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At least 865 records · Page 48
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

Probing the dynamics and bottleneck of the key atmospheric SO 2 oxidation reaction by the hydroxyl radical

SO 2 (Sulfur dioxide) is the major precursor to the production of sulfuric acid (H 2 SO 4 ), contributing to acid rain and atmospheric aerosols. Sulfuric acid formed from SO 2 generates light-reflecting sulfate aerosol particles in the atmosphere. This property has prompted recent geoengineering proposals to inject sulfuric acid or its precursors into the Earth’s atmosphere to increase the planetary albedo to counteract global warming. SO 2 oxidation in the atmosphere by the hydroxyl radical HO to form HOSO 2 is a key rate-limiting step in the mechanism for forming acid rain. However, the dynamics of the HO + SO 2 → HOSO 2 reaction and its slow rate in the atmosphere are poorly understood to date. Herein, we use photoelectron spectroscopy of cryogenically cooled HOSO 2 – anion to access the neutral HOSO 2 radical near the transition state of the HO + SO 2 reaction. Spectroscopic and dynamic calculations are conducted on the first ab initio-based full-dimensional potential energy surface to interpret the photoelectron spectra of HOSO 2 – and to probe the dynamics of the HO + SO 2 reaction. In addition to the finding of a unique pre-reaction complex (HO⋯SO 2 ) directly connected to the transition state, dynamic calculations reveal that the accessible phase space for the HO + SO 2 → HOSO 2 reaction is extremely narrow, forming a key reaction bottleneck and slowing the reaction rate in the atmosphere, despite the low reaction barrier. This study underlines the importance of understanding the full multidimensional potential energy surface to elucidate the dynamics of complex bimolecular reactions involving polyatomic reactants.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Materials Data on HoGaNi by Materials Project

HoNiGa crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Ho is bonded in a 1-coordinate geometry to five equivalent Ni and six equivalent Ga atoms. There are a spread of Ho–Ni bond distances ranging from 2.81–3.06 Å. There are a spread of Ho–Ga bond distances ranging from 2.99–3.11 Å. Ni is bonded in a 9-coordinate geometry to five equivalent Ho and four equivalent Ga atoms. There are a spread of Ni–Ga bond distances ranging from 2.51–2.64 Å. Ga is bonded in a 10-coordinate geometry to six equivalent Ho and four equivalent Ni atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HoSnPd by Materials Project

HoPdSn crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Ho is bonded in a 12-coordinate geometry to six equivalent Pd and six equivalent Sn atoms. There are a spread of Ho–Pd bond distances ranging from 3.10–3.39 Å. There are a spread of Ho–Sn bond distances ranging from 3.20–3.33 Å. Pd is bonded in a 10-coordinate geometry to six equivalent Ho and four equivalent Sn atoms. There are a spread of Pd–Sn bond distances ranging from 2.69–2.89 Å. Sn is bonded in a 10-coordinate geometry to six equivalent Ho and four equivalent Pd atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HoCdCu4 by Materials Project

HoCu4Cd is Hexagonal Laves-derived structured and crystallizes in the cubic F-43m space group. The structure is three-dimensional. Ho is bonded in a 12-coordinate geometry to twelve equivalent Cu and four equivalent Cd atoms. All Ho–Cu bond lengths are 2.99 Å. All Ho–Cd bond lengths are 3.12 Å. Cu is bonded to three equivalent Ho, six equivalent Cu, and three equivalent Cd atoms to form a mixture of edge, corner, and face-sharing CuHo3Cd3Cu6 cuboctahedra. There are three shorter (2.53 Å) and three longer (2.56 Å) Cu–Cu bond lengths. All Cu–Cd bond lengths are 2.98 Å. Cd is bonded in a 4-coordinate geometry to four equivalent Ho and twelve equivalent Cu atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho2InGe2 by Materials Project

Ho2InGe2 crystallizes in the tetragonal P4/mbm space group. The structure is three-dimensional. Ho is bonded in a 6-coordinate geometry to four equivalent In and six equivalent Ge atoms. All Ho–In bond lengths are 3.43 Å. There are two shorter (2.96 Å) and four longer (3.07 Å) Ho–Ge bond lengths. In is bonded to eight equivalent Ho and four equivalent Ge atoms to form a mixture of corner and face-sharing InHo8Ge4 cuboctahedra. All In–Ge bond lengths are 2.94 Å. Ge is bonded in a 9-coordinate geometry to six equivalent Ho, two equivalent In, and one Ge atom. The Ge–Ge bond length is 2.56 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HoMg2Cu9 by Materials Project

Mg2HoCu9 crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Mg is bonded in a 12-coordinate geometry to twelve Cu atoms. There are a spread of Mg–Cu bond distances ranging from 2.89–2.93 Å. Ho is bonded in a distorted hexagonal planar geometry to eighteen Cu atoms. There are six shorter (2.88 Å) and twelve longer (3.23 Å) Ho–Cu bond lengths. There are four inequivalent Cu sites. In the first Cu site, Cu is bonded in a 12-coordinate geometry to three equivalent Ho and nine Cu atoms. There are six shorter (2.50 Å) and three longer (2.88 Å) Cu–Cu bond lengths. In the second Cu site, Cu is bonded to three equivalent Mg, two equivalent Ho, and seven Cu atoms to form a mixture of edge, corner, and face-sharing CuHo2Mg3Cu7 cuboctahedra. There are a spread of Cu–Cu bond distances ranging from 2.47–2.52 Å. In the third Cu site, Cu is bonded in a 12-coordinate geometry to three equivalent Ho and nine Cu atoms. In the fourth Cu site, Cu is bonded to six equivalent Mg and six equivalent Cu atoms to form CuMg6Cu6 cuboctahedra that share corners with twelve equivalent CuHo2Mg3Cu7 cuboctahedra, edges with six equivalent CuMg6Cu6 cuboctahedra, and faces with eighteen equivalent CuHo2Mg3Cu7 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HoGeAu by Materials Project

HoAuGe is half-Heusler structured and crystallizes in the cubic F-43m space group. The structure is three-dimensional. Ho is bonded to four equivalent Au and six equivalent Ge atoms to form a mixture of distorted corner and face-sharing HoGe6Au4 tetrahedra. All Ho–Au bond lengths are 2.82 Å. All Ho–Ge bond lengths are 3.26 Å. Au is bonded in a body-centered cubic geometry to four equivalent Ho and four equivalent Ge atoms. All Au–Ge bond lengths are 2.82 Å. Ge is bonded in a 4-coordinate geometry to six equivalent Ho and four equivalent Au atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HoMn12 by Materials Project

HoMn12 crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. Ho is bonded in a 12-coordinate geometry to twenty Mn atoms. There are twelve shorter (3.02 Å) and eight longer (3.15 Å) Ho–Mn bond lengths. There are three inequivalent Mn sites. In the first Mn site, Mn is bonded to two equivalent Ho and ten Mn atoms to form a mixture of distorted edge, corner, and face-sharing MnHo2Mn10 cuboctahedra. There are a spread of Mn–Mn bond distances ranging from 2.38–2.68 Å. In the second Mn site, Mn is bonded to two equivalent Ho and ten Mn atoms to form a mixture of edge, corner, and face-sharing MnHo2Mn10 cuboctahedra. There are two shorter (2.35 Å) and four longer (2.56 Å) Mn–Mn bond lengths. In the third Mn site, Mn is bonded in a 1-coordinate geometry to one Ho and thirteen Mn atoms. There are one shorter (2.23 Å) and four longer (2.83 Å) Mn–Mn bond lengths.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HoAl2Ni by Materials Project

HoNiAl2 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Ho is bonded in a 1-coordinate geometry to three equivalent Ni and ten equivalent Al atoms. There are one shorter (2.81 Å) and two longer (3.03 Å) Ho–Ni bond lengths. There are a spread of Ho–Al bond distances ranging from 3.06–3.28 Å. Ni is bonded in a 9-coordinate geometry to three equivalent Ho and six equivalent Al atoms. There are two shorter (2.46 Å) and four longer (2.51 Å) Ni–Al bond lengths. Al is bonded in a 3-coordinate geometry to five equivalent Ho and three equivalent Ni atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HoAl7Au3 by Materials Project

HoAu3Al7 crystallizes in the trigonal R-3c space group. The structure is three-dimensional. Ho is bonded in a 6-coordinate geometry to six equivalent Au and twelve equivalent Al atoms. All Ho–Au bond lengths are 3.25 Å. There are six shorter (3.32 Å) and six longer (3.37 Å) Ho–Al bond lengths. Au is bonded in a 9-coordinate geometry to two equivalent Ho and seven Al atoms. There are a spread of Au–Al bond distances ranging from 2.59–2.67 Å. There are two inequivalent Al sites. In the first Al site, Al is bonded in a distorted trigonal planar geometry to two equivalent Ho and three equivalent Au atoms. In the second Al site, Al is bonded in a trigonal planar geometry to three equivalent Au atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HoCuPb by Materials Project

HoCuPb crystallizes in the hexagonal P6_3mc space group. The structure is three-dimensional. Ho is bonded in a 12-coordinate geometry to three equivalent Cu and six equivalent Pb atoms. All Ho–Cu bond lengths are 2.94 Å. There are three shorter (3.16 Å) and three longer (3.31 Å) Ho–Pb bond lengths. Cu is bonded in a 10-coordinate geometry to three equivalent Ho and four equivalent Pb atoms. There are three shorter (2.76 Å) and one longer (2.95 Å) Cu–Pb bond lengths. Pb is bonded in a 10-coordinate geometry to six equivalent Ho and four equivalent Cu atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HoMnSi by Materials Project

HoMnSi crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Ho is bonded in a 5-coordinate geometry to six equivalent Mn and five equivalent Si atoms. There are a spread of Ho–Mn bond distances ranging from 2.96–3.32 Å. There are two shorter (2.91 Å) and three longer (2.96 Å) Ho–Si bond lengths. Mn is bonded in a 4-coordinate geometry to six equivalent Ho and four equivalent Si atoms. There are three shorter (2.47 Å) and one longer (2.71 Å) Mn–Si bond lengths. Si is bonded in a 9-coordinate geometry to five equivalent Ho and four equivalent Mn atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HoSiRh by Materials Project

HoRhSi crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Ho is bonded in a 9-coordinate geometry to six equivalent Rh and five equivalent Si atoms. There are a spread of Ho–Rh bond distances ranging from 2.96–3.31 Å. There are a spread of Ho–Si bond distances ranging from 2.97–3.00 Å. Rh is bonded in a 10-coordinate geometry to six equivalent Ho and four equivalent Si atoms. There are a spread of Rh–Si bond distances ranging from 2.48–2.60 Å. Si is bonded in a 9-coordinate geometry to five equivalent Ho and four equivalent Rh atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HoGeIr by Materials Project

HoIrGe crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Ho is bonded in a 11-coordinate geometry to six equivalent Ir and five equivalent Ge atoms. There are a spread of Ho–Ir bond distances ranging from 3.03–3.29 Å. There are two shorter (2.98 Å) and three longer (3.02 Å) Ho–Ge bond lengths. Ir is bonded in a 10-coordinate geometry to six equivalent Ho and four equivalent Ge atoms. There are three shorter (2.56 Å) and one longer (2.63 Å) Ir–Ge bond lengths. Ge is bonded in a 9-coordinate geometry to five equivalent Ho and four equivalent Ir atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HoGeRu by Materials Project

HoRuGe crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Ho is bonded in a 9-coordinate geometry to four equivalent Ru and six equivalent Ge atoms. There are a spread of Ho–Ru bond distances ranging from 2.94–3.00 Å. There are a spread of Ho–Ge bond distances ranging from 3.04–3.30 Å. Ru is bonded in a 8-coordinate geometry to four equivalent Ho and four equivalent Ge atoms. There are a spread of Ru–Ge bond distances ranging from 2.54–2.59 Å. Ge is bonded in a 10-coordinate geometry to six equivalent Ho and four equivalent Ru atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HoSiIr by Materials Project

HoIrSi crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Ho is bonded in a 11-coordinate geometry to six equivalent Ir and five equivalent Si atoms. There are a spread of Ho–Ir bond distances ranging from 2.99–3.28 Å. There are a spread of Ho–Si bond distances ranging from 2.94–3.00 Å. Ir is bonded in a 10-coordinate geometry to six equivalent Ho and four equivalent Si atoms. There are a spread of Ir–Si bond distances ranging from 2.48–2.58 Å. Si is bonded in a 9-coordinate geometry to five equivalent Ho and four equivalent Ir atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HoGeRh by Materials Project

HoRhGe crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Ho is bonded in a 11-coordinate geometry to six equivalent Rh and five equivalent Ge atoms. There are a spread of Ho–Rh bond distances ranging from 3.01–3.34 Å. There are a spread of Ho–Ge bond distances ranging from 3.00–3.02 Å. Rh is bonded in a 10-coordinate geometry to six equivalent Ho and four equivalent Ge atoms. There are a spread of Rh–Ge bond distances ranging from 2.56–2.64 Å. Ge is bonded in a 9-coordinate geometry to five equivalent Ho and four equivalent Rh atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ho6Fe23 by Materials Project

Ho6Fe23 crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Ho is bonded in a 12-coordinate geometry to twelve Fe atoms. There are a spread of Ho–Fe bond distances ranging from 2.89–3.03 Å. There are four inequivalent Fe sites. In the first Fe site, Fe is bonded in a 10-coordinate geometry to three equivalent Ho and ten Fe atoms. There are a spread of Fe–Fe bond distances ranging from 2.52–2.91 Å. In the second Fe site, Fe is bonded in a body-centered cubic geometry to eight equivalent Fe atoms. In the third Fe site, Fe is bonded to four equivalent Ho and eight Fe atoms to form a mixture of face and corner-sharing FeHo4Fe8 cuboctahedra. All Fe–Fe bond lengths are 2.45 Å. In the fourth Fe site, Fe is bonded in a distorted q6 geometry to three equivalent Ho and nine Fe atoms. All Fe–Fe bond lengths are 2.53 Å.

36 MATERIALS SCIENCE↗