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Materials Data on Cd(CO2)2 by Materials Project

CdC2O4 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Cd2+ is bonded to six O2- atoms to form corner-sharing CdO6 octahedra. The corner-sharing octahedral tilt angles are 56°. There are a spread of Cd–O bond distances ranging from 2.26–2.45 Å. C3+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.26 Å) and one longer (1.28 Å) C–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cd2+ and one C3+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Cd2+ and one C3+ atom.

36 MATERIALS SCIENCE↗

Materials Data on CdH2(CO2)2 by Materials Project

Cd(HCOO)2 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Cd2+ is bonded to seven O2- atoms to form distorted edge-sharing CdO7 pentagonal bipyramids. There are a spread of Cd–O bond distances ranging from 2.32–2.65 Å. There are two inequivalent C2+ sites. In the first C2+ site, C2+ is bonded in a trigonal planar geometry to one H1+ and two O2- atoms. The C–H bond length is 1.10 Å. There is one shorter (1.26 Å) and one longer (1.28 Å) C–O bond length. In the second C2+ site, C2+ is bonded in a trigonal planar geometry to one H1+ and two O2- atoms. The C–H bond length is 1.11 Å. Both C–O bond lengths are 1.27 Å. There are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one C2+ atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one C2+ atom. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Cd2+ and one C2+ atom. In the second O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cd2+ and one C2+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Cd2+ and one C2+ atom. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Cd2+ and one C2+ atom.

36 MATERIALS SCIENCE↗

Materials Data on CdC2(NO)4 by Materials Project

Cd(N2)2(CO2)2 is Cyanogen Chloride-derived structured and crystallizes in the orthorhombic P2_12_12 space group. The structure is zero-dimensional and consists of two cadmium molecules, four carbon dioxide molecules, and four nitrogen molecules.

36 MATERIALS SCIENCE↗

Materials Data on CdHC2(NO)4 by Materials Project

(Cd)2(N2)4(CO2)4H2 is Cyanogen Chloride-derived structured and crystallizes in the orthorhombic Pbcn space group. The structure is zero-dimensional and consists of four cadmium molecules, eight carbon dioxide molecules, four hydrogen molecules, and eight nitrogen molecules.

36 MATERIALS SCIENCE↗

Materials Data on Cd3Co2(CN)12 by Materials Project

Cd(CoCd(CN)6)2 is alpha Rhenium trioxide-derived structured and crystallizes in the tetragonal P-4m2 space group. The structure is three-dimensional and consists of one cadmium molecule and one CoCd(CN)6 framework. In the CoCd(CN)6 framework, there are two inequivalent Co2+ sites. In the first Co2+ site, Co2+ is bonded in an octahedral geometry to six C+2.17+ atoms. All Co–C bond lengths are 1.87 Å. In the second Co2+ site, Co2+ is bonded in an octahedral geometry to six C+2.17+ atoms. All Co–C bond lengths are 1.87 Å. Cd2+ is bonded in an octahedral geometry to six N3- atoms. There are a spread of Cd–N bond distances ranging from 2.27–2.41 Å. There are three inequivalent C+2.17+ sites. In the first C+2.17+ site, C+2.17+ is bonded in a linear geometry to one Co2+ and one N3- atom. The C–N bond length is 1.17 Å. In the second C+2.17+ site, C+2.17+ is bonded in a linear geometry to one Co2+ and one N3- atom. The C–N bond length is 1.17 Å. In the third C+2.17+ site, C+2.17+ is bonded in a linear geometry to one Co2+ and one N3- atom. The C–N bond length is 1.17 Å. There are three inequivalent N3- sites. In the first N3- site, N3- is bonded in a linear geometry to one Cd2+ and one C+2.17+ atom. In the second N3- site, N3- is bonded in a linear geometry to one Cd2+ and one C+2.17+ atom. In the third N3- site, N3- is bonded in a linear geometry to one Cd2+ and one C+2.17+ atom.

36 MATERIALS SCIENCE↗

BOREAS TE-9 NSA Photosynthetic Response Data

The Boreal Ecosystem-Atmospheric Study (BOREAS) TE-9 (Terrestrial Ecology) team collected several data sets related to chemical and photosynthetic properties of leaves. This data set describes: (1) the response of leaf and shoot-level photosynthesis to ambient and intercellular CO2 concentration, temperature, and incident photosynthetically active radiation (PAR) for black spruce, jack pine, and aspen during the three intensive field campaigns (IFCs) in 1994 in the Northern Study Area (NSA); (2) the response of stomatal conductance to vapor pressure difference throughout the growing season of 1994; and (3) a range of shoot water potentials (controlled in the laboratory) for black spruce and jack pine. The data are stored in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

Hall, Forrest G.↗

Boosting CO 2 Electrochemical Reduction with Atomically Precise Surface Modification on Gold Nanoclusters

Thiolate-protected gold nanoclusters (NCs) are promising catalytic materials for the electrochemical CO 2 reduction reaction (CO 2 RR). In this work an atomic level modification of a Au 23 NC is made by substituting two surface Au atoms with two Cd atoms, and it enhances the CO 2 RR selectivity to 90–95 % at the applied potential between -0.5 to -0.9 V, which is doubled compared to that of the undoped Au 23 . Additionally, the Cd-doped Au 19 Cd 2 exhibits the highest CO 2 RR activity (2200 mA mg -1 at -1.0 V vs. RHE) among the reported NCs. This synergetic effect between Au and Cd is remarkable. Density-functional theory calculations reveal that the exposure of a sulfur active site upon partial ligand removal provides an energetically feasible CO 2 RR pathway. The thermodynamic energy barrier for CO formation is 0.74 eV lower on Au 19 Cd 2 than on Au 23 . Here these results reveal that Cd doping can boost the CO 2 RR performance of Au NCs by modifying the surface geometry and electronic structure, which further changes the intermediate binding energy. This work offers insights into the surface doping mechanism of the CO 2 RR and bimetallic synergism.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗

Materials Data on Mg30CdCoO32 by Materials Project

Mg30CoCdO32 is alpha Po-derived structured and crystallizes in the tetragonal P4/mmm space group. The structure is three-dimensional. there are eight inequivalent Mg2+ sites. In the first Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with two equivalent CoO6 octahedra, corners with four MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.12 Å) and two longer (2.14 Å) Mg–O bond lengths. In the second Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with two equivalent CdO6 octahedra, corners with four MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.02 Å) and four longer (2.16 Å) Mg–O bond lengths. In the third Mg2+ site, Mg2+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Mg–O bond lengths are 2.14 Å. In the fourth Mg2+ site, Mg2+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are four shorter (2.12 Å) and two longer (2.15 Å) Mg–O bond lengths. In the fifth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, an edgeedge with one CoO6 octahedra, an edgeedge with one CdO6 octahedra, and edges with ten MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–6°. There are a spread of Mg–O bond distances ranging from 2.13–2.17 Å. In the sixth Mg2+ site, Mg2+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are five shorter (2.14 Å) and one longer (2.15 Å) Mg–O bond lengths. In the seventh Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, an edgeedge with one CoO6 octahedra, and edges with eleven MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. There are four shorter (2.14 Å) and two longer (2.15 Å) Mg–O bond lengths. In the eighth Mg2+ site, Mg2+ is bonded to six O2- atoms to form MgO6 octahedra that share corners with six MgO6 octahedra, an edgeedge with one CdO6 octahedra, and edges with eleven MgO6 octahedra. The corner-sharing octahedra tilt angles range from 0–6°. There are a spread of Mg–O bond distances ranging from 2.12–2.16 Å. Co2+ is bonded to six O2- atoms to form CoO6 octahedra that share corners with two equivalent CdO6 octahedra, corners with four equivalent MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.07 Å) and four longer (2.16 Å) Co–O bond lengths. Cd2+ is bonded to six O2- atoms to form CdO6 octahedra that share corners with two equivalent CoO6 octahedra, corners with four equivalent MgO6 octahedra, and edges with twelve MgO6 octahedra. The corner-sharing octahedral tilt angles are 0°. There are two shorter (2.22 Å) and four longer (2.26 Å) Cd–O bond lengths. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded to five Mg2+ and one Co2+ atom to form a mixture of corner and edge-sharing OMg5Co octahedra. The corner-sharing octahedra tilt angles range from 0–3°. In the second O2- site, O2- is bonded to five Mg2+ and one Cd2+ atom to form OMg5Cd octahedra that share corners with six OMg5Co octahedra and edges with twelve OMg5Cd octahedra. The corner-sharing octahedra tilt angles range from 0–3°. In the third O2- site, O2- is bonded to six Mg2+ atoms to form a mixture of corner and edge-sharing OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°. In the fourth O2- site, O2- is bonded to six Mg2+ atoms to form a mixture of corner and edge-sharing OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–3°. In the fifth O2- site, O2- is bonded to five Mg2+ and one Cd2+ atom to form OMg5Cd octahedra that share corners with six OMg5Co octahedra and edges with twelve OMg5Cd octahedra. The corner-sharing octahedra tilt angles range from 0–3°. There are two shorter (2.16 Å) and two longer (2.17 Å) O–Mg bond lengths. In the sixth O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six equivalent OMg6 octahedra and edges with twelve OMg5Co octahedra. The corner-sharing octahedra tilt angles range from 0–2°. In the seventh O2- site, O2- is bonded to four equivalent Mg2+, one Co2+, and one Cd2+ atom to form OMg4CdCo octahedra that share corners with six OMg4CdCo octahedra and edges with twelve OMg5Co octahedra. The corner-sharing octahedra tilt angles range from 0–2°. In the eighth O2- site, O2- is bonded to six Mg2+ atoms to form OMg6 octahedra that share corners with six OMg4CdCo octahedra and edges with twelve OMg5Co octahedra. The corner-sharing octahedra tilt angles range from 0–2°. In the ninth O2- site, O2- is bonded to six Mg2+ atoms to form a mixture of corner and edge-sharing OMg6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°.

36 MATERIALS SCIENCE↗

BOREAS TE-9 In Situ Diurnal Gas Exchange of NAS Boreal Forest Stands

The BOREAS TE-9 team collected several data sets related to chemical and photosynthetic properties of leaves in boreal forest tree species. The purpose of the BOREAS TE-09 study was threefold: 1) to provide in situ gas exchange data that will be used to validate models of photosynthetic responses to light, temperature, and carbon dioxide (CO2); 2) to compare the photosynthetic responses of different tree crown levels (upper and lower); and 3) to characterize the diurnal water potential curves for these sites to get an indication of the extent to which soil moisture supply to leaves might be limiting photosynthesis. The gas exchange data of the BOREAS NSA were collected to characterize diurnal gas exchange and water potential of two canopy levels of five boreal canopy cover types: young jack pine, old jack pine, old aspen, lowland old black spruce, and upland black spruce. These data were collected between 27-May-1994 and 17-Sep-1994. The data are provided in tabular ASCII files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

Hall, Forrest G.↗

BOREAS AFM-2 Wyoming King Air 1994 Aircraft Sounding Data

The BOREAS AFM-2 team used the University of Wyoming King Air aircraft during IFCs 1, 2, and 3 in 1994 to collected pass-by-pass fluxes (and many other statistics) for the large number of level (constant altitude), straight-line passes used in a variety of flight patterns over the SSA and NSA and areas along the transect between these study areas. The data described here form a second set, namely soundings that were incorporated into nearly every research flight by the King Air in 1994. These soundings generally went from near the surface to above the inversion layer. Most were flown immediately after takeoff or immediately after finishing the last flux pattern of that particular day's flights. The parameters that were measured include wind direction, wind speed, west wind component (u), south wind component (v), static pressure, air dry bulb temperature, potential temperature, dewpoint, temperature, water vapor mixing ratio, and CO2 concentration. Data on the aircraft's location, attitude, and altitude during data collection are also provided. These data are stored in tabular ASCH files. The data files are available on a CD-ROM (see document number 20010000884) or from the Oak Ridge National Laboratory (ORNL) Distributed Active Archive Center (DAAC).

Kelly, Robert D.↗

Molecular Coatings Improve the Selectivity and Durability of CO 2 Reduction Chalcogenide Photocathodes

The quest for solar-driven conversion of carbon dioxide to chemicals and fuels hinges upon the identification of an efficient, durable, and selective photocathode. Chalcogenide p-type semiconductors exemplified by chalcopyrite Cu(In,Ga)Se 2 (CIGS) have been effectively deployed as photocathodes. However, selectivity toward CO 2 reduction and durability of the commonly used CdS adlayer remain primary challenges. Here, we demonstrate that for the wide band gap CuGa 3 Se 5 chalcopyrite absorber these challenges are well addressed by an organic coating generated in situ from an N,N'-(1,4-phenylene)bispyridinium ditriflate salt in the electrolyte. The molecular additive provides a 30-fold increase in selectivity toward CO2R products compared to the unmodified system and lowers Cd corrosion at least 10-fold. This dual functionality highlights the promise of hybrid solid-state-molecular photocathodes for enabling durable and efficient solar fuel systems.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

Measurements of NH3 absorption coefficients with a C-13/O-16/2 laser

Measurements of NH3 absorption coefficients are presented for several transitions of a C-13(O-16)2 laser for small concentrations of NH3(p less than 1 torr) for absorption lines broadened to 1 atm with N2. NH3 absorption coefficients were determined for laser transitions R(8)(920.2194 wavelengths/cm) to R(28)(933.8808 wavelengths/cm) of the 00 1 - (10 0,02 0)I band. The strongest absorption coefficient K = 36.09 + or - 1.43 per (atm-cm) was measured for the R(18) transition for the NH3 line, aQ(6,6), and is larger than has been found in any previous measurements with a CO2 laser. The dependence of K on total pressure was also obtained for select transitions, and the frequency separation between the R(18) laser transition and the neighboring NH3 line aQ(6,6) was determined to be 550 + or - 50 MHz. These results are significant for long path absorption monitoring of NH3 with CO2 lasers since the path length can be reduced by approximately 40% and for heterodyne detection of NH3 since the relative position of the laser transition to the NH3 absorption line is well within the bandpass of Hg-Cd-Te photomixers.

Allario, F.↗

Utilization of ammonium as a nitrogen source: effects of ambient acidity on growth and nitrogen accumulation by soybean

Dry matter accumulation of plants utilizing NH4+ as the sole nitrogen source generally is less than that of plants receiving NO3- unless acidity of the root-zone is controlled at a pH of about 6.0. To test the hypothesis that the reduction in growth is a consequence of nitrogen stress within the plant in response to effects of increased acidity during uptake of NH4+ by roots, nonnodulated soybean plants (Glycine max [L.] Merr. cv Ransom) were grown for 24 days in flowing nutrient culture containing 1.0 millimolar NH4+ as the nitrogen source. Acidities of the culture solutions were controlled at pH 6.1, 5.1, and 4.1 +/- 0.1 by automatic additions of 0.01 N H2SO4 or Ca(OH)2. Plants were sampled at intervals of 3 to 4 days for determination of dry matter and nitrogen accumulation. Rates of NH4+ uptake per gram root dry weight were calculated from these data. Net CO2 exchange rates per unit leaf area were measured on attached leaves by infrared gas analysis. When acidity of the culture solution was increased from pH 6.1 to 5.1, dry matter and nitrogen accumulation were reduced by about 40% within 14 days. Net CO2 exchange rates per unit leaf area, however, were not affected, and the decreased growth was associated with a reduction in rates of appearance and expansion of new leaves. The uptake rates of NH4+ per gram root were about 25% lower throughout the 24 days at pH 5.1 than at 6.1. A further increase in solution acidity from pH 5.1 to 4.1 resulted in cessation of net dry matter production and appearance of new leaves within 10 days. Net CO2 exchange rates per unit leaf area declined rapidly until all viable leaves had abscised by 18 days. Uptake rates of NH4+, which were initially about 50% lower at pH 4.1 than at 6.1 continued to decline with time of exposure until net uptake ceased at 10 days. Since these responses also are characteristic of the sequence of responses that occur during onset and progression of a nitrogen stress, they corroborate our hypothesis.

NASA Discipline Number 61-10↗