P5+, and one H1+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Rb1+, one P5+, and one H1+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Rb1+, one P5+, and one H1+ atom. In the eighth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two Rb1+, one P5+, and one H1+ atom. In the ninth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Rb1+, one P5+, and one H1+ atom. In the tenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Rb1+, one P5+, and one H1+ atom. In the eleventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Rb1+, one P5+, and one H1+ atom. In the twelfth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two Rb1+, one P5+, and one H1+ atom. In the thirteenth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Rb1+, one P5+, and one H1+ atom. In the fourteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Rb1+, one P5+, and one H1+ atom. In the fifteenth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Rb1+, one P5+, and one H1+ atom. In the sixteenth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two Rb1+, one P5+, and one H1+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Rb7(FeTe2)4 by Materials Project

Rb7(FeTe2)4 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are four inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded in a 8-coordinate geometry to eight Te2- atoms. There are a spread of Rb–Te bond distances ranging from 3.69–3.98 Å. In the second Rb1+ site, Rb1+ is bonded in a 8-coordinate geometry to eight Te2- atoms. There are a spread of Rb–Te bond distances ranging from 3.69–4.33 Å. In the third Rb1+ site, Rb1+ is bonded in a 7-coordinate geometry to seven Te2- atoms. There are a spread of Rb–Te bond distances ranging from 3.65–4.16 Å. In the fourth Rb1+ site, Rb1+ is bonded in a 5-coordinate geometry to five Te2- atoms. There are a spread of Rb–Te bond distances ranging from 3.70–4.17 Å. There are two inequivalent Fe+2.25+ sites. In the first Fe+2.25+ site, Fe+2.25+ is bonded to four Te2- atoms to form edge-sharing FeTe4 tetrahedra. There are a spread of Fe–Te bond distances ranging from 2.59–2.63 Å. In the second Fe+2.25+ site, Fe+2.25+ is bonded to four Te2- atoms to form edge-sharing FeTe4 tetrahedra. There are a spread of Fe–Te bond distances ranging from 2.59–2.63 Å. There are four inequivalent Te2- sites. In the first Te2- site, Te2- is bonded in a 8-coordinate geometry to five Rb1+ and three Fe+2.25+ atoms. In the second Te2- site, Te2- is bonded in a 8-coordinate geometry to five Rb1+ and three Fe+2.25+ atoms. In the third Te2- site, Te2- is bonded in a 8-coordinate geometry to seven Rb1+ and one Fe+2.25+ atom. In the fourth Te2- site, Te2- is bonded in a distorted body-centered cubic geometry to seven Rb1+ and one Fe+2.25+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Rb4Sn(Te2O)2 by Materials Project

Rb4Sn(Te2O)2 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are two inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded in a distorted water-like geometry to three equivalent Te+0.50- and two equivalent O2- atoms. There are a spread of Rb–Te bond distances ranging from 3.87–4.29 Å. There are one shorter (2.80 Å) and one longer (2.85 Å) Rb–O bond lengths. In the second Rb1+ site, Rb1+ is bonded in a distorted single-bond geometry to three equivalent Te+0.50- and one O2- atom. There are a spread of Rb–Te bond distances ranging from 3.63–4.06 Å. The Rb–O bond length is 2.85 Å. Sn2+ is bonded to four Te+0.50- atoms to form SnTe4 tetrahedra that share corners with two equivalent ORb3Te tetrahedra. There are two shorter (2.76 Å) and two longer (2.88 Å) Sn–Te bond lengths. There are two inequivalent Te+0.50- sites. In the first Te+0.50- site, Te+0.50- is bonded in a single-bond geometry to one Sn2+ and one O2- atom. The Te–O bond length is 1.94 Å. In the second Te+0.50- site, Te+0.50- is bonded in a 7-coordinate geometry to six Rb1+ and one Sn2+ atom. O2- is bonded to three Rb1+ and one Te+0.50- atom to form distorted ORb3Te tetrahedra that share a cornercorner with one SnTe4 tetrahedra and corners with two equivalent ORb3Te tetrahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on RbEu3 by Materials Project

RbEu3 is beta Cu3Ti-like structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Rb is bonded to twelve Eu atoms to form RbEu12 cuboctahedra that share corners with four equivalent RbEu12 cuboctahedra, corners with eight equivalent EuRb4Eu8 cuboctahedra, edges with eight equivalent RbEu12 cuboctahedra, edges with sixteen equivalent EuRb4Eu8 cuboctahedra, faces with four equivalent RbEu12 cuboctahedra, and faces with fourteen EuRb4Eu8 cuboctahedra. There are four shorter (4.22 Å) and eight longer (4.25 Å) Rb–Eu bond lengths. There are two inequivalent Eu sites. In the first Eu site, Eu is bonded to four equivalent Rb and eight Eu atoms to form EuRb4Eu8 cuboctahedra that share corners with twelve equivalent EuRb4Eu8 cuboctahedra, edges with eight equivalent RbEu12 cuboctahedra, edges with sixteen EuRb4Eu8 cuboctahedra, faces with four equivalent RbEu12 cuboctahedra, and faces with fourteen EuRb4Eu8 cuboctahedra. There are four shorter (4.22 Å) and four longer (4.25 Å) Eu–Eu bond lengths. In the second Eu site, Eu is bonded to four equivalent Rb and eight equivalent Eu atoms to form distorted EuRb4Eu8 cuboctahedra that share corners with four equivalent EuRb4Eu8 cuboctahedra, corners with eight equivalent RbEu12 cuboctahedra, edges with twenty-four EuRb4Eu8 cuboctahedra, faces with six equivalent RbEu12 cuboctahedra, and faces with twelve EuRb4Eu8 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on RbMg30BO31 by Materials Project

RbMg30BO31 crystallizes in the orthorhombic Pmm2 space group. The structure is three-dimensional. Rb is bonded in a 3-coordinate geometry to three O atoms. There are two shorter (2.45 Å) and one longer (2.50 Å) Rb–O bond lengths. There are sixteen inequivalent Mg sites. In the first Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four MgO6 octahedra, edges with ten MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. The corner-sharing octahedral tilt angles are 0°. There are a spread of Mg–O bond distances ranging from 1.98–2.21 Å. In the second Mg site, Mg is bonded to six O atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are a spread of Mg–O bond distances ranging from 2.00–2.22 Å. In the third Mg site, Mg is bonded to five O atoms to form MgO5 square pyramids that share corners with four MgO6 octahedra, corners with four MgO5 square pyramids, and edges with eight MgO6 octahedra. The corner-sharing octahedra tilt angles range from 2–4°. There are a spread of Mg–O bond distances ranging from 2.04–2.28 Å. In the fourth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with two equivalent MgO6 octahedra, corners with two equivalent MgO5 square pyramids, edges with ten MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. The corner-sharing octahedral tilt angles are 2°. There are a spread of Mg–O bond distances ranging from 1.97–2.22 Å. In the fifth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four MgO6 octahedra, corners with two equivalent MgO5 square pyramids, edges with ten MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. The corner-sharing octahedral tilt angles are 0°. There are a spread of Mg–O bond distances ranging from 2.09–2.14 Å. In the sixth Mg site, Mg is bonded to six O atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. There are a spread of Mg–O bond distances ranging from 2.09–2.21 Å. In the seventh Mg site, Mg is bonded to six O atoms to form distorted MgO6 octahedra that share corners with six MgO6 octahedra, edges with eight MgO6 octahedra, and edges with two MgO5 square pyramids. The corner-sharing octahedra tilt angles range from 3–33°. There are a spread of Mg–O bond distances ranging from 2.04–2.44 Å. In the eighth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, edges with nine MgO6 octahedra, and edges with three MgO5 square pyramids. The corner-sharing octahedra tilt angles range from 1–5°. There are a spread of Mg–O bond distances ranging from 2.10–2.21 Å. In the ninth Mg site, Mg is bonded to five O atoms to form distorted MgO5 square pyramids that share corners with four MgO6 octahedra, corners with four MgO5 square pyramids, and edges with seven MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–35°. There are a spread of Mg–O bond distances ranging from 1.96–2.42 Å. In the tenth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four MgO6 octahedra, corners with two equivalent MgO5 square pyramids, edges with ten MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. The corner-sharing octahedra tilt angles range from 0–2°. There are a spread of Mg–O bond distances ranging from 2.08–2.23 Å. In the eleventh Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four MgO6 octahedra, corners with two equivalent MgO5 square pyramids, edges with nine MgO6 octahedra, and an edgeedge with one MgO5 square pyramid. The corner-sharing octahedra tilt angles range from 3–9°. There are a spread of Mg–O bond distances ranging from 2.03–2.26 Å. In the twelfth Mg site, Mg is bonded to six O atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. There are a spread of Mg–O bond distances ranging from 2.09–2.23 Å. In the thirteenth Mg site, Mg is bonded to five O atoms to form MgO5 square pyramids that share corners with four MgO6 octahedra, corners with four MgO5 square pyramids, and edges with eight MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–8°. There are a spread of Mg–O bond distances ranging from 2.09–2.19 Å. In the fourteenth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four MgO6 octahedra, corners with two equivalent MgO5 square pyramids, edges with nine MgO6 octahedra, and edges with two equivalent MgO5 square pyramids. The corner-sharing octahedra tilt angles range from 2–15°. There are a spread of Mg–O bond distances ranging from 2.09–2.27 Å. In the fifteenth Mg site, Mg is bonded to six O atoms to form MgO6 octahedra that share corners with four MgO6 octahedra, corners with two equivalent MgO5 square pyramids, edges with ten MgO6 octahedra, and an edgeedge with one MgO5 square pyramid. The corner-sharing octahedra tilt angles range from 2–9°. There are a spread of Mg–O bond distances ranging from 2.10–2.25 Å. In the sixteenth Mg site, Mg is bonded to six O atoms to form a mixture of edge and corner-sharing MgO6 octahedra. The corner-sharing octahedra tilt angles range from 2–9°. There are a spread of Mg–O bond distances ranging from 2.09–2.33 Å. B is bonded in a distorted trigonal planar geometry to three O atoms. There is two shorter (1.43 Å) and one longer (1.46 Å) B–O bond length. There are seventeen inequivalent O sites. In the first O site, O is bonded to five Mg atoms to form OMg5 square pyramids that share corners with three OMg6 octahedra, corners with two equivalent OMg5 square pyramids, and edges with eight OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–10°. In the second O site, O is bonded to six Mg atoms to form a mixture of edge and corner-sharing OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. In the third O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with four OMg6 octahedra, corners with two equivalent OMg5 square pyramids, edges with ten OMg6 octahedra, and edges with two equivalent OMg5 square pyramids. The corner-sharing octahedra tilt angles range from 0–2°. In the fourth O site, O is bonded to one Rb and five Mg atoms to form ORbMg5 octahedra that share corners with four OMg5B octahedra and edges with ten OMg6 octahedra. The corner-sharing octahedra tilt angles range from 1–5°. In the fifth O site, O is bonded to five Mg and one B atom to form distorted OMg5B octahedra that share corners with four ORbMg5 octahedra, corners with three OMg5 square pyramids, and edges with eight OMg6 octahedra. The corner-sharing octahedral tilt angles are 1°. In the sixth O site, O is bonded to six Mg atoms to form a mixture of edge and corner-sharing OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–5°. In the seventh O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six OMg6 octahedra, edges with ten OMg6 octahedra, and edges with two equivalent OMg5 square pyramids. The corner-sharing octahedra tilt angles range from 0–1°. In the eighth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six OMg6 octahedra, edges with eight OMg6 octahedra, and edges with two OMg5 square pyramids. The corner-sharing octahedra tilt angles range from 1–10°. In the ninth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with six OMg6 octahedra, edges with ten ORbMg5 octahedra, and an edgeedge with one OMg5 square pyramid. The corner-sharing octahedra tilt angles range from 1–8°. In the tenth O site, O is bonded in a distorted single-bond geometry to four Mg and one B atom. In the eleventh O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with four OMg6 octahedra, edges with ten OMg6 octahedra, and edges with two equivalent OMg5 square pyramids. The corner-sharing octahedral tilt angles are 1°. In the twelfth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with four OMg6 octahedra, edges with ten ORbMg5 octahedra, and an edgeedge with one OMg5 square pyramid. The corner-sharing octahedra tilt angles range from 0–7°. In the thirteenth O site, O is bonded to six Mg atoms to form a mixture of edge and corner-sharing OMg6 octahedra. The corner-sharing octahedra tilt angles range from 1–2°. In the fourteenth O site, O is bonded to one Rb and five Mg atoms to form ORbMg5 octahedra that share corners with four OMg6 octahedra, corners with two equivalent OMg5 square pyramids, and edges with nine OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–8°. In the fifteenth O site, O is bonded to five Mg atoms to form OMg5 square pyramids that share corners with five OMg5B octahedra, corners with two OMg5 square pyramids, and edges with eight OMg6 octahedra. The corner-sharing octahedra tilt angles range from 1–90°. In the sixteenth O site, O is bonded to six Mg atoms to form a mixture of edge and corner-sharing OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–6°. In the seventeenth O site, O is bonded to six Mg atoms to form OMg6 octahedra that share corners with four OMg6 octahedra, corners with two equivalent OMg5 square pyramids, edges with eleven OMg6 octahedra, and an edgeedge with one OMg5 square pyramid. The corner-sharing octahedra tilt angles range from 0–4°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Rb7SmFe6(P4O17)2 by Materials Project

Rb7SmFe6(P4O17)2 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are four inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded in a 8-coordinate geometry to eleven O2- atoms. There are a spread of Rb–O bond distances ranging from 2.84–3.50 Å. In the second Rb1+ site, Rb1+ is bonded in a 1-coordinate geometry to ten O2- atoms. There are a spread of Rb–O bond distances ranging from 2.88–3.58 Å. In the third Rb1+ site, Rb1+ is bonded in a 1-coordinate geometry to four O2- atoms. There are a spread of Rb–O bond distances ranging from 2.82–3.31 Å. In the fourth Rb1+ site, Rb1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Rb–O bond distances ranging from 2.88–3.17 Å. Sm3+ is bonded to six O2- atoms to form SmO6 octahedra that share corners with six PO4 tetrahedra. There are two shorter (2.31 Å) and four longer (2.36 Å) Sm–O bond lengths. There are three inequivalent Fe3+ sites. In the first Fe3+ site, Fe3+ is bonded to six O2- atoms to form FeO6 octahedra that share corners with four PO4 tetrahedra, corners with two equivalent FeO5 trigonal bipyramids, and an edgeedge with one FeO6 octahedra. There are a spread of Fe–O bond distances ranging from 2.01–2.16 Å. In the second Fe3+ site, Fe3+ is bonded to five O2- atoms to form FeO5 trigonal bipyramids that share corners with two equivalent FeO6 octahedra and corners with four PO4 tetrahedra. The corner-sharing octahedra tilt angles range from 52–54°. There are a spread of Fe–O bond distances ranging from 1.96–2.06 Å. In the third Fe3+ site, Fe3+ is bonded to five O2- atoms to form FeO5 trigonal bipyramids that share corners with five PO4 tetrahedra. There are a spread of Fe–O bond distances ranging from 1.91–2.02 Å. There are four inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one SmO6 octahedra and corners with three FeO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 14°. There are a spread of P–O bond distances ranging from 1.54–1.57 Å. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one SmO6 octahedra, a cornercorner with one FeO6 octahedra, and corners with two FeO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 50–52°. There are a spread of P–O bond distances ranging from 1.54–1.57 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two equivalent FeO6 octahedra and corners with two FeO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 58–64°. There are a spread of P–O bond distances ranging from 1.55–1.57 Å. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one SmO6 octahedra, a cornercorner with one FeO6 octahedra, and corners with two FeO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 43–44°. There are a spread of P–O bond distances ranging from 1.55–1.57 Å. There are seventeen inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to two Rb1+, one Fe3+, and one P5+ atom. In the second O2- site, O2- is bonded in a 2-coordinate geometry to two Rb1+, one Fe3+, and one P5+ atom. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Rb1+, one Fe3+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to three Rb1+, one Fe3+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one Rb1+, one Fe3+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to one Rb1+ and three Fe3+ atoms. In the seventh O2- site, O2- is bonded in a bent 150 degrees geometry to one Fe3+ and one P5+ atom. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to two Rb1+, one Fe3+, and one P5+ atom. In the ninth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to two Rb1+, one Fe3+, and one P5+ atom. In the tenth O2- site, O2- is bonded in a 1-coordinate geometry to two Rb1+, one Sm3+, and one P5+ atom. In the eleventh O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent Rb1+, one Fe3+, and one P5+ atom. In the twelfth O2- site, O2- is bonded in a distorted linear geometry to one Rb1+, one Sm3+, and one P5+ atom. In the thirteenth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two Rb1+, one Fe3+, and one P5+ atom. In the fourteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Rb1+, one Fe3+, and one P5+ atom. In the fifteenth O2- site, O2- is bonded in a 1-coordinate geometry to two Rb1+, one Sm3+, and one P5+ atom. In the sixteenth O2- site, O2- is bonded in a 2-coordinate geometry to three Rb1+, one Fe3+, and one P5+ atom. In the seventeenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Rb1+, one Fe3+, and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Rb2Mo2P2O11 by Materials Project

Rb2Mo2P2O11 crystallizes in the monoclinic P2_1 space group. The structure is three-dimensional. there are four inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Rb–O bond distances ranging from 3.01–3.44 Å. In the second Rb1+ site, Rb1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Rb–O bond distances ranging from 2.99–3.45 Å. In the third Rb1+ site, Rb1+ is bonded to eight O2- atoms to form distorted RbO8 hexagonal bipyramids that share corners with two MoO6 octahedra, corners with two PO4 tetrahedra, and edges with four MoO6 octahedra. The corner-sharing octahedral tilt angles are 65°. There are a spread of Rb–O bond distances ranging from 2.81–2.97 Å. In the fourth Rb1+ site, Rb1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of Rb–O bond distances ranging from 2.90–3.24 Å. There are four inequivalent Mo5+ sites. In the first Mo5+ site, Mo5+ is bonded to six O2- atoms to form distorted MoO6 octahedra that share a cornercorner with one MoO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one RbO8 hexagonal bipyramid. The corner-sharing octahedral tilt angles are 34°. There are a spread of Mo–O bond distances ranging from 1.74–2.24 Å. In the second Mo5+ site, Mo5+ is bonded to six O2- atoms to form distorted MoO6 octahedra that share a cornercorner with one MoO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one RbO8 hexagonal bipyramid. The corner-sharing octahedral tilt angles are 34°. There are a spread of Mo–O bond distances ranging from 1.74–2.24 Å. In the third Mo5+ site, Mo5+ is bonded to six O2- atoms to form MoO6 octahedra that share a cornercorner with one RbO8 hexagonal bipyramid, a cornercorner with one MoO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one RbO8 hexagonal bipyramid. The corner-sharing octahedral tilt angles are 34°. There are a spread of Mo–O bond distances ranging from 1.75–2.15 Å. In the fourth Mo5+ site, Mo5+ is bonded to six O2- atoms to form MoO6 octahedra that share a cornercorner with one RbO8 hexagonal bipyramid, a cornercorner with one MoO6 octahedra, corners with four PO4 tetrahedra, and an edgeedge with one RbO8 hexagonal bipyramid. The corner-sharing octahedral tilt angles are 34°. There are a spread of Mo–O bond distances ranging from 1.75–2.15 Å. There are four inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four MoO6 octahedra. The corner-sharing octahedra tilt angles range from 41–47°. There is two shorter (1.55 Å) and two longer (1.57 Å) P–O bond length. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four MoO6 octahedra. The corner-sharing octahedra tilt angles range from 41–47°. There are a spread of P–O bond distances ranging from 1.55–1.57 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one RbO8 hexagonal bipyramid and corners with four MoO6 octahedra. The corner-sharing octahedra tilt angles range from 49–51°. There is one shorter (1.55 Å) and three longer (1.56 Å) P–O bond length. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one RbO8 hexagonal bipyramid and corners with four MoO6 octahedra. The corner-sharing octahedra tilt angles range from 49–51°. There is one shorter (1.55 Å) and three longer (1.56 Å) P–O bond length. There are twenty-two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Mo5+ and one P5+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to one Rb1+, one Mo5+, and one P5+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to one Rb1+, one Mo5+, and one P5+ atom. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to one Rb1+, one Mo5+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a 1-coordinate geometry to two Rb1+, one Mo5+, and one P5+ atom. In the sixth O2- site, O2- is bonded in a 1-coordinate geometry to two Rb1+, one Mo5+, and one P5+ atom. In the seventh O2- site, O2- is bonded in a 2-coordinate geometry to one Rb1+, one Mo5+, and one P5+ atom. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to one Rb1+, one Mo5+, and one P5+ atom. In the ninth O2- site, O2- is bonded in a 1-coordinate geometry to two Rb1+, one Mo5+, and one P5+ atom. In the tenth O2- site, O2- is bonded in a 1-coordinate geometry to two Rb1+, one Mo5+, and one P5+ atom. In the eleventh O2- site, O2- is bonded in a 1-coordinate geometry to one Rb1+, one Mo5+, and one P5+ atom. In the twelfth O2- site, O2- is bonded in a 1-coordinate geometry to one Rb1+, one Mo5+, and one P5+ atom. In the thirteenth O2- site, O2- is bonded in a 3-coordinate geometry to two Rb1+, one Mo5+, and one P5+ atom. In the fourteenth O2- site, O2- is bonded in a 3-coordinate geometry to two Rb1+, one Mo5+, and one P5+ atom. In the fifteenth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Rb1+, one Mo5+, and one P5+ atom. In the sixteenth O2- site, O2- is bonded in a 2-coordinate geometry to one Rb1+, one Mo5+, and one P5+ atom. In the seventeenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Rb1+ and two Mo5+ atoms. In the eighteenth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Rb1+ and two Mo5+ atoms. In the nineteenth O2- site, O2- is bonded in a distorted single-bond geometry to three Rb1+ and one Mo5+ atom. In the twentieth O2- site, O2- is bonded in a distorted single-bond geometry to three Rb1+ and one Mo5+ atom. In the twenty-first O2- site, O2- is bonded in a distorted single-bond geometry to two Rb1+ and one Mo5+ atom. In the twenty-second O2- site, O2- is bonded in a distorted single-bond geometry to two Rb1+ and one Mo5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K2RbPt by Materials Project

RbK2Pt crystallizes in the tetragonal P4/mbm space group. The structure is three-dimensional. Rb is bonded in a square co-planar geometry to four Pt atoms. All Rb–Pt bond lengths are 3.84 Å. K is bonded in a water-like geometry to two equivalent Pt atoms. Both K–Pt bond lengths are 3.33 Å. There are two inequivalent Pt sites. In the first Pt site, Pt is bonded in a distorted body-centered cubic geometry to four equivalent Rb and four equivalent K atoms. All Pt–K bond lengths are 3.33 Å. In the second Pt site, Pt is bonded in a distorted body-centered cubic geometry to four equivalent Rb and four equivalent K atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on RbAs4(HO4)3 by Materials Project

Rb(AsO3)2(HAsO2)2HO2 crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of two arsonous acid molecules, one water water molecule, and one Rb(AsO3)2 cluster. In the Rb(AsO3)2 cluster, Rb1+ is bonded in a distorted linear geometry to two O2- atoms. There are one shorter (2.33 Å) and one longer (2.36 Å) Rb–O bond lengths. There are two inequivalent As5+ sites. In the first As5+ site, As5+ is bonded in a 3-coordinate geometry to three O2- atoms. There are a spread of As–O bond distances ranging from 1.34–1.93 Å. In the second As5+ site, As5+ is bonded in a 2-coordinate geometry to three O2- atoms. There are a spread of As–O bond distances ranging from 1.43–2.02 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to one Rb1+ and one As5+ atom. In the second O2- site, O2- is bonded in a distorted L-shaped geometry to one Rb1+ and one As5+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one As5+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one As5+ atom. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to one As5+ atom. In the sixth O2- site, O2- is bonded in a 1-coordinate geometry to one As5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KRb2SiF7 by Materials Project

Rb2KSiF7 crystallizes in the orthorhombic Cmmm space group. The structure is three-dimensional. there are two inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded to six F1- atoms to form distorted RbF6 octahedra that share corners with four SiF6 octahedra and corners with six equivalent RbF6 octahedra. The corner-sharing octahedra tilt angles range from 0–69°. There are a spread of Rb–F bond distances ranging from 2.91–3.04 Å. In the second Rb1+ site, Rb1+ is bonded in a 10-coordinate geometry to ten F1- atoms. There are a spread of Rb–F bond distances ranging from 2.82–3.02 Å. K1+ is bonded in a 10-coordinate geometry to ten F1- atoms. There are a spread of K–F bond distances ranging from 2.78–3.01 Å. There are two inequivalent Si4+ sites. In the first Si4+ site, Si4+ is bonded to six F1- atoms to form SiF6 octahedra that share corners with four equivalent RbF6 octahedra. The corner-sharing octahedral tilt angles are 69°. All Si–F bond lengths are 1.72 Å. In the second Si4+ site, Si4+ is bonded to six F1- atoms to form SiF6 octahedra that share corners with four equivalent RbF6 octahedra. The corner-sharing octahedral tilt angles are 68°. There is two shorter (1.72 Å) and four longer (1.73 Å) Si–F bond length. There are seven inequivalent F1- sites. In the first F1- site, F1- is bonded to four Rb1+ and two equivalent K1+ atoms to form corner-sharing FK2Rb4 octahedra. The corner-sharing octahedra tilt angles range from 0–26°. There are two shorter (2.88 Å) and two longer (2.91 Å) F–Rb bond lengths. Both F–K bond lengths are 2.90 Å. In the second F1- site, F1- is bonded in a distorted single-bond geometry to one Rb1+, two equivalent K1+, and one Si4+ atom. In the third F1- site, F1- is bonded in a distorted single-bond geometry to two equivalent Rb1+, one K1+, and one Si4+ atom. In the fourth F1- site, F1- is bonded in a single-bond geometry to four Rb1+ and one Si4+ atom. In the fifth F1- site, F1- is bonded in a single-bond geometry to two equivalent Rb1+, two equivalent K1+, and one Si4+ atom. In the sixth F1- site, F1- is bonded to four Rb1+ and two equivalent K1+ atoms to form corner-sharing FK2Rb4 octahedra. The corner-sharing octahedra tilt angles range from 0–26°. In the seventh F1- site, F1- is bonded to four Rb1+ and two equivalent K1+ atoms to form corner-sharing FK2Rb4 octahedra. The corner-sharing octahedra tilt angles range from 0–26°. Both F–Rb bond lengths are 2.91 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Rb2Mo(OF2)2 by Materials Project

Rb2MoO2F4 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are two inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded in a 11-coordinate geometry to four equivalent O2- and seven F1- atoms. There are two shorter (3.03 Å) and two longer (3.31 Å) Rb–O bond lengths. There are a spread of Rb–F bond distances ranging from 2.86–3.27 Å. In the second Rb1+ site, Rb1+ is bonded in a 11-coordinate geometry to four equivalent O2- and seven F1- atoms. There are two shorter (3.09 Å) and two longer (3.20 Å) Rb–O bond lengths. There are a spread of Rb–F bond distances ranging from 3.04–3.14 Å. Mo6+ is bonded in an octahedral geometry to two equivalent O2- and four F1- atoms. Both Mo–O bond lengths are 1.82 Å. There are a spread of Mo–F bond distances ranging from 1.94–2.00 Å. O2- is bonded in a distorted single-bond geometry to four Rb1+ and one Mo6+ atom. There are three inequivalent F1- sites. In the first F1- site, F1- is bonded in a 1-coordinate geometry to three Rb1+ and one Mo6+ atom. In the second F1- site, F1- is bonded in a distorted single-bond geometry to three Rb1+ and one Mo6+ atom. In the third F1- site, F1- is bonded in a distorted single-bond geometry to four Rb1+ and one Mo6+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Chronology of alkali anorthosite 14304 clast “b” records basin forming impact at ~3.95 Ga

Alkali-suite rocks constitute one of three major suites of lunar crustal rocks. As such, constraining their formation timescales and petrogenesis is important for understanding the earliest magmatic history of the Moon. However, the magmatic history of alkali-suite rocks is partly obscured by superimposed effects of major basin-forming impact events on the lunar nearside. Consequently, unambiguous crystallization ages of samples from this suite of rocks have not been determined. Here, the aim of this study is to better understand the petrogenetic history of the alkali-suite and the potential superimposed effects of impact metamorphism by determining Sm-Nd, Rb-Sr, and 40 Ar/ 39 Ar ages for an alkali anorthosite clast from Apollo 14 lithic breccia 14304 termed clast “b”. The new chronologic measurements of clast “b” yield concordant Sm-Nd, Rb-Sr, and 40 Ar/ 39 Ar ages of 3947 ± 13 Ma, 3975 ± 34 Ma, and 3937 ± 37 Ma respectively, resulting in a weighted mean age of 3949 ± 11 Ma. This age is not interpreted to date an igneous event related to production of the lunar highlands crust and instead the chronology and petrography of clast “b” are most readily explained by an impact event at ~3.95 Ga that caused near-complete isotopic re-equilibration of the Sm-Nd, Rb-Sr, and 40 Ar/ 39 Ar chronometers. The weighted mean age of 3949 ± 11 Ma of clast “b” is several hundred Ma younger than 4.3–4.4 Ga ages typically determined for samples of other crustal rock suites but in very good agreement with independent estimates for the formation of Imbrium basin ejecta and other marginally older impact events which are thought to have been sampled at the Apollo 14 landing site. Thus, although petrologic and geochemical examination suggest that clast “b” is a pristine igneous clast, its age likely records an impact event at the Apollo 14 landing site. Whereas the various determined ages of clast “b” do not reflect the timescales of alkali-suite magmatism, the relatively low initial Sr and Nd isotopic compositions of clast “b” indicate that its protolith evolved with very low 147 Sm/ 144 Nd and 87 Rb/ 86 Sr that are distinct from estimates for urKREEP but similar to that of lunar plagioclase. This implies that the igneous protolith of clast “b” derived from a plagioclase-dominated KREEP-rich source that must have formed after the formation of the urKREEP source at ~4.35 Ga but well before the impact event recorded by clast “b” at ~3.95 Ga.

58 GEOSCIENCES↗
DOE OSTI2024

Variation in Cation Adsorption Mechanism Controlled by Chemical and Structural Heterogeneities at the Quartz (101)–Water Interface

Mineral–water interfacial reactions are central to chemical processes that control the fate of nutrients and contaminants in natural environments. Mineral surfaces commonly have complex structures and compositions whose impact on interfacial reactivity is poorly understood. Here, in this work, we investigated the effects of surface heterogeneities on Rb + sorption at the quartz (101)–10 mM RbCl solution interface at pH 9.8 using in situ high-resolution X-ray reflectivity. Two surface locales (i.e., Spots A and B) having distinct interfacial structures were chosen: Spot A was characterized by its low defect density (≤20% topmost Si vacancies) and Rb + adsorption occurred predominantly as an inner-sphere complex. In comparison, Spot B had a higher defect density (~50% vacancies) and was covered with poorly crystalline SiO 2 . A substantially larger Rb + uptake (i.e., 7-times higher coverage) was observed on this defective surface where Rb + incorporated in the vacancy sites (confirmed by density functional tight binding-based molecular dynamics simulations) or adsorbed directly on the disordered film. These results provide a direct quantification of how surface heterogeneity influences the geochemical behavior of mineral–water interfaces, in particular highlighting the important role of chemical and structural defects on the sorbate speciation and coverage at silicate mineral surfaces.

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

pH-Driven Restructuring of Hydration Layers and Cation Adsorption at the Alumina–Water Interface

Oxide−water interfaces underpin ion separations, catalysis, and electrochemical energy technologies, where the electrical double layer (EDL) controls adsorption, transport, and reactivity. However, the molecular-scale links between pHdependent surface protonation, hydration-layer structure, and counterion adsorption remain poorly defined. Here, we combine in situ crystal truncation rod (CTR) and resonant anomalous X-ray reflectivity (RAXR) with streaming potential measurements and ab initio molecular dynamics (AIMD) simulations to resolve the chemical and structural evolution of the EDL at the single-crystal alumina (012)−water interface in 10 mM Rb + over pH 3−12. CTR measurements reveal two distinct adsorbed water layers at ∼2.2 and ∼3.5 Å above the surface. Each water layer shifts toward the substrate at transition pHs near 6.5 and 10.6, respectively, reflecting changes in primary hydration layer structure in response to the deprotonation of bridging and terminal aluminol groups. RAXR shows a 10-fold increase in Rb + coverage and a decrease in mean adsorption height from ∼3.5 to ∼2.7 Å with increasing pH, indicating enhanced counterion binding accompanied by Stern layer contraction. Streaming potential measurements demonstrate that the zeta potential, i.e., the potential at the hydrodynamic shear plane, is positive at pH 3 and becomes negative at pH ≥ 3.5. The negative charge magnitude increases with increasing pH, consistent with progressive surface deprotonation at higher pH. AIMD identifies inner- and outer-sphere Rb+ complexes whose adsorption heights and coordination geometries depend sensitively on the protonation state of surface oxygens, providing atomistic support for the experimentally inferred trends. These measurements establish two discrete, site-specific pH transitions in hydration-layer structure that track aluminol (de)protonation and quantitatively link them to a pH-driven contraction of the Stern layer (increasing Rb + coverage and decreasing adsorption height). This provides a direct structural basis for connecting surface acid−base chemistry to ion binding distances at an oxide−water interface.

Adsorption↗
DOE OSTI2025

Model validation and error attribution for a drifting qubit

Qubit performance is often reported in terms of a variety of single-value metrics, each providing a facet of the underlying noise mechanism limiting performance. However, the value of these metrics may drift over long timescales, and reporting a single number for qubit performance fails to account for the low-frequency noise processes that give rise to this drift. Here, in this work, we demonstrate how we can use the distribution of these values to validate or invalidate candidate noise models. We focus on the case of randomized benchmarking (RB), where typically a single error rate is reported but this error rate can drift over time when multiple passes of RB are performed. We show that using a statistical test as simple as the Kolmogorov-Smirnov statistic on the distribution of RB error rates can be used to rule out noise models, assuming the experiment is performed over a long enough time interval to capture relevant low frequency noise. With confidence in a noise model, we show how care must be exercised when performing error attribution using the distribution of drifting RB error rate.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2021

Qutrit Randomized Benchmarking

Ternary quantum processors offer significant potential computational advantages over conventional qubit technologies, leveraging the encoding and processing of quantum information in qutrits (three-level systems). Therefore, to evaluate and compare the performance of such emerging quantum hardware it is essential to have robust benchmarking methods suitable for a higher-dimensional Hilbert space. We demonstrate extensions of industry standard randomized benchmarking (RB) protocols, developed and used extensively for qubits, suitable for ternary quantum logic. Using a superconducting five-qutrit processor, we find an average single-qutrit process infidelity of 3.8×10 -3 . Through interleaved RB, we characterize a few relevant gates, and employ simultaneous RB to fully characterize crosstalk errors. Finally, we apply cycle benchmarking to a two-qutrit CSUM gate and obtain a two-qutrit process fidelity of 0.85. Our results present and demonstrate RB-based tools to characterize the performance of a qutrit processor, and a general approach to diagnose control errors in future qudit hardware.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2023

Genome-wide fitness profiling reveals molecular mechanisms that bacteria use to interact with Trichoderma atroviride exometabolites

Trichoderma spp. are ubiquitous rhizosphere fungi capable of producing several classes of secondary metabolites that can modify the dynamics of the plant-associated microbiome. However, the bacterial-fungal mechanisms that mediate these interactions have not been fully characterized. Here, a random barcode transposon-site sequencing (RB-TnSeq) approach was employed to identify bacterial genes important for fitness in the presence of Trichoderma atroviride exudates. We selected three rhizosphere bacteria with RB-TnSeq mutant libraries that can promote plant growth: the nitrogen fixers Klebsiella michiganensis M5aI and Herbaspirillum seropedicae SmR1, and Pseudomonas simiae WCS417. As a non-rhizosphere species, Pseudomonas putida KT2440 was also included. From the RB-TnSeq data, nitrogen-fixing bacteria competed mainly for iron and required the siderophore transport system TonB/ExbB for optimal fitness in the presence of T . atroviride exudates. In contrast, P . simiae and P . putida were highly dependent on mechanisms associated with membrane lipid modification that are required for resistance to cationic antimicrobial peptides (CAMPs). A mutant in the Hog1-MAP kinase (Δ tmk 3) gene of T . atroviride showed altered expression patterns of many nonribosomal peptide synthetase (NRPS) biosynthetic gene clusters with potential antibiotic activity. In contrast to exudates from wild-type T . atroviride , bacterial mutants containing lesions in genes associated with resistance to antibiotics did not show fitness defects when RB-TnSeq libraries were exposed to exudates from the Δ tmk3 mutant. Unexpectedly, exudates from wild-type T . atroviride and the Δ tmk 3 mutant rescued purine auxotrophic mutants of H . seropedicae , K . michiganensis and P . simiae . Metabolomic analysis on exudates from wild-type T . atroviride and the Δ tmk 3 mutant showed that both strains excrete purines and complex metabolites; functional Tmk3 is required to produce some of these metabolites. This study highlights the complex interplay between Trichoderma -metabolites and soil bacteria, revealing both beneficial and antagonistic effects, and underscoring the intricate and multifaceted nature of this relationship.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2026

pH-Driven Restructuring of Hydration Layers and Cation Ad-sorption at the Alumina-Water Interface

Oxide-water interfaces underpin ion separation, catalysis, and electrochemical energy technologies, where the electrical double layer (EDL) controls adsorption, transport, and reactivity. Yet, the molecular-scale link between pH-dependent surface protonation, hydration-layer structure, and counter-ion adsorption remains poorly defined. Here, we combine in situ crystal truncation rod (CTR) and resonant anomalous X-ray reflectivity (RAXR) with streaming potential measurements and ab initio molecular dynamics (AIMD) simulations to resolve the chemical and structural evolution of the EDL at the single-crystal alumina (012)-water interface in 10 mM Rb+ over pH 3-12. CTR measurements reveal two distinct adsorbed water layers at ~2.2 and ~3.5 Å above the surface that each shift toward the substrate at transition pHs near 6.5 and 10.6, respectively, directly reflecting changes in primary hydration layer structure in response to the deprotonation of bridging and terminal aluminol groups. RAXR shows a 10-fold increase in Rb+ coverage and a decrease in mean adsorption height from ~3.5 to ~2.7 Å with increasing pH, indicating enhanced counter-ion binding accompanied by Stern layer contraction. Streaming potential measurements demonstrate that the zeta potential, i.e., potential at the hydrodynamic shear plane, is positive at pH 3 and becomes negative at pH ≥3.5. This negative charge magnitude increases with increasing pH, consistent with progressive surface deprotonation at higher pH. AIMD identifies inner- and outer-sphere Rb+ complexes whose adsorption heights and coordination geometries depend sensitively on the protonation state of surface oxygens, providing atomistic support for the experimentally inferred trends. These measurements establish two discrete, site-specific pH transitions in hydration-layer structure that track aluminol (de)protonation and quantitatively link them to a pH-driven contraction of the Stern layer (increasing Rb+ coverage and decreasing adsorption height). This provides a direct structural basis for connecting surface acid-base chemistry to ion binding distances at an oxide-water interface.

Electrical double layer (EDL), Surface protonation↗