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At least 181 records · Page 10
All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Materials Data on K8Rb2Hg15(GeS4)10 by Materials Project

Rb2K8Hg15(GeS4)10 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are two inequivalent Rb1+ sites. In the first Rb1+ site, Rb1+ is bonded in a 7-coordinate geometry to eight S2- atoms. There are a spread of Rb–S bond distances ranging from 3.30–3.92 Å. In the second Rb1+ site, Rb1+ is bonded in a 7-coordinate geometry to eight S2- atoms. There are a spread of Rb–S bond distances ranging from 3.29–3.92 Å. There are eight inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of K–S bond distances ranging from 3.28–3.53 Å. In the second K1+ site, K1+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of K–S bond distances ranging from 3.28–3.53 Å. In the third K1+ site, K1+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of K–S bond distances ranging from 3.28–3.53 Å. In the fourth K1+ site, K1+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of K–S bond distances ranging from 3.28–3.53 Å. In the fifth K1+ site, K1+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of K–S bond distances ranging from 3.28–3.53 Å. In the sixth K1+ site, K1+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of K–S bond distances ranging from 3.28–3.53 Å. In the seventh K1+ site, K1+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of K–S bond distances ranging from 3.27–3.53 Å. In the eighth K1+ site, K1+ is bonded in a 7-coordinate geometry to seven S2- atoms. There are a spread of K–S bond distances ranging from 3.28–3.53 Å. There are fifteen inequivalent Hg2+ sites. In the first Hg2+ site, Hg2+ is bonded in a see-saw-like geometry to four S2- atoms. There are two shorter (2.47 Å) and two longer (2.92 Å) Hg–S bond lengths. In the second Hg2+ site, Hg2+ is bonded in a see-saw-like geometry to four S2- atoms. There are two shorter (2.47 Å) and two longer (2.92 Å) Hg–S bond lengths. In the third Hg2+ site, Hg2+ is bonded in a see-saw-like geometry to four S2- atoms. There are two shorter (2.47 Å) and two longer (2.92 Å) Hg–S bond lengths. In the fourth Hg2+ site, Hg2+ is bonded in a see-saw-like geometry to four S2- atoms. There are two shorter (2.47 Å) and two longer (2.92 Å) Hg–S bond lengths. In the fifth Hg2+ site, Hg2+ is bonded in a see-saw-like geometry to four S2- atoms. There are two shorter (2.47 Å) and two longer (2.92 Å) Hg–S bond lengths. In the sixth Hg2+ site, Hg2+ is bonded in a see-saw-like geometry to four S2- atoms. There are two shorter (2.49 Å) and two longer (2.87 Å) Hg–S bond lengths. In the seventh Hg2+ site, Hg2+ is bonded in a see-saw-like geometry to four S2- atoms. There are a spread of Hg–S bond distances ranging from 2.49–2.87 Å. In the eighth Hg2+ site, Hg2+ is bonded in a see-saw-like geometry to four S2- atoms. There are a spread of Hg–S bond distances ranging from 2.49–2.87 Å. In the ninth Hg2+ site, Hg2+ is bonded in a see-saw-like geometry to four S2- atoms. There are two shorter (2.49 Å) and two longer (2.87 Å) Hg–S bond lengths. In the tenth Hg2+ site, Hg2+ is bonded in a see-saw-like geometry to four S2- atoms. There are two shorter (2.49 Å) and two longer (2.87 Å) Hg–S bond lengths. In the eleventh Hg2+ site, Hg2+ is bonded in a distorted linear geometry to four S2- atoms. There are a spread of Hg–S bond distances ranging from 2.38–3.31 Å. In the twelfth Hg2+ site, Hg2+ is bonded in a distorted linear geometry to four S2- atoms. There are a spread of Hg–S bond distances ranging from 2.38–3.31 Å. In the thirteenth Hg2+ site, Hg2+ is bonded in a distorted linear geometry to four S2- atoms. There are a spread of Hg–S bond distances ranging from 2.38–3.31 Å. In the fourteenth Hg2+ site, Hg2+ is bonded in a distorted linear geometry to four S2- atoms. There are two shorter (2.38 Å) and two longer (3.30 Å) Hg–S bond lengths. In the fifteenth Hg2+ site, Hg2+ is bonded in a distorted linear geometry to four S2- atoms. There are two shorter (2.38 Å) and two longer (3.30 Å) Hg–S bond lengths. There are eight inequivalent Ge4+ sites. In the first Ge4+ site, Ge4+ is bonded in a tetrahedral geometry to four S2- atoms. There are a spread of Ge–S bond distances ranging from 2.20–2.29 Å. In the second Ge4+ site, Ge4+ is bonded in a tetrahedral geometry to four S2- atoms. There are a spread of Ge–S bond distances ranging from 2.19–2.28 Å. In the third Ge4+ site, Ge4+ is bonded in a tetrahedral geometry to four S2- atoms. There are a spread of Ge–S bond distances ranging from 2.19–2.28 Å. In the fourth Ge4+ site, Ge4+ is bonded in a tetrahedral geometry to four S2- atoms. There are a spread of Ge–S bond distances ranging from 2.20–2.29 Å. In the fifth Ge4+ site, Ge4+ is bonded in a tetrahedral geometry to four S2- atoms. There are a spread of Ge–S bond distances ranging from 2.20–2.29 Å. In the sixth Ge4+ site, Ge4+ is bonded in a tetrahedral geometry to four S2- atoms. There are a spread of Ge–S bond distances ranging from 2.20–2.29 Å. In the seventh Ge4+ site, Ge4+ is bonded in a tetrahedral geometry to four S2- atoms. There are a spread of Ge–S bond distances ranging from 2.20–2.29 Å. In the eighth Ge4+ site, Ge4+ is bonded in a tetrahedral geometry to four S2- atoms. There are a spread of Ge–S bond distances ranging from 2.19–2.29 Å. There are thirty inequivalent S2- sites. In the first S2- site, S2- is bonded in a 5-coordinate geometry to two equivalent K1+, two Hg2+, and one Ge4+ atom. In the second S2- site, S2- is bonded in a 5-coordinate geometry to two equivalent K1+, two Hg2+, and one Ge4+ atom. In the third S2- site, S2- is bonded in a 5-coordinate geometry to two equivalent K1+, two Hg2+, and one Ge4+ atom. In the fourth S2- site, S2- is bonded in a 5-coordinate geometry to two equivalent K1+, two Hg2+, and one Ge4+ atom. In the fifth S2- site, S2- is bonded in a 5-coordinate geometry to one Rb1+, one K1+, two Hg2+, and one Ge4+ atom. In the sixth S2- site, S2- is bonded in a 5-coordinate geometry to two Rb1+, two Hg2+, and one Ge4+ atom. In the seventh S2- site, S2- is bonded in a 5-coordinate geometry to one Rb1+, one K1+, two Hg2+, and one Ge4+ atom. In the eighth S2- site, S2- is bonded in a 5-coordinate geometry to two K1+, two Hg2+, and one Ge4+ atom. The S–Ge bond length is 2.26 Å. In the ninth S2- site, S2- is bonded in a 4-coordinate geometry to one K1+, two Hg2+, and one Ge4+ atom. In the tenth S2- site, S2- is bonded in a 4-coordinate geometry to one Rb1+, two Hg2+, and one Ge4+ atom. In the eleventh S2- site, S2- is bonded in a 4-coordinate geometry to one Rb1+, two Hg2+, and one Ge4+ atom. In the twelfth S2- site, S2- is bonded in a 4-coordinate geometry to one K1+, two Hg2+, and one Ge4+ atom. In the thirteenth S2- site, S2- is bonded in a 1-coordinate geometry to one Rb1+, one K1+, two Hg2+, and one Ge4+ atom. In the fourteenth S2- site, S2- is bonded in a 1-coordinate geometry to one Rb1+, one K1+, two Hg2+, and one Ge4+ atom. In the fifteenth S2- site, S2- is bonded in a 4-coordinate geometry to one K1+, two Hg2+, and one Ge4+ atom. In the sixteenth S2- site, S2- is bonded in a 2-coordinate geometry to two K1+, one Hg2+, and one Ge4+ atom. In the seventeenth S2- site, S2- is bonded in a 2-coordinate geometry to two K1+, one Hg2+, and one Ge4+ atom. In the eighteenth S2- site, S2- is bonded in a 2-coordinate geometry to two K1+, one Hg2+, and one Ge4+ atom. In the nineteenth S2- site, S2- is bonded in a 2-coordinate geometry to two K1+, one Hg2+, and one Ge4+ atom. In the twentieth S2- site, S2- is bonded in a 2-coordinate geometry to two equivalent K1+, one Hg2+, and one Ge4+ atom. In the twenty-first S2- site, S2- is bonded in a 2-coordinate geometry to two equivalent Rb1+, one Hg2+, and one Ge4+ atom. In the twenty-second S2- site, S2- is bonded in a 2-coordinate geometry to two equivalent Rb1+, one Hg2+, and one Ge4+ atom. In the twenty-third S2- site, S2- is bonded in a 4-coordinate geometry to two K1+, one Hg2+, and one Ge4+ atom. In the twenty-fourth S2- site, S2- is bonded in a 4-coordinate geometry to one Rb1+, one K1+, one Hg2+, and one Ge4+ atom. In the twenty-fifth S2- site, S2- is bonded in a 4-coordinate geometry to one Rb1+, one K1+, one Hg2+, and one Ge4+ atom. In the twenty-sixth S2- site, S2- is bonded in a 4-coordinate geometry to two K1+, one Hg2+, and one Ge4+ atom. In the twenty-seventh S2- site, S2- is bonded in a 4-coordinate geometry to one Rb1+, one K1+, one Hg2+, and one Ge4+ atom. In the twenty-eighth S2- site, S2- is bonded in a 4-coordinate geometry to one Rb1+, one K1+, one Hg2+, and one Ge4+ atom. In the twenty-ninth S2- site, S2- is bonded in a 4-coordinate geometry to two K1+, one Hg2+, and one Ge4+ atom. In the thirtieth S2- site, S2- is bonded in a 4-coordinate geometry to two K1+, one Hg2+, and one Ge4+ atom. The S–Ge bond length is 2.29 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on U2Hg5(AsO9)2 by Materials Project

U2Hg5(AsO9)2 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. U is bonded to seven O atoms to form distorted UO7 pentagonal bipyramids that share corners with three equivalent AsO4 tetrahedra and an edgeedge with one UO7 pentagonal bipyramid. There are a spread of U–O bond distances ranging from 1.83–2.40 Å. There are three inequivalent Hg sites. In the first Hg site, Hg is bonded in a linear geometry to two equivalent O atoms. Both Hg–O bond lengths are 2.00 Å. In the second Hg site, Hg is bonded in a distorted linear geometry to two O atoms. There are one shorter (2.04 Å) and one longer (2.05 Å) Hg–O bond lengths. In the third Hg site, Hg is bonded in a 4-coordinate geometry to four O atoms. There are a spread of Hg–O bond distances ranging from 2.10–2.66 Å. As is bonded to four O atoms to form AsO4 tetrahedra that share corners with three equivalent UO7 pentagonal bipyramids. There are a spread of As–O bond distances ranging from 1.71–1.76 Å. There are nine inequivalent O sites. In the first O site, O is bonded in a bent 150 degrees geometry to one U and one As atom. In the second O site, O is bonded in a distorted bent 150 degrees geometry to one U and one As atom. In the third O site, O is bonded in a 1-coordinate geometry to one U, one Hg, and one As atom. In the fourth O site, O is bonded in a bent 120 degrees geometry to one Hg and one As atom. In the fifth O site, O is bonded in a 2-coordinate geometry to two Hg atoms. In the sixth O site, O is bonded in a bent 120 degrees geometry to two Hg atoms. In the seventh O site, O is bonded in a trigonal planar geometry to two equivalent U and one Hg atom. In the eighth O site, O is bonded in a single-bond geometry to one U atom. In the ninth O site, O is bonded in a single-bond geometry to one U atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on InHg7S6Cl5 by Materials Project

Hg7InS6Cl5 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are eight inequivalent Hg2+ sites. In the first Hg2+ site, Hg2+ is bonded in a 2-coordinate geometry to two equivalent S2- and four Cl1- atoms. Both Hg–S bond lengths are 2.41 Å. There are two shorter (3.34 Å) and two longer (3.44 Å) Hg–Cl bond lengths. In the second Hg2+ site, Hg2+ is bonded to two S2- and four Cl1- atoms to form distorted HgS2Cl4 octahedra that share corners with two equivalent HgS3Cl3 octahedra and edges with two equivalent InS2Cl4 octahedra. The corner-sharing octahedra tilt angles range from 57–71°. There are one shorter (2.41 Å) and one longer (2.42 Å) Hg–S bond lengths. There are a spread of Hg–Cl bond distances ranging from 3.13–3.36 Å. In the third Hg2+ site, Hg2+ is bonded to three S2- and three Cl1- atoms to form distorted HgS3Cl3 octahedra that share corners with two equivalent HgS2Cl4 octahedra and corners with two equivalent InS2Cl4 octahedra. The corner-sharing octahedra tilt angles range from 34–71°. There are a spread of Hg–S bond distances ranging from 2.40–3.23 Å. There are a spread of Hg–Cl bond distances ranging from 3.00–3.35 Å. In the fourth Hg2+ site, Hg2+ is bonded in a 4-coordinate geometry to two S2- and two equivalent Cl1- atoms. Both Hg–S bond lengths are 2.41 Å. There are one shorter (3.19 Å) and one longer (3.28 Å) Hg–Cl bond lengths. In the fifth Hg2+ site, Hg2+ is bonded in a 5-coordinate geometry to three S2- and two Cl1- atoms. There are a spread of Hg–S bond distances ranging from 2.47–2.62 Å. There are one shorter (3.30 Å) and one longer (3.39 Å) Hg–Cl bond lengths. In the sixth Hg2+ site, Hg2+ is bonded in a 4-coordinate geometry to three S2- and one Cl1- atom. There are a spread of Hg–S bond distances ranging from 2.42–3.30 Å. The Hg–Cl bond length is 2.84 Å. In the seventh Hg2+ site, Hg2+ is bonded in a 5-coordinate geometry to three S2- and two Cl1- atoms. There are a spread of Hg–S bond distances ranging from 2.43–2.77 Å. There are one shorter (3.18 Å) and one longer (3.45 Å) Hg–Cl bond lengths. In the eighth Hg2+ site, Hg2+ is bonded in a distorted linear geometry to two equivalent S2- atoms. Both Hg–S bond lengths are 2.40 Å. In3+ is bonded to two S2- and four Cl1- atoms to form InS2Cl4 octahedra that share corners with two equivalent HgS3Cl3 octahedra and edges with two equivalent HgS2Cl4 octahedra. The corner-sharing octahedra tilt angles range from 34–40°. There are one shorter (2.66 Å) and one longer (2.76 Å) In–S bond lengths. There are a spread of In–Cl bond distances ranging from 2.51–2.57 Å. There are six inequivalent S2- sites. In the first S2- site, S2- is bonded in a 4-coordinate geometry to four Hg2+ atoms. In the second S2- site, S2- is bonded in a 3-coordinate geometry to three Hg2+ atoms. In the third S2- site, S2- is bonded in a 3-coordinate geometry to three Hg2+ atoms. In the fourth S2- site, S2- is bonded in a 3-coordinate geometry to four Hg2+ atoms. In the fifth S2- site, S2- is bonded in a distorted trigonal non-coplanar geometry to two Hg2+ and one In3+ atom. In the sixth S2- site, S2- is bonded in a 3-coordinate geometry to two Hg2+ and one In3+ atom. There are five inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a 1-coordinate geometry to three Hg2+ and one In3+ atom. In the second Cl1- site, Cl1- is bonded in a 1-coordinate geometry to four Hg2+ and one In3+ atom. In the third Cl1- site, Cl1- is bonded in a 1-coordinate geometry to two Hg2+ and one In3+ atom. In the fourth Cl1- site, Cl1- is bonded in a 2-coordinate geometry to four Hg2+ atoms. In the fifth Cl1- site, Cl1- is bonded in a 1-coordinate geometry to three Hg2+ and one In3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2021

Evaluation of engineered sorbents for the sorption of mercury from contaminated bank soils: a column study

Abstract As a global environmental pollutant, mercury (Hg) threatens our water resources and presents a substantial risk to human health. The rate and extent of immobilization of Hg 2+ (hereafter, Hg) on engineered sorbents (Thiol-SAMMS®, pine biochar, SediMite™, Organoclay™ PM-199, and quartz sand as a control) was evaluated using flow-through column experiments. The effectiveness of the sorbents was based on (1) the percentage of Hg removed in relation to the total amount of Hg passing the sorbent column, and (2) the rate of Hg uptake compared to the nonreactive tracer bromide (Br − ). All sorbents removed Hg to a certain extent, but none of the sorbents removed all the Hg introduced to the columns. Thiol-SAMMS showed the highest mean percentage of Hg removed (87% ± 2.9%), followed by Organoclay PM-199 (71% ± 0.4%), pine biochar (57% ± 22.3%), SediMite (61% ± 0.8%), and the control quartz sand (11% ± 5.6%). Thiol-SAMMS was the only sorbent to exhibit retardation of Hg in comparison to the conservative tracer Br − . For the remaining sorbents, Br − along with low concentrations of Hg were eluted within the first 3 pore volumes, indicating limited retardation of Hg. Overall, removal of Hg by sorbents was substantial, suggesting that sorbents might be suitable for deployment in contaminated environments. High concentrations of DOM leaching from the soil columns likely influenced the speciation of Hg and inhibited sorption to the sorbents. Incomplete removal of Hg by any sorbent suggests that additional optimization is needed to increase efficiency.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2025

Evaluation of Technologies to Mitigate the Presence of Gaseous Elemental Mercury in Waste Disposal Containers

A study was conducted to evaluate sorbent technologies that can mitigate the presence of elemental mercury (Hg⁰) in waste containers for mercury-contaminated debris (MCD). Decontamination and demolition (D&D) activities at the Y-12 National Security Complex (Y-12) and other U.S. Department of Energy (DOE) Oak Ridge Reservation (ORR) facilities generate MCD requiring offsite disposal. The debris is packaged in appropriate waste containers and may be temporarily stored onsite prior to transport for treatment and/or disposal. During transportation of loads that had no visible liquid Hg at the point of origin, temperature changes can cause Hg⁰ to evaporate, condense, and form droplets on container walls. Furthermore, vibration during transportation could cause beads of Hg to be released from the debris, container walls, and ceiling, resulting in pools of liquid Hg⁰ on the container floor. Waste acceptance criteria (WAC) limitations for commercial disposal facilities, the Nevada National Security Site (NNSS), and ORR mixed low-level waste landfills prohibit the presence of any free liquids in containers identified as a solid waste form. Potential solutions to mitigate the presence of residual liquids that could be formed through vapor condensation include the use of sorbents or similar materials to capture and stabilize volatile Hg⁰ vapors and thus ensure compliance with landfill WAC requirements. This report summarizes data from small-scale laboratory experiments conducted to evaluate sorbent materials for Hg⁰ vapor suppression and sorption of liquid Hg⁰ that could form under relevant transportation and disposal conditions. A series of experiments was conducted to evaluate commercial sorbent materials and their effectiveness for Hg⁰ sorption across a temperature range from 19.4°C to 60°C. The impact of residual moisture on sorption was investigated under relevant conditions, and leaching tests were performed to assess the stability of Hg⁰ captured sorbent materials. The results provide estimates for sorbent quantities needed for a given Hg⁰ mass loading based on experimental results exposing sorbents to gaseous and liquid Hg⁰ at various mass ratios. Overall, sorbents that were most effective for Hg⁰ vapor suppression were brominated activated carbons, mackinawite-based sorbents coated on vermiculite, and sulfur-modified granular activated carbon. Elevated temperatures and moisture conditions did not result in significant increases of Hg⁰ headspace concentrations, and the materials also demonstrated high sorption capacities for the sorption of liquid Hg⁰.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2021

Mercury-Tolerant Ensifer medicae Strains Display High Mercuric Reductase Activity and a Protective Effect on Nitrogen Fixation in Medicago truncatula Nodules Under Mercury Stress

Mercury (Hg) is extremely toxic for all living organisms. Hg-tolerant symbiotic rhizobia have the potential to increase legume tolerance, and to our knowledge, the mechanisms underlying Hg tolerance in rhizobia have not been investigated to date. Rhizobial strains of Ensifer medicae, Rhizobium leguminosarum bv. trifolii and Bradyrhizobium canariense previously isolated from severely Hg-contaminated soils showed different levels of Hg tolerance. The ability of the strains to reduce mercury Hg 2+ to Hg o , a volatile and less toxic form of mercury, was assessed using a Hg volatilization assay. In general, tolerant strains displayed high mercuric reductase activity, which appeared to be inducible in some strains when grown at a sub-lethal HgCl 2 concentration. A strong correlation between Hg tolerance and mercuric reductase activity was observed for E. medicae strains, whereas this was not the case for the B. canariense strains, suggesting that additional Hg tolerance mechanisms could be playing a role in B. canariense. Transcript abundance from merA, the gene that encodes mercuric reductase, was quantified in tolerant and sensitive E. medicae and R. leguminosarum strains. Tolerant strains presented higher merA expression than sensitive ones, and an increase in transcript abundance was observed for some strains when bacteria were grown in the presence of a sub-lethal HgCl 2 concentration. These results suggest a regulation of mercuric reductase in rhizobia. Expression of merA genes and mercuric reductase activity were confirmed in Medicago truncatula nodules formed by a sensitive or a tolerant E. medicae strain. Transcript accumulation in nodules formed by the tolerant strain increased when Hg stress was applied, while a significant decrease in expression occurred upon stress application in nodules formed by the Hg-sensitive strain. The effect of Hg stress on nitrogen fixation was evaluated, and in our experimental conditions, nitrogenase activity was not affected in nodules formed by the tolerant strain, while a significant decrease in activity was observed in nodules elicited by the Hg-sensitive bacteria. Our results suggest that the combination of tolerant legumes with tolerant rhizobia constitutes a potentially powerful tool in the bioremediation of Hg-contaminated soils.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2020

Materials Data on Ba(TlHg)2 by Materials Project

Ba(HgTl)2 crystallizes in the tetragonal P4_2/mnm space group. The structure is three-dimensional. Ba is bonded in a 12-coordinate geometry to nine Hg and six equivalent Tl atoms. There are a spread of Ba–Hg bond distances ranging from 3.67–4.03 Å. There are four shorter (3.74 Å) and two longer (4.23 Å) Ba–Tl bond lengths. There are two inequivalent Hg sites. In the first Hg site, Hg is bonded in a 2-coordinate geometry to five equivalent Ba, three Hg, and two equivalent Tl atoms. There are two shorter (2.98 Å) and one longer (2.99 Å) Hg–Hg bond lengths. Both Hg–Tl bond lengths are 3.24 Å. In the second Hg site, Hg is bonded in a 8-coordinate geometry to four equivalent Ba, two equivalent Hg, and two equivalent Tl atoms. Both Hg–Tl bond lengths are 3.18 Å. Tl is bonded in a 2-coordinate geometry to three equivalent Ba, two Hg, and five equivalent Tl atoms. There are one shorter (3.19 Å) and four longer (3.45 Å) Tl–Tl bond lengths.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Hg3S2ICl by Materials Project

Hg3S2ICl crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. there are five inequivalent Hg2+ sites. In the first Hg2+ site, Hg2+ is bonded in a 6-coordinate geometry to two equivalent S2-, two equivalent I1-, and two equivalent Cl1- atoms. Both Hg–S bond lengths are 2.46 Å. Both Hg–I bond lengths are 3.61 Å. Both Hg–Cl bond lengths are 3.02 Å. In the second Hg2+ site, Hg2+ is bonded to two equivalent S2-, three I1-, and one Cl1- atom to form distorted HgS2I3Cl octahedra that share corners with four equivalent HgS2I2Cl2 octahedra and an edgeedge with one HgS2I3Cl octahedra. The corner-sharing octahedral tilt angles are 61°. Both Hg–S bond lengths are 2.45 Å. There are one shorter (3.24 Å) and two longer (3.62 Å) Hg–I bond lengths. The Hg–Cl bond length is 3.20 Å. In the third Hg2+ site, Hg2+ is bonded to two equivalent S2-, two equivalent I1-, and two equivalent Cl1- atoms to form distorted HgS2I2Cl2 octahedra that share corners with four equivalent HgS2I3Cl octahedra and edges with two equivalent HgS2I2Cl2 octahedra. The corner-sharing octahedral tilt angles are 61°. Both Hg–S bond lengths are 2.43 Å. Both Hg–I bond lengths are 3.34 Å. Both Hg–Cl bond lengths are 3.46 Å. In the fourth Hg2+ site, Hg2+ is bonded in a 4-coordinate geometry to two equivalent S2- and two equivalent I1- atoms. Both Hg–S bond lengths are 2.47 Å. There are one shorter (3.08 Å) and one longer (3.25 Å) Hg–I bond lengths. In the fifth Hg2+ site, Hg2+ is bonded in a 5-coordinate geometry to two S2-, one I1-, and two Cl1- atoms. Both Hg–S bond lengths are 2.48 Å. The Hg–I bond length is 3.36 Å. There are one shorter (2.74 Å) and one longer (3.39 Å) Hg–Cl bond lengths. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a 3-coordinate geometry to three Hg2+ atoms. In the second S2- site, S2- is bonded in a 3-coordinate geometry to three Hg2+ and one I1- atom. The S–I bond length is 4.00 Å. There are two inequivalent I1- sites. In the first I1- site, I1- is bonded in a 7-coordinate geometry to five Hg2+ and two equivalent S2- atoms. In the second I1- site, I1- is bonded in a 6-coordinate geometry to six Hg2+ atoms. There are two inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a distorted trigonal planar geometry to three Hg2+ atoms. In the second Cl1- site, Cl1- is bonded in a 6-coordinate geometry to six Hg2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Hg2SbF6 by Materials Project

Hg2SbF6 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are two inequivalent Hg+1.50+ sites. In the first Hg+1.50+ site, Hg+1.50+ is bonded in a distorted rectangular see-saw-like geometry to four F1- atoms. There are two shorter (2.89 Å) and two longer (2.95 Å) Hg–F bond lengths. In the second Hg+1.50+ site, Hg+1.50+ is bonded in a 4-coordinate geometry to four F1- atoms. There are two shorter (2.86 Å) and two longer (2.94 Å) Hg–F bond lengths. Sb3+ is bonded in an octahedral geometry to six F1- atoms. All Sb–F bond lengths are 1.92 Å. There are six inequivalent F1- sites. In the first F1- site, F1- is bonded in a distorted single-bond geometry to two equivalent Hg+1.50+ and one Sb3+ atom. In the second F1- site, F1- is bonded in a distorted single-bond geometry to two Hg+1.50+ and one Sb3+ atom. In the third F1- site, F1- is bonded in a single-bond geometry to one Sb3+ atom. In the fourth F1- site, F1- is bonded in a distorted single-bond geometry to two equivalent Hg+1.50+ and one Sb3+ atom. In the fifth F1- site, F1- is bonded in a distorted single-bond geometry to two equivalent Hg+1.50+ and one Sb3+ atom. Both F–Hg bond lengths are 2.94 Å. The F–Sb bond length is 1.92 Å. In the sixth F1- site, F1- is bonded in a distorted single-bond geometry to two equivalent Hg+1.50+ and one Sb3+ atom. Both F–Hg bond lengths are 2.89 Å. The F–Sb bond length is 1.92 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CdHg6(Sb2I3)2 by Materials Project

Hg6Cd(Sb2I3)2 crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. there are seven inequivalent Hg2+ sites. In the first Hg2+ site, Hg2+ is bonded in a 6-coordinate geometry to two Sb2- and four I1- atoms. There are one shorter (2.77 Å) and one longer (2.79 Å) Hg–Sb bond lengths. There are a spread of Hg–I bond distances ranging from 3.17–3.88 Å. In the second Hg2+ site, Hg2+ is bonded in a 5-coordinate geometry to two Sb2- and three I1- atoms. Both Hg–Sb bond lengths are 2.80 Å. There are two shorter (3.21 Å) and one longer (3.84 Å) Hg–I bond lengths. In the third Hg2+ site, Hg2+ is bonded to two Sb2- and three I1- atoms to form distorted HgSb2I3 trigonal bipyramids that share corners with five HgSb2I4 octahedra, corners with two equivalent CdI4 tetrahedra, and corners with two SbHg3Sb tetrahedra. The corner-sharing octahedra tilt angles range from 3–81°. There are one shorter (2.79 Å) and one longer (2.80 Å) Hg–Sb bond lengths. There are a spread of Hg–I bond distances ranging from 2.99–3.58 Å. In the fourth Hg2+ site, Hg2+ is bonded to two equivalent Sb2- and four I1- atoms to form HgSb2I4 octahedra that share corners with two equivalent HgSb2I4 octahedra, corners with two equivalent CdI4 tetrahedra, corners with two equivalent SbHg3Sb tetrahedra, corners with two equivalent HgSb2I3 trigonal bipyramids, and edges with two equivalent HgSb2I4 octahedra. The corner-sharing octahedral tilt angles are 78°. Both Hg–Sb bond lengths are 2.78 Å. There are two shorter (3.31 Å) and two longer (3.56 Å) Hg–I bond lengths. In the fifth Hg2+ site, Hg2+ is bonded in a 5-coordinate geometry to two Sb2- and three I1- atoms. There are one shorter (2.81 Å) and one longer (2.83 Å) Hg–Sb bond lengths. There are a spread of Hg–I bond distances ranging from 2.96–3.62 Å. In the sixth Hg2+ site, Hg2+ is bonded to two Sb2- and four I1- atoms to form HgSb2I4 octahedra that share a cornercorner with one HgSb2I4 octahedra, corners with two equivalent CdI4 tetrahedra, corners with two SbHg3Sb tetrahedra, corners with two equivalent HgSb2I3 trigonal bipyramids, and an edgeedge with one HgSb2I4 octahedra. The corner-sharing octahedral tilt angles are 78°. There are one shorter (2.77 Å) and one longer (2.79 Å) Hg–Sb bond lengths. There are a spread of Hg–I bond distances ranging from 3.51–3.79 Å. In the seventh Hg2+ site, Hg2+ is bonded to two equivalent Sb2- and four I1- atoms to form HgSb2I4 octahedra that share corners with two equivalent SbHg3Sb tetrahedra, corners with four equivalent HgSb2I3 trigonal bipyramids, and edges with two equivalent CdI4 tetrahedra. Both Hg–Sb bond lengths are 2.78 Å. There are two shorter (3.69 Å) and two longer (3.72 Å) Hg–I bond lengths. Cd2+ is bonded to four I1- atoms to form CdI4 tetrahedra that share corners with three HgSb2I4 octahedra, corners with two equivalent HgSb2I3 trigonal bipyramids, and an edgeedge with one HgSb2I4 octahedra. The corner-sharing octahedra tilt angles range from 63–93°. There are a spread of Cd–I bond distances ranging from 2.83–2.88 Å. There are four inequivalent Sb2- sites. In the first Sb2- site, Sb2- is bonded to three Hg2+ and one Sb2- atom to form SbHg3Sb tetrahedra that share corners with three SbHg3Sb tetrahedra and a cornercorner with one HgSb2I3 trigonal bipyramid. The Sb–Sb bond length is 2.93 Å. In the second Sb2- site, Sb2- is bonded to three Hg2+ and one Sb2- atom to form SbHg3Sb tetrahedra that share corners with two HgSb2I4 octahedra and corners with three SbHg3Sb tetrahedra. The corner-sharing octahedra tilt angles range from 70–71°. The Sb–Sb bond length is 2.97 Å. In the third Sb2- site, Sb2- is bonded to three Hg2+ and one Sb2- atom to form SbHg3Sb tetrahedra that share a cornercorner with one HgSb2I4 octahedra and corners with three SbHg3Sb tetrahedra. The corner-sharing octahedral tilt angles are 75°. The Sb–Sb bond length is 2.93 Å. In the fourth Sb2- site, Sb2- is bonded to three Hg2+ and one Sb2- atom to form SbHg3Sb tetrahedra that share a cornercorner with one HgSb2I4 octahedra, corners with three SbHg3Sb tetrahedra, and a cornercorner with one HgSb2I3 trigonal bipyramid. The corner-sharing octahedral tilt angles are 78°. The Sb–Sb bond length is 2.90 Å. There are six inequivalent I1- sites. In the first I1- site, I1- is bonded in a 2-coordinate geometry to three Hg2+ and one Cd2+ atom. In the second I1- site, I1- is bonded in a 4-coordinate geometry to three Hg2+ and one Cd2+ atom. In the third I1- site, I1- is bonded in a 5-coordinate geometry to four Hg2+ and one Cd2+ atom. In the fourth I1- site, I1- is bonded in a distorted square co-planar geometry to four Hg2+ atoms. In the fifth I1- site, I1- is bonded in a 1-coordinate geometry to three Hg2+ and one Cd2+ atom. In the sixth I1- site, I1- is bonded in a 4-coordinate geometry to four Hg2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MgHg3 by Materials Project

MgHg3 crystallizes in the orthorhombic Pmm2 space group. The structure is three-dimensional. Mg is bonded in a 10-coordinate geometry to ten Hg atoms. There are a spread of Mg–Hg bond distances ranging from 3.14–3.25 Å. There are three inequivalent Hg sites. In the first Hg site, Hg is bonded in a 10-coordinate geometry to four equivalent Mg and six Hg atoms. There are a spread of Hg–Hg bond distances ranging from 3.10–3.27 Å. In the second Hg site, Hg is bonded in a 2-coordinate geometry to two equivalent Mg and four equivalent Hg atoms. In the third Hg site, Hg is bonded in a 4-coordinate geometry to four equivalent Mg and two equivalent Hg atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Hg3Bi by Materials Project

Hg3Bi is beta Cu3Ti-like structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. there are two inequivalent Hg sites. In the first Hg site, Hg is bonded to eight Hg and four equivalent Bi atoms to form distorted HgHg8Bi4 cuboctahedra that share corners with four equivalent BiHg12 cuboctahedra, corners with fourteen HgHg8Bi4 cuboctahedra, edges with six equivalent BiHg12 cuboctahedra, edges with twelve HgHg8Bi4 cuboctahedra, faces with four equivalent BiHg12 cuboctahedra, and faces with sixteen HgHg8Bi4 cuboctahedra. There are a spread of Hg–Hg bond distances ranging from 3.34–3.40 Å. There are two shorter (3.37 Å) and two longer (3.39 Å) Hg–Bi bond lengths. In the second Hg site, Hg is bonded to eight Hg and four equivalent Bi atoms to form distorted HgHg8Bi4 cuboctahedra that share corners with four equivalent BiHg12 cuboctahedra, corners with fourteen HgHg8Bi4 cuboctahedra, edges with six equivalent BiHg12 cuboctahedra, edges with twelve HgHg8Bi4 cuboctahedra, faces with four equivalent BiHg12 cuboctahedra, and faces with sixteen HgHg8Bi4 cuboctahedra. Both Hg–Hg bond lengths are 3.37 Å. There are two shorter (3.37 Å) and two longer (3.39 Å) Hg–Bi bond lengths. Bi is bonded to twelve Hg atoms to form BiHg12 cuboctahedra that share corners with six equivalent BiHg12 cuboctahedra, corners with twelve HgHg8Bi4 cuboctahedra, edges with eighteen HgHg8Bi4 cuboctahedra, faces with eight equivalent BiHg12 cuboctahedra, and faces with twelve HgHg8Bi4 cuboctahedra.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sr(TlHg)2 by Materials Project

Sr(HgTl)2 crystallizes in the tetragonal P4_2/mnm space group. The structure is three-dimensional. Sr is bonded in a 12-coordinate geometry to eight Hg and four equivalent Tl atoms. There are a spread of Sr–Hg bond distances ranging from 3.58–3.70 Å. All Sr–Tl bond lengths are 3.65 Å. There are two inequivalent Hg sites. In the first Hg site, Hg is bonded in a 9-coordinate geometry to four equivalent Sr, three Hg, and two equivalent Tl atoms. There are two shorter (2.91 Å) and one longer (2.92 Å) Hg–Hg bond lengths. Both Hg–Tl bond lengths are 3.17 Å. In the second Hg site, Hg is bonded in a 8-coordinate geometry to four equivalent Sr, two equivalent Hg, and two equivalent Tl atoms. Both Hg–Tl bond lengths are 3.14 Å. Tl is bonded in a 2-coordinate geometry to two equivalent Sr, two Hg, and five equivalent Tl atoms. There are one shorter (3.20 Å) and four longer (3.38 Å) Tl–Tl bond lengths.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Hg2ClO by Materials Project

Hg2OCl crystallizes in the monoclinic C2/c space group. The structure is one-dimensional and consists of two Hg2OCl ribbons oriented in the (1, 0, 1) direction. there are three inequivalent Hg+1.50+ sites. In the first Hg+1.50+ site, Hg+1.50+ is bonded in a linear geometry to two equivalent O2- atoms. Both Hg–O bond lengths are 2.04 Å. In the second Hg+1.50+ site, Hg+1.50+ is bonded in a distorted linear geometry to two equivalent O2- and two equivalent Cl1- atoms. Both Hg–O bond lengths are 2.05 Å. Both Hg–Cl bond lengths are 3.01 Å. In the third Hg+1.50+ site, Hg+1.50+ is bonded in a distorted L-shaped geometry to one O2- and one Cl1- atom. The Hg–O bond length is 2.53 Å. The Hg–Cl bond length is 2.47 Å. O2- is bonded in a distorted trigonal non-coplanar geometry to three Hg+1.50+ atoms. Cl1- is bonded in a 1-coordinate geometry to two Hg+1.50+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mg16Al12Hg by Materials Project

Mg16HgAl12 crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are ten inequivalent Mg sites. In the first Mg site, Mg is bonded in a 11-coordinate geometry to four Mg, one Hg, and six Al atoms. There are a spread of Mg–Mg bond distances ranging from 3.04–3.12 Å. The Mg–Hg bond length is 3.45 Å. There are a spread of Mg–Al bond distances ranging from 3.07–3.11 Å. In the second Mg site, Mg is bonded in a 12-coordinate geometry to seven Mg and five Al atoms. There are a spread of Mg–Mg bond distances ranging from 3.09–3.14 Å. There are a spread of Mg–Al bond distances ranging from 2.94–3.16 Å. In the third Mg site, Mg is bonded in a 1-coordinate geometry to five Mg, one Hg, and six Al atoms. There are a spread of Mg–Mg bond distances ranging from 3.07–3.37 Å. The Mg–Hg bond length is 3.03 Å. There are a spread of Mg–Al bond distances ranging from 3.06–3.18 Å. In the fourth Mg site, Mg is bonded in a 1-coordinate geometry to four Mg and twelve Al atoms. Both Mg–Mg bond lengths are 3.18 Å. There are a spread of Mg–Al bond distances ranging from 3.12–3.28 Å. In the fifth Mg site, Mg is bonded in a 12-coordinate geometry to six Mg, one Hg, and five Al atoms. There are a spread of Mg–Mg bond distances ranging from 3.06–3.26 Å. The Mg–Hg bond length is 3.11 Å. There are a spread of Mg–Al bond distances ranging from 2.88–3.18 Å. In the sixth Mg site, Mg is bonded in a 12-coordinate geometry to seven Mg and five Al atoms. There are a spread of Mg–Mg bond distances ranging from 3.11–3.16 Å. There are a spread of Mg–Al bond distances ranging from 2.89–3.25 Å. In the seventh Mg site, Mg is bonded in a 4-coordinate geometry to six Mg, one Hg, and five Al atoms. There are a spread of Mg–Mg bond distances ranging from 3.15–3.19 Å. The Mg–Hg bond length is 3.05 Å. There are a spread of Mg–Al bond distances ranging from 2.88–3.21 Å. In the eighth Mg site, Mg is bonded in a 10-coordinate geometry to four Mg and six Al atoms. There are one shorter (3.06 Å) and one longer (3.07 Å) Mg–Mg bond lengths. There are a spread of Mg–Al bond distances ranging from 3.05–3.14 Å. In the ninth Mg site, Mg is bonded in a 12-coordinate geometry to seven Mg, one Hg, and five Al atoms. The Mg–Mg bond length is 3.17 Å. The Mg–Hg bond length is 3.08 Å. There are a spread of Mg–Al bond distances ranging from 2.93–3.21 Å. In the tenth Mg site, Mg is bonded in a 12-coordinate geometry to seven Mg and five Al atoms. There are a spread of Mg–Al bond distances ranging from 2.91–3.14 Å. Hg is bonded in a 10-coordinate geometry to eight Mg and three Al atoms. There are one shorter (2.86 Å) and two longer (2.97 Å) Hg–Al bond lengths. There are seven inequivalent Al sites. In the first Al site, Al is bonded in a 11-coordinate geometry to eight Mg and three Al atoms. There are one shorter (2.71 Å) and two longer (2.73 Å) Al–Al bond lengths. In the second Al site, Al is bonded in a 11-coordinate geometry to seven Mg, one Hg, and three Al atoms. Both Al–Al bond lengths are 2.75 Å. In the third Al site, Al is bonded in a 10-coordinate geometry to seven Mg and three Al atoms. There are a spread of Al–Al bond distances ranging from 2.70–2.74 Å. In the fourth Al site, Al is bonded in a 11-coordinate geometry to seven Mg, one Hg, and three Al atoms. There are one shorter (2.70 Å) and one longer (2.77 Å) Al–Al bond lengths. In the fifth Al site, Al is bonded in a 11-coordinate geometry to eight Mg and three Al atoms. The Al–Al bond length is 2.79 Å. In the sixth Al site, Al is bonded in a 11-coordinate geometry to eight Mg and three Al atoms. The Al–Al bond length is 2.69 Å. In the seventh Al site, Al is bonded in a 11-coordinate geometry to eight Mg and three Al atoms. The Al–Al bond length is 2.74 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Mercury methylation potential and bioavailability in the sediments of two distinct aquatic systems

Here, this study explored mercury (Hg) methylation potential in two distinct aquatic systems. Fourmile Creek (FMC) was historically polluted with Hg effluents from groundwater as it is a typical gaining stream, where organic matter and microorganisms in streambed are continuously winnowed. The H02 constructed wetland only receives atmospheric Hg and is rich in organic matter and microorganisms. Both systems receive Hg from atmospheric deposition now. Surface sediments were collected from FMC and H02, spiked with inorganic Hg, and cultivated in an anaerobic chamber to stimulate microbial Hg methylation reactions. Total mercury (THg) and methylmercury (MeHg) concentrations were measured at each spiking stage. Mercury methylation potential (MMP, %MeHg in THg) and Hg bioavailability were assessed with the deployment of diffusive gradients in thin films (DGTs). During the methylation process and at the same incubation stage, FMC sediment showed faster increasing rates of %MeHg and higher MeHg concentrations than H02, demonstrating a stronger MMP in the FMC sediment. Similarly, higher Hg bioavailability was observed in FMC sediment compared to the H02 as indicated by DGT-Hg concentrations. In conclusion, the H02 wetland with high levels of organic matter and microorganisms presented low MMP. But the Fourmile Creek as a gaining stream and a historical site of Hg pollution showed strong MMP and high Hg bioavailability. A related study on microbial community activities characterized the microorganisms between FMC and H02, which is attributed to be the main reason for their different methylation capabilities. Our study further brought up the considerations on remediated sites from Hg contamination: Hg bioaccumulation and biomagnification can still be elevated and higher than the surrounding environment due to lagged changes in microbial community structures. This study supported the sustainable ecological modifications of legacy Hg contamination and raised the necessity of long-term monitoring actions even after executing a remediation plan.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2022

Mercury Accumulation in a Stream Ecosystem: Linking Labile Mercury in Sediment Porewaters to Bioaccumulative Mercury in Trophic Webs

Mercury (Hg) deposition and accumulation in the abiotic and biotic environments of a stream ecosystem were studied. This study aimed to link labile Hg in porewater to bioaccumulative Hg in biota. Sediment cores, porewaters, and biota were sampled from four sites along the Fourmile Branch (SC, USA) and measured for total Hg (THg) and methyl-Hg (MHg) concentrations. Water quality parameters were also measured at the sediment–water interface (SWI) to model the Hg speciation. In general, Hg concentrations in porewaters and bulk sediment were relatively high, and most of the sediment Hg was in the solid phase as non-labile species. Surface sediment presented higher Hg concentrations than the medium and bottom layers. Mercury methylation and MHg production in the sediment was primarily influenced by sulfate levels, since positive correlations were observed between sulfate and Hg in the porewaters. The majority of Hg species at the SWI were in non-labile form, and the dominant labile Hg species was complexed with dissolved organic carbon. MHg concentrations in the aquatic food web biomagnified with trophic levels (biofilm, invertebrates, and fish), increasing by 3.31 times per trophic level. Based on the derived data, a modified MHg magnification model was established to estimate the Hg bioaccumulation at any trophic level using Hg concentrations in the abiotic environment (i.e., porewater).

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2020

Materials Data on KHg by Materials Project

KHg is delta Molybdenum Boride-like structured and crystallizes in the triclinic P-1 space group. The structure is three-dimensional. there are two inequivalent K sites. In the first K site, K is bonded in a 7-coordinate geometry to eight Hg atoms. There are a spread of K–Hg bond distances ranging from 3.61–4.08 Å. In the second K site, K is bonded in a 7-coordinate geometry to seven Hg atoms. There are a spread of K–Hg bond distances ranging from 3.65–3.94 Å. There are two inequivalent Hg sites. In the first Hg site, Hg is bonded in a 9-coordinate geometry to seven K and two equivalent Hg atoms. There are one shorter (3.08 Å) and one longer (3.11 Å) Hg–Hg bond lengths. In the second Hg site, Hg is bonded in a 10-coordinate geometry to eight K and two equivalent Hg atoms.

36 MATERIALS SCIENCE↗