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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on VH14SO11 by Materials Project

V(H2O)6H2OSO4 crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four sulfuric acid molecules, four water molecules, and four V(H2O)6 clusters. In two of the V(H2O)6 clusters, V2+ is bonded in an octahedral geometry to six O2- atoms. There are a spread of V–O bond distances ranging from 2.16–2.19 Å. There are six inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted water-like geometry to one V2+ and two H1+ atoms. In the second O2- site, O2- is bonded in a distorted water-like geometry to one V2+ and two H1+ atoms. In the third O2- site, O2- is bonded in a distorted water-like geometry to one V2+ and two H1+ atoms. In two of the V(H2O)6 clusters, V2+ is bonded in an octahedral geometry to six O2- atoms. There are four shorter (2.16 Å) and two longer (2.23 Å) V–O bond lengths. There are six inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a distorted single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. In the second H1+ site, H1+ is bonded in a distorted single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted water-like geometry to one V2+ and two H1+ atoms. In the second O2- site, O2- is bonded in a distorted water-like geometry to one V2+ and two H1+ atoms. In the third O2- site, O2- is bonded in a distorted water-like geometry to one V2+ and two H1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NaH9O5 by Materials Project

(Na(H2O)3)2H2O2(H2O)2 crystallizes in the monoclinic C2 space group. The structure is one-dimensional and consists of four water molecules; four water molecules; and two Na(H2O)3 ribbons oriented in the (0, 1, 0) direction. In each Na(H2O)3 ribbon, Na1+ is bonded to five O2- atoms to form a mixture of edge and corner-sharing NaO5 trigonal bipyramids. There are a spread of Na–O bond distances ranging from 2.37–2.41 Å. There are six inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a distorted single-bond geometry to one O2- atom. The H–O bond length is 1.01 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted water-like geometry to one Na1+ and two H1+ atoms. In the second O2- site, O2- is bonded in a distorted water-like geometry to two equivalent Na1+ and two H1+ atoms. In the third O2- site, O2- is bonded in a distorted water-like geometry to two equivalent Na1+ and two H1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on H5BrO2 by Materials Project

(H2O)2HBr crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of two (H2O)2HBr clusters. In one of the (H2O)2HBr clusters, there are fifteen inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. In the second H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.14 Å) and one longer (1.29 Å) H–O bond length. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- and one Br1- atom. The H–O bond length is 1.01 Å. The H–Br bond length is 2.18 Å. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one O2- and one Br1- atom. The H–O bond length is 1.02 Å. The H–Br bond length is 2.15 Å. In the sixth H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.11 Å) and one longer (1.34 Å) H–O bond length. In the seventh H1+ site, H1+ is bonded in a single-bond geometry to one O2- and one Br1- atom. The H–O bond length is 1.01 Å. The H–Br bond length is 2.17 Å. In the eighth H1+ site, H1+ is bonded in a single-bond geometry to one O2- and one Br1- atom. The H–O bond length is 1.00 Å. The H–Br bond length is 2.26 Å. In the ninth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the tenth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the eleventh H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the twelfth H1+ site, H1+ is bonded in a single-bond geometry to one O2- and one Br1- atom. The H–O bond length is 0.99 Å. The H–Br bond length is 2.29 Å. In the thirteenth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the fourteenth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the fifteenth H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.14 Å) and one longer (1.29 Å) H–O bond length. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal non-coplanar geometry to three H1+ atoms. In the second O2- site, O2- is bonded in a trigonal non-coplanar geometry to three H1+ atoms. In the third O2- site, O2- is bonded in a trigonal non-coplanar geometry to three H1+ atoms. In the fourth O2- site, O2- is bonded in a trigonal planar geometry to three H1+ atoms. In the fifth O2- site, O2- is bonded in a trigonal planar geometry to three H1+ atoms. In the sixth O2- site, O2- is bonded in a trigonal planar geometry to three H1+ atoms. There are three inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a distorted single-bond geometry to one H1+ atom. In the second Br1- site, Br1- is bonded in a 1-coordinate geometry to one H1+ atom. In the third Br1- site, Br1- is bonded in a 1-coordinate geometry to three H1+ atoms. In one of the (H2O)2HBr clusters, there are five inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- and one Br1- atom. The H–O bond length is 1.02 Å. The H–Br bond length is 2.10 Å. In the third H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.13 Å) and one longer (1.31 Å) H–O bond length. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal non-coplanar geometry to three H1+ atoms. In the second O2- site, O2- is bonded in a trigonal planar geometry to three H1+ atoms. Br1- is bonded in a distorted single-bond geometry to one H1+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ReH3O5 by Materials Project

H(ReO4)H2O crystallizes in the triclinic P1 space group. The structure is zero-dimensional and consists of two H(ReO4)H2O clusters. In one of the H(ReO4)H2O clusters, Re7+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of Re–O bond distances ranging from 1.73–1.82 Å. There are three inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the third H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.12 Å) and one longer (1.32 Å) H–O bond length. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to three H1+ atoms. In the second O2- site, O2- is bonded in a single-bond geometry to one Re7+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one Re7+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Re7+ and one H1+ atom. In the fifth O2- site, O2- is bonded in a single-bond geometry to one Re7+ atom. In one of the H(ReO4)H2O clusters, Re7+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of Re–O bond distances ranging from 1.74–1.79 Å. There are three inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the third H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.16 Å) and one longer (1.22 Å) H–O bond length. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal planar geometry to three H1+ atoms. In the second O2- site, O2- is bonded in a single-bond geometry to one Re7+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one Re7+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Re7+ and one H1+ atom. In the fifth O2- site, O2- is bonded in a single-bond geometry to one Re7+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ReH3O5 by Materials Project

H(ReO4)H2O crystallizes in the triclinic P1 space group. The structure is one-dimensional and consists of two H(ReO4)H2O ribbons oriented in the (0, 0, 1) and (1, 0, 1) directions. In one of the H(ReO4)H2O ribbons, Re7+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of Re–O bond distances ranging from 1.74–1.77 Å. There are three inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the second H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.05 Å) and one longer (1.45 Å) H–O bond length. In the third H1+ site, H1+ is bonded in a distorted linear geometry to two O2- atoms. There is one shorter (1.02 Å) and one longer (1.61 Å) H–O bond length. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal non-coplanar geometry to three H1+ atoms. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to one Re7+ and one H1+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one Re7+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one Re7+ atom. In the fifth O2- site, O2- is bonded in a bent 150 degrees geometry to one Re7+ and one H1+ atom. In one of the H(ReO4)H2O ribbons, Re7+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of Re–O bond distances ranging from 1.73–1.78 Å. There are three inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the second H1+ site, H1+ is bonded in a distorted 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 third H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.04 Å) and one longer (1.47 Å) H–O bond length. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a trigonal non-coplanar geometry to three H1+ atoms. In the second O2- site, O2- is bonded in a bent 150 degrees geometry to one Re7+ and one H1+ atom. In the third O2- site, O2- is bonded in a single-bond geometry to one Re7+ atom. In the fourth O2- site, O2- is bonded in a bent 150 degrees geometry to one Re7+ and one H1+ atom. In the fifth O2- site, O2- is bonded in a single-bond geometry to one Re7+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SrCd2H16(Br3O4)2 by Materials Project

Sr(H2O)6(CdBr3)2(H2O)2 crystallizes in the orthorhombic P2_12_12 space group. The structure is one-dimensional and consists of four water molecules; two CdBr3 ribbons oriented in the (1, 0, 0) direction; and two Sr(H2O)6 ribbons oriented in the (1, 0, 0) direction. In each CdBr3 ribbon, Cd2+ is bonded to six Br1- atoms to form edge-sharing CdBr6 octahedra. There are a spread of Cd–Br bond distances ranging from 2.75–3.01 Å. There are three inequivalent Br1- sites. In the first Br1- site, Br1- is bonded in a water-like geometry to two equivalent Cd2+ atoms. In the second Br1- site, Br1- is bonded in a single-bond geometry to one Cd2+ atom. In the third Br1- site, Br1- is bonded in a 3-coordinate geometry to three equivalent Cd2+ atoms. In each Sr(H2O)6 ribbon, Sr2+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of Sr–O bond distances ranging from 2.56–2.85 Å. There are six inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a water-like geometry to two equivalent Sr2+ and two equivalent H1+ atoms. In the second O2- site, O2- is bonded in a water-like geometry to one Sr2+ and two equivalent H1+ atoms. In the third O2- site, O2- is bonded in a water-like geometry to two equivalent Sr2+ and two H1+ atoms. In the fourth O2- site, O2- is bonded in a water-like geometry to one Sr2+ and two H1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SnH10Cl4O5 by Materials Project

SnCl4(H2O)2(H2O)3 crystallizes in the monoclinic C2/c space group. The structure is zero-dimensional and consists of twelve water molecules and four SnCl4(H2O)2 clusters. In each SnCl4(H2O)2 cluster, Sn4+ is bonded in an octahedral geometry to two equivalent O2- and four Cl1- atoms. Both Sn–O bond lengths are 2.16 Å. All Sn–Cl bond lengths are 2.43 Å. There are two inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.01 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. O2- is bonded in a distorted bent 120 degrees geometry to one Sn4+ and two H1+ atoms. There are two inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a single-bond geometry to one Sn4+ atom. In the second Cl1- site, Cl1- is bonded in a single-bond geometry to one Sn4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Al2FeP2(HO)18 by Materials Project

Fe(OH)2(AlPO4(H2O)2)2(H2O)4 crystallizes in the triclinic P-1 space group. The structure is two-dimensional and consists of one iron dihydroxide molecule; four water molecules; and one AlPO4(H2O)2 sheet oriented in the (0, 0, 1) direction. In the AlPO4(H2O)2 sheet, there are two inequivalent Al3+ sites. In the first Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with two equivalent AlO6 octahedra and corners with four equivalent PO4 tetrahedra. The corner-sharing octahedral tilt angles are 43°. There are a spread of Al–O bond distances ranging from 1.89–2.00 Å. In the second Al3+ site, Al3+ is bonded to six O2- atoms to form AlO6 octahedra that share corners with two equivalent AlO6 octahedra and corners with two equivalent PO4 tetrahedra. The corner-sharing octahedral tilt angles are 43°. There are a spread of Al–O bond distances ranging from 1.87–1.96 Å. P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with three AlO6 octahedra. The corner-sharing octahedra tilt angles range from 41–51°. There are a spread of P–O bond distances ranging from 1.52–1.64 Å. There are four inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the second H1+ site, H1+ is bonded in a distorted single-bond geometry to two O2- atoms. There is one shorter (1.01 Å) and one longer (1.67 Å) H–O bond length. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal non-coplanar geometry to one Al3+ and two H1+ atoms. In the second O2- site, O2- is bonded in a bent 120 degrees geometry to one Al3+ and one P5+ atom. In the third O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Al3+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a water-like geometry to one P5+ and one H1+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to one Al3+, one P5+, and one H1+ atom. In the sixth O2- site, O2- is bonded in a distorted trigonal planar geometry to two Al3+ and one H1+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2024

Trebiskyite, the First Titanium-Decavanadate Mineral

Abstract Trebiskyite, Na3Mg2[TiV9O28]·22H2O, from the Pickett Corral mine, Bull Canyon, Montrose County, Colorado, USA, is the first mineral containing essential Ti as a component of a decavanadate polyanion. Crystals are thin prisms or needles up to ∼0.3 mm in length, occurring as individuals and in divergent sprays. Trebiskyite crystals are translucent yellow with vitreous luster and pale-yellow streak and are non-fluorescent under both longwave and shortwave ultraviolet illumination. The crystals exhibit elongation on [001] and are modified by several 0kl prism forms, possibly corresponding to {010}, {011}, and {012}. The Mohs hardness is ca. 2 based on scratch tests. Crystals have brittle tenacity with irregular fracture. No apparent cleavage, nor twinning, was evident, and the mineral is readily soluble in H2O. The density measured by flotation in methylene iodide-toluene mixture is 2.38(2) g/cm3. The calculated density is 2.352 g/cm3 for the empirical formula and 2.343 g/cm3 for the ideal formula. Electron microprobe analyses provided the empirical formula Na3.39Mg1.87V8.75Ti1.25O50H44.00, based on Ti + V = 10 apfu, O = 50 apfu, with the Na content having been determined from the refined crystal structure. Trebiskyite is monoclinic, space group P21/c, a = 9.478(4), b = 21.426(11), c = 11.267(5) Å, β = 114.572(7)°, V = 2080.8(13) Å3, Z = 2. The structure was refined from 6642 reflections to a final R1 = 0.0517 for reflections I > 2σ(I). The structural unit of trebiskyite, (TiV9O28)7−, is built from a Ti-substituted decavanadate polyanion, (V10O28)6−, found in other members of the pascoite family. Chemically, trebiskyite is closely related to lasalite, Na2Mg2[V10O28]·20H2O, and huemulite, Na4Mg[V10O28]·24H2O; however, trebiskyite contains a novel structural arrangement that is unique among the decavanadate minerals. The interstitial complex in trebiskyite has the ideal formula {[Na3Mg2(H2O)19](H2O)3} and consists of chains of distorted octahedrally coordinated Na+ and regular Mg[O(H2O)5] octahedra. The observed low incident bond valence to the V1 site (4.45 vu) and marked deviation in vanadyl and V–Oeq bond lengths indicate that this site is host to the essential Ti4+ identified during chemical analyses.

Mineralogy↗
NASA NTRS1972

The photolysis of ozone

Ozone was photolyzed at 25 C with steady illumination at several wavelengths from 2288 to 2850 A, at O3 pressures from 0.1 to 2.7 torr, and at absorbed intensities from 0.15 to 65 microns/min. Experiments were done in pure dry O3, and in the presence of He, CO2, N2, H2O, H2, N2O, He-CO2, He-H2O, CO2-H2O, O2-N2O, CO2-O2, and N2O5-O2-CO2 mixtures. The results show that in the absence of added gases or in the presence of He, the quantum yield of O3 consumption is 5.5 independent of conditions, except at pressures below 0.4 torr. In the presence of CO2 or N2, ozone consumption falls toward 4.0. The primary photolytic act produces O(1 D) and siglet O2, presumably O2(1 delta), at all wavelengths below 3000 A. Relative quenching constants O(1 D) removal by various gases were measured at 2288, 2537, and 2800 A. For O3, CO2, and N2, the relative rates are 1.0/0.4 to 0.5/0.08 to 0.11 at all wavelengths. For H2O the constant at 2537 A is 1.5 relative to that for O3. With N2O, a noticeable wavelength effect is observed and the relative rate constants are 1.5, 2 to 3, 4.0 for O3 compared to N2O at 2800, 2537, and 2288 A, respectively.

Lissi, E.↗
NASA NTRS1977

Interaction of NaCl(g) and HCl(g) with condensed NA2SO4

The interaction of Na2SO4(l) with NaCl(g), HCl(g) and H2O(g) was studied in atmospheric pressure flowing air and oxygen at Na2SO4(l) temperatures of 900 and 1000 C. Thermomicrogravimetric and high pressure mass spectrometric sampling techniques were used. Experimental results establish that previously reported enhanced rates of weight loss of Na2SO4(l) in the presence of NaCl(g) are due to the reaction: Na2SO4(c) + 2HCl(g) = 2NaCl(g) + SO2(g) + H2O(g) + 1/2O2(g) being driven to the right in flowing gas systems. The HCl(g) is the product of hydrolysis of NaCl caused by small but significant amounts of H2O(g) present in the system. Thermochemical calculations are used to show that even with sub-ppm levels of H2O(g) present, significant quantities of HCl(g) are produced.

Stearns, C. A.↗
NASA NTRS1980

Production of OH from photolysis of HOCl at 307-309 nm

Laser-induced fluorescence has been used to measure the amount of OH produced in the laser photolysis of HOCl at 310 nm. The HOCl was generated by the Cl2O + H2O and by the HCl + Cl2O reactions. The laser technique samples OH on a microsecond time scale so that secondary radical reactions cannot contribute significantly to the observed signals. The fluorescence signals were calibrated with O3-H2O mixtures, the reactions O3 + h(nu) yields O(1D) + O2 and O(1D) + H2O yields 2OH yielding known amounts of OH. The value for the absorption cross section of HOCl at 310 nm has been determined to be 6 x 10 to the -20th sq cm, assuming K(eq) = 0.082 for the Cl2O + H2O yields 2HOCl system and assuming unit quantum yield for the production of OH. The present investigation further supports earlier experimental work concluding that HOCl will photodissociate rapidly and will not be an important holding tank for chlorine in the stratosphere. These results are in disagreement with theoretical calculations of the UV absorption spectrum of HOCl in the 300-350-nm wavelength region.

Molina, M. J.↗
NASA NTRS1982

Aspects of the history of 66095 based on trace elements in clasts and whole rock

Halogens, P, U and Na are reported in anorthositic and basaltic clasts and matrix from rusty rock 66095. Large fractions of Cl and Br associated with the separated phases from 66095 are soluble in H2O. Up to two orders of magnitude variation in concentrations of these elements in the breccia components and varying H2O-soluble Cl/Br ratios indicate different sources of volatiles. An approximately constant ratio of the H2O- to 0.1 M HNO3-soluble Br in the various components suggests no appreciable alteration in the original distributions of this element in the breccia forming processes. Up to 50% or more of the phosphorus and of the non-H2O-soluble Cl was dissolved from most of the breccia components by 0.1 M HNO3. Clast and matrix residues from the leaching steps contain, in most cases, the Cl/P2O5 ratio found in 66095 whole rock and in a number of other Apollo 16 samples. Evidence that phosphates are the major P-phases in the breccia is based on the 0.1 M acid solubility of Cl and P in the matrix sample and on elemental concentrations which are consistent with those of KREEP.

Jovanovic, S.↗
NASA NTRS1984

Development and preliminary tests of a new long-wave radiation parameterization

An efficient broad band longwave radiation code for CO2 and H2O and for O3 was developed. There are two bands each in the CO2 and H2O absorption regions, one for the band center and one for the band wings. One band covers O3 absorption and the overlapping H2O continuum. Overlap is also considered in the CO2 region, and there is H2O continuum absorption where applicable. Clouds are considered nonreflecting in the longwave. Therefore partial cover or partial transmission can be allowed for, by considering a cloud fraction at each atmospheric level. A special subroutine was written to allow for maximum or random overlap of clouds that may be used in the future. All algorithms were written with vectorization in mind with identical operations made for all horizontal grid points in a latitude circle. Where possible, operations are carried out covering the vertical grid points as well, yielding long vectors for efficient computations.

HARSHVARDHAN↗
NASA NTRS1984

Workshop on Water on Mars

The opening session of the Workshop focused on one of the most debated areas of Mars volatiles research-the size of the planet's past and present bulk water content. Current estimates of the inventory of H2O on Mars range from an equivalent layer of liquid 10-1000 meters deep averaged over the planet's surface. The most recent of these estimates, presented at the Workshop, is based on the now popular belief that the SNC class of meteorites represent actual samples of the Martian crust. From a model of planetary accretion and degassing founded on this assumption, it was determined that the present inventory of H2O on Mars is equivalent to a global layer no more than 50 meters deep. During the discussion generated by this estimate, several investigators expressed reservations about an H2O inventory as small as a few tens of meters, for it appears to directly contradict the seemingly abundant morphologic evidence that Mars is (or has been) water rich. Others, however, argued that the interpretation of much of this morphologic evidence is at best equivocal and that the case for a wet Mars is far from established. Atmospheric water vapor measurements, compiled by Earth based telescopes and the Viking Orbiter Mars Atmospheric Water Detectors (MAWD), now span a period of over six Martian years. Analysis of this data suggests that the seasonal cycle is governed by both the sublimation and condensation of H2O at the poles and by its adsorption/desorption within the regolith. So far, efforts to simulate the seasonal vapor cycle have failed to reproduce the observed behavior.

Clifford, S.↗
NASA NTRS1986

Interstellar grain mantles

Interstellar molecular grain mantles are an important component of the interstellar dust inside dense molecular clouds as evidenced by the detection of absorption bands at 2.97, 3.08, 4.61, 6.0 and 6.8 microns. Mantles may also be the precursors of more complex grain mantles in the diffuse interstellar medium. The molecular composition of these icy grain mantles were calculated employing gas phase as well as grain surface reactions. The calculated mixtures consist mainly of the molecules H2O, H2CO, N2, CO, O2, H2O2, NH2, and their deuterated counterparts in varying ratios. The exact compositions depend strongly on the physical conditions in the gas phase. The absorption spectra of H2O with other molecules was studied in the laboratory. Optical constants were determined for a few selected mixtures. Extinction and polarization cross sections across the 3 micron ice band were calculated. A comparison with the observations towards BN shows that the low frequency wing observed on this feature is due to absorption by a mixture of H2O and other molecules rather than scattering by large, pure H2O ice grains.

Bregman, J.↗
NASA NTRS1986

Water vapor in Jupiter's atmosphere

High spectral resolution observations of Jupiter at 2.7 and 5 microns acquired from the Kuiper Airborne Observatory were used to infer the vertical distribution of H2O between 0.7 and 6 bars. The H2O mole fraction, qH2O, is saturated for P<2 bars, qH2O = 4x.000001 in the 2 to 4 bar range and it increases to 3x.00001 at 6 bars where T = 288 K. The base of the 5 micron line formation region is determined by pressure-induced H2 opacity. At this deepest accessible level, the O/H ratio in Jupiter is depleted by a factor of 50 with respect to the solar atmosphere. High spatial resolution Voyager IRIS spectra of Jupiter's North Tropical Zone, Equatorial Zone, and Hot Spots in the North and South Equatorial Belt were analyzed to determine the spatial variation of H2O across the planet. The column abundance of H2O above the 4 bar level is the same in the zones as in the SEB Hot Spots, about 20 cm-amgt. A cloud model for Jupiter's belts and zones was developed in order to fit the IRIS 5 micron spectra. An absorbing cloud located at 2 bars whose 5 micron optical thickness varies between 1 in the Hot Spots and 4 in the coldest zones satisfactorily matches the IRIS data.

Bjoraker, G. L.↗
NASA NTRS1986

Velocity-resolved observations of water in Comet Halley

High resolution (lambda/delta lambda approx. = 3 x 10 to the 5th power) near-infrared observations of H2O emission from Comet Halley were acquired at the time of maximum post-perihelion geocentric Doppler shift. The observed widths and absolute positions of the H2O line profiles reveal characteristics of the molecular velocity field in the coma. These results support H2O outflow from a Sun-lit hemisphere or the entire nucleus, but not from a single, narrow jet emanating from the nucleus. The measured pre- and post-perihelion outflow velocities were 0.9 + or - 0.2 and 1.4 + or - 0.2 km/s, respectively. Temporal variations in the kinematic properties of the outflow were inferred from changes in the spectral line shapes. These results are consistent with the release of H2O into the coma from multiple jets.

Larson, Harold P.↗