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All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

Formate as an Energy Source to Allow Sugar Fermentation with No Net CO2 Generation: Integration of Electrochemistry with Fermentation

This poster summarizes at a high-level the scope of various groups' work on Formate as an Energy Source to Allow Sugar Fermentation with No Net CO2 Generation: Integration of Electrochemistry with Fermentation. The goals of this research are to develop and demonstrate an integrated process that electrochemically generates formate from CO2 and use the formate as an energy source for the fermentation of sugars to fatty acid methyl esters (FAME) without net CO2 generation wherein formate provides reducing equivalents for sugar fermentation and a chemical looping reactor system takes advantage of intermittent low-cost electricity from wind and solar resources.

BIOMASS FUELS,INORGANIC, ORGANIC, PHYSICAL, AND AN↗
DOE OSTI2023

Techno-economic Analysis of CO2 Capture From Pulp/Paper Plants

This poster presentation evaluates the cost of capturing CO2 from a 400,000 air dried tonne (adt)/year pulp production plant, using Shell’s CANSOLV post-combustion capture process. There are five steps in a pulp/paper process: wood preparation, pulping, chemical recovery, bleaching and papermaking. There are three sources of CO2: combustion of waste wood in the wood-preparation step; combustion of black liquor, a product of pulping; and combustion of natural gas coupled with CO2 generated from calcination of limestone in the lime kiln used in chemical recovery. Standalone (pulp only) and integrated (pulp + paper) mills are modeled. The base case results and sensitivity analyses are displayed.

Mantripragada, Hari↗
DOE OSTI2024

Enhancing Electrochemical CO2 Conversion by Controlling Electrocatalysts' Structure

Electrochemical reduction of CO2 (CO2R) to valuable, carbon-neutral chemical feedstocks and storable fuels driven by renewable electricity has been recognized as one of the promising pathways to mitigate the greenhouse effect, reduce global demand for fossil fuels, achieve carbon neutrality, and create sustainable energy. Tremendous ongoing efforts have focused on controlling the morphology, composition, structure, size, defects, etc., of the electrocatalysts to improve product selectivity, activity, and durability to approach the feasibility of practical applications (current density higher than 200 mA/cm2 and lifetime ~1,000 hr+). This presentation will discuss how the geometry and surface composition of novel copper- and tin-based catalysts would maximize the CO2 conversion to carbon monoxide and liquid formic acid/formate in both common aqueous H-cell and electrolyzer configurations. Several spectroscopic, microscopic, and electrochemical characterization tools have been utilized to correlate the changes in the structural, physico-chemical, and electronic properties with the catalytic activity. Our work provides additional electrocatalyst design considerations for high-performance CO2 electrolysis.

Nguyen Phan, Thuy Duong↗
DOE OSTI2024

Carbonated Brine Injection as a Low-Risk CO2 Storage Strategy: A Case Study for Inyan Kara Sandstone Reservoir

Carbonated brine storage is a low-risk geologic CO2 sequestration strategy compared to traditional supercritical CO2 injection and storage. Our study provides an evaluation methodology for CBI that can be used for other potential pilot injections in suitable fields and opens the opportunity to work with industry for CBI using existing Class II wells to gain CO2 tax credits.

Xiong, Wei↗
DOE OSTI2021

SPRUCE Vertical Profiles of CO2 and H2O Concentrations in Air in Experimental Plots Beginning in 2015

This dataset provides a record of hourly average CO2 and H2O concentrations in air at 4 vertical locations (0.5, 1, 2, and 4 m above ground level (agl)) on the central tower location for each of 13 SPRUCE experimental plots. Ten plots have enclosures (plots 4, 6, 8, 10, 11, 13, 16, 17, 19, and 20) and three plots (5, 7 and 21) are ambients without enclosures. Data are included for measurement periods beginning in 2015 and extend throughout the whole ecosystem warming (WEW) manipulations for the SPRUCE Project (Hanson et al. 2016, 2017). In August 2015, WEW was initiated at 5 warming levels (+0, +2. +4.5, +6.75 and +9 °C) with 2 plots per warming level. DPH measurements were underway before the initiation of WEW heating treatments and both are expected to operate through 2025. Elevated CO2 treatments were initiated within 5 experimental plots (Plots 4, 10, 11, 16 and 19) in June of 2016. All measurements were made at the 8.1-ha S1 bog forest site in northern Minnesota, 40 km north of Grand Rapids, in the USDA Forest Service Marcell Experimental Forest (MEF).

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2022

CO2 CH4 flux Air temperature Soil temperature and Soil moisture, Utqiagvik (Barrow), Alaska 2013 ver. 1

This dataset consists of field measurements of CO2 and CH4 flux, as well as soil properties made during 2013 in Areas A-D of Intensive Site 1 at the Next-Generation Ecosystem Experiments (NGEE) Arctic site near Barrow, Alaska. Included are i) measurements of CO2 and CH4 flux made from June to September (ii) Calculation of corresponding Gross Primary Productivity (GPP) and CH4 exchange (transparent minus opaque) between atmosphere and the ecosystem (ii) Measurements of Los Gatos Research (LGR) chamber air temperature made from June to September (ii) measurements of surface layer depth, type of surface layer, soil temperature and soil moisture from June to September. This data package contains two *.csv files and one *.pdf file. NGEE Arctic Project Summary: The Next-Generation Ecosystem Experiments: Arctic (NGEE Arctic), was a research effort to reduce uncertainty in Earth System Models by developing a predictive understanding of carbon-rich Arctic ecosystems and feedbacks to climate. NGEE Arctic was supported by the Department of Energy's Office of Biological and Environmental Research. The NGEE Arctic project had two field research sites: 1) located within the Arctic polygonal tundra coastal region on the Barrow Environmental Observatory (BEO) and the North Slope near Utqiagvik (Barrow), Alaska and 2) multiple areas on the discontinuous permafrost region of the Seward Peninsula north of Nome, Alaska. Through observations, experiments, and synthesis with existing datasets, NGEE Arctic provided an enhanced knowledge base for multi-scale modeling and contributed to improved process representation at global pan-Arctic scales within the Department of Energy's Earth system Model (the Energy Exascale Earth System Model, or E3SM), and specifically within the E3SM Land Model component (ELM).

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2020

Environmental, Health and Safety Assessment Application of a Heat Integrated, Post-combustion CO2 Capture System Using Monoethanolamine and Hitachi H3-1 Solvent at the E.W. Brown Coal-fired Power Plant

An Environmental Health and Safety (EH&S) Assessment was completed for operation of a pilot scale carbon dioxide (CO2) capture system (CCS) at the Louisville Gas & Electric (LG&E) and Kentucky Utilities (KU) Energy, LLC (LG&E-KU) E. W. Brown Generating Station in Harrodsburg, Mercer County, Kentucky. The pilot system was evaluated using two CO2 capture solvents, monoethanolamine (MEA) and Hitachi’s H3-1 solvent. The purpose of the EH&S Assessment was to determine if there were any unacceptable environmental, health or safety concerns that may prevent operation or environmental permitting of a larger scale pilot scale plant. The assessment included review of process flow diagrams, input and output flow rates for primary materials, literature describing similar processes and chemicals used or created during the process, actual air emission and wastewater test data and air emission calculations. The evaluation included identification of risks related to hazardous chemicals, air emissions, wastewater discharges, solid wastes generated and employee hazards. Most potential EH&S issues that were identified are commonly found and successfully managed at large industrial facilities. No risks were identified that could not be successfully managed or would likely prevent implementation or environmental permitting of the pilot or larger scale plant. Potential exposures and resulting health risks from exposure to low concentrations of nitrosamines generated from degradation of the Hitachi H3-1 and possibly MEA solvents may be a health concern for site workers, but additional investigation is needed to accurately assess this risk. Applying the information gained from operating the pilot plant, performing air emission testing and used solvent testing to a large-scale facility at a commercial coal-fired electric generating plant suggests additional air emission control measures may be necessary to reduce potential site worker health risks and possibly community risks. Depending upon the location and regional air quality, considerable effort may be required to obtain the necessary air permit for construction and operation of a similarly configured large-scale PCCCS facility.

gas separation↗
DOE OSTI2022

Grey-box Fault Models and Applications for Low Carbon Emission CO2 Refrigeration System

CO2 refrigeration systems have attracted more attentions in recent years because of their zero-carbon emission advantages compared with traditional refrigerants. These systems are widely used in certain commercial buildings such as supermarkets. However, very limited energy studies have been done for such refrigeration systems under faults. Furthermore, this study investigated five common faults for supermarket transcritical CO2 refrigeration systems with display cases. The following major tasks were implemented for this study. (1) Five fault models (gray-box format) regarding the power consumption and supply air temperature were proposed for low- and high-temperature display cases, respectively. The models cover: ice accumulation on evaporator coil, evaporator fan partial failure, expansion valve failure, display door open, and condenser blockage. (2) These fault models were calibrated with field tests, and the modeling accuracies were in good agreement with measurement datasets. (3) The proposed fault models demonstrated more than 90% of fault detection for Fault Detection and Diagnostics (FDD) purposes for both field measurement and simulated data.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗
DOE OSTI2021

Experimental workflow to estimate model parameters for evaluating long term viscoelastic response of CO2 storage caprocks

Understanding the time-dependent behavior of reservoir and sealing formations is critical to assessing risks associated with geological carbon storage since time-dependent deformation strongly influences mechanical responses of some rock types. Many studies have evaluated the risk of CO2 leakage and induced seismicity by assuming poroelastic rheology in sealing formations. Few have considered viscoelastic or other time-dependent responses, where the existing literature adopts 1D models to represent long-term time-dependent responses. This is primarily because to date, the general form of a reasonable 3D time-dependent model for rocks remains unclear. In this paper, we address this unclear issue by proposing a new workflow to select constitutive modeling parameters to evaluate if a 3D viscoelastic model is reasonable using several-hour-long experimental data and a power-law response to extrapolate to the decades-long time frames of interest in geologic carbon storage. To provide experimental data, we conducted multi-level loading/unloading triaxial relaxation tests with four rock types. The experimental results showed that the maximum load relaxation observed is approximately 49%, with some rock types showing as little as 1.4%. Using a simple linear viscoelastic model, parameters were chosen such that a maximum deviation of 1.5 MPa in axial stress and 7 MPa in radial stress was attained with the extrapolated 30-year data. We found that a reasonable parameter range for the normalized elastic modulus is 0.1~2 for rocks with significant time-dependent responses and 0.01~0.06 for those with small time-dependent responses. No matter how significant time-dependent responses are for rocks considered, our results showed that the relaxation time has a general range of 1~10^10 s, whose time scale can be one or two orders higher than a time frame typically envisioned for CO2 injection projects.

Stress relaxation, 3D time-dependent model, viscoe↗
DOE OSTI2024

Model code and data: biomass allocation adjustments induced by elevated CO2 and warming in a C3 brackish marsh, 2017-2022, Maryland

This dataset and R script accompany the published paper Bruns et al. (2024) in Geophysical Research Letters. The data are from the first six years of a field manipulation of whole-ecosystem warming and elevated CO2 experiment (Salt Marsh Accretion Response to Temperature eXperiment, or SMARTX) in the Smithsonian's Global Change Research Wetland (GCReW), a brackish, microtidal wetland site on a subestuary of the Chesapeake Bay. These data were generated to understand how warming and elevated CO2 interact to structure ecosystem-level responses to global change, particularly in terms of carbon sequestration. The dataset covers 2017-2022 and includes peak annual above ground biomass, annual belowground fine root productivity, and porewater NH4 for each experimental plot. The overall experiment is replicated in two locations on the marsh, a lower elevation zone dominated the C3 sedge S. Americanus and a higher elevation plot dominated by the C4 species. This paper and its data release is only for the C3 plot. Variable descriptions for data file is available in variable_descriptions.pdf. The R script Bruns_et_al_2024_GRL_make_figures.Rmd contains model code and other scripts used to generate all paper figures.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2020

Materials Data on NaB(CO2)4 by Materials Project

NaB(CO2)4 crystallizes in the orthorhombic Cmcm space group. The structure is two-dimensional and consists of two NaB(CO2)4 sheets oriented in the (1, 0, 0) direction. Na1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.51–2.62 Å. B3+ is bonded in a tetrahedral geometry to four O2- atoms. There is two shorter (1.48 Å) and two longer (1.49 Å) B–O bond length. There are two inequivalent C3+ sites. In the first C3+ site, C3+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.22 Å) and one longer (1.33 Å) C–O bond length. In the second C3+ site, C3+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.22 Å) and one longer (1.33 Å) C–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Na1+ and one C3+ atom. In the second O2- site, O2- is bonded in a water-like geometry to one B3+ and one C3+ atom. In the third O2- site, O2- is bonded in a water-like geometry to one B3+ and one C3+ atom. In the fourth O2- site, O2- is bonded in a distorted water-like geometry to one Na1+ and one C3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Mo2H3(CO2)4 by Materials Project

Mo2H3(CO2)4 crystallizes in the orthorhombic P2_12_12_1 space group. The structure is one-dimensional and consists of four Mo2H3(CO2)4 ribbons oriented in the (1, 0, 0) direction. there are two inequivalent Mo6+ sites. In the first Mo6+ site, Mo6+ is bonded to five O2- atoms to form distorted edge-sharing MoO5 trigonal bipyramids. There are a spread of Mo–O bond distances ranging from 2.19–2.50 Å. In the second Mo6+ site, Mo6+ is bonded to five O2- atoms to form distorted edge-sharing MoO5 trigonal bipyramids. There are a spread of Mo–O bond distances ranging from 2.19–2.52 Å. There are four inequivalent C+0.25+ sites. In the first C+0.25+ site, C+0.25+ is bonded in a trigonal planar geometry to one H1+ and two O2- atoms. The C–H bond length is 1.11 Å. There is one shorter (1.27 Å) and one longer (1.28 Å) C–O bond length. In the second C+0.25+ site, C+0.25+ is bonded in a trigonal planar geometry to one H1+ and two O2- atoms. The C–H bond length is 1.10 Å. Both C–O bond lengths are 1.28 Å. In the third C+0.25+ site, C+0.25+ is bonded in a distorted bent 150 degrees geometry to two O2- atoms. Both C–O bond lengths are 1.25 Å. In the fourth C+0.25+ site, C+0.25+ is bonded in a trigonal planar geometry to one H1+ and two O2- atoms. The C–H bond length is 1.11 Å. There is one shorter (1.27 Å) and one longer (1.28 Å) C–O bond length. There are three inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one C+0.25+ atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one C+0.25+ atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to one C+0.25+ atom. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a 1-coordinate geometry to two Mo6+ and one C+0.25+ atom. In the second O2- site, O2- is bonded in a bent 120 degrees geometry to one Mo6+ and one C+0.25+ atom. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to one Mo6+ and one C+0.25+ atom. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to two Mo6+ and one C+0.25+ atom. In the fifth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Mo6+ and one C+0.25+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Mo6+ and one C+0.25+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Mo6+ and one C+0.25+ atom. In the eighth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Mo6+ and one C+0.25+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CO2 by Materials Project

CO2 crystallizes in the monoclinic P2_1/c space group. The structure is one-dimensional and consists of two CO2 ribbons oriented in the (0, 1, 0) direction. C4+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of C–O bond distances ranging from 1.19–1.40 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 120 degrees geometry to two equivalent C4+ atoms. In the second O2- site, O2- is bonded in a single-bond geometry to one C4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CO2 by Materials Project

CO2 crystallizes in the tetragonal I4_1/a space group. The structure is one-dimensional and consists of four CO2 ribbons oriented in the (0, 0, 1) direction. C4+ is bonded in a trigonal planar geometry to three O2- atoms. There are a spread of C–O bond distances ranging from 1.19–1.42 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a bent 120 degrees geometry to two equivalent C4+ atoms. In the second O2- site, O2- is bonded in a single-bond geometry to one C4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SrCuH4(CO2)4 by Materials Project

CuSr(HCOO)4 crystallizes in the monoclinic P2/c space group. The structure is one-dimensional and consists of four hydrogen molecules and two SrCuH2(CO2)4 ribbons oriented in the (1, 0, 0) direction. In each SrCuH2(CO2)4 ribbon, Sr2+ is bonded in a distorted hexagonal planar geometry to six O2- atoms. There are a spread of Sr–O bond distances ranging from 2.49–2.51 Å. Cu2+ is bonded in an L-shaped geometry to two equivalent O2- atoms. Both Cu–O bond lengths are 1.94 Å. There are two inequivalent C2+ sites. In the first C2+ site, C2+ is bonded in a distorted water-like geometry to one H1+ and one O2- atom. The C–H bond length is 1.10 Å. The C–O bond length is 1.63 Å. In the second C2+ site, C2+ is bonded in a distorted bent 120 degrees geometry to two O2- atoms. There is one shorter (1.23 Å) and one longer (1.32 Å) C–O bond length. 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 1-coordinate geometry to two C2+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to one Sr2+ and one O2- atom. The O–O bond length is 1.37 Å. In the third O2- site, O2- is bonded in a distorted single-bond geometry to one Sr2+, one Cu2+, and one O2- atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one Sr2+ and one C2+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KCr(CO2)4 by Materials Project

KCr(CO2)4 crystallizes in the monoclinic P2/c space group. The structure is one-dimensional and consists of one KCr(CO2)4 ribbon oriented in the (2, 0, -1) direction. K1+ is bonded in a 4-coordinate geometry to four O2- atoms. There are two shorter (2.74 Å) and two longer (2.76 Å) K–O bond lengths. Cr3+ is bonded in a square co-planar geometry to four O2- atoms. There is two shorter (1.94 Å) and two longer (1.95 Å) Cr–O bond length. There are two inequivalent C3+ sites. In the first C3+ site, C3+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.23 Å) and one longer (1.31 Å) C–O bond length. In the second C3+ site, C3+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.23 Å) and one longer (1.31 Å) C–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one K1+ and one C3+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to one K1+ and one C3+ atom. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to one Cr3+ and one C3+ atom. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to one Cr3+ and one C3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on MnP2H12(CO2)4 by Materials Project

MnP2H12(CO2)4 crystallizes in the triclinic P-1 space group. The structure is one-dimensional and consists of one MnP2H12(CO2)4 ribbon oriented in the (0, 1, 0) direction. there are two inequivalent Mn2+ sites. In the first Mn2+ site, Mn2+ is bonded to five O2- atoms to form distorted MnO5 trigonal bipyramids that share corners with five PO4 tetrahedra and an edgeedge with one MnO5 trigonal bipyramid. There are a spread of Mn–O bond distances ranging from 2.10–2.27 Å. In the second Mn2+ site, Mn2+ is bonded to five O2- atoms to form MnO5 trigonal bipyramids that share corners with five PO4 tetrahedra and an edgeedge with one MnO5 trigonal bipyramid. There are a spread of Mn–O bond distances ranging from 2.07–2.29 Å. There are eight inequivalent C2- sites. In the first C2- site, C2- is bonded to three H1+ and one O2- atom to form CH3O tetrahedra that share a cornercorner with one PO4 tetrahedra. All C–H bond lengths are 1.10 Å. The C–O bond length is 1.45 Å. In the second C2- site, C2- is bonded to three H1+ and one O2- atom to form CH3O tetrahedra that share a cornercorner with one PO4 tetrahedra. All C–H bond lengths are 1.10 Å. The C–O bond length is 1.44 Å. In the third C2- site, C2- is bonded to three H1+ and one O2- atom to form CH3O tetrahedra that share a cornercorner with one PO4 tetrahedra. All C–H bond lengths are 1.10 Å. The C–O bond length is 1.45 Å. In the fourth C2- site, C2- is bonded to three H1+ and one O2- atom to form CH3O tetrahedra that share a cornercorner with one PO4 tetrahedra. There is one shorter (1.09 Å) and two longer (1.10 Å) C–H bond length. The C–O bond length is 1.45 Å. In the fifth C2- site, C2- is bonded to three H1+ and one O2- atom to form CH3O tetrahedra that share a cornercorner with one PO4 tetrahedra. All C–H bond lengths are 1.10 Å. The C–O bond length is 1.45 Å. In the sixth C2- site, C2- is bonded to three H1+ and one O2- atom to form CH3O tetrahedra that share a cornercorner with one PO4 tetrahedra. There is one shorter (1.09 Å) and two longer (1.10 Å) C–H bond length. The C–O bond length is 1.45 Å. In the seventh C2- site, C2- is bonded to three H1+ and one O2- atom to form CH3O tetrahedra that share a cornercorner with one PO4 tetrahedra. All C–H bond lengths are 1.10 Å. The C–O bond length is 1.44 Å. In the eighth C2- site, C2- is bonded to three H1+ and one O2- atom to form CH3O tetrahedra that share a cornercorner with one PO4 tetrahedra. All C–H bond lengths are 1.10 Å. The C–O bond length is 1.45 Å. There are four inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two CH3O tetrahedra and corners with two MnO5 trigonal bipyramids. There is two shorter (1.51 Å) and two longer (1.62 Å) P–O bond length. In the second P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two CH3O tetrahedra and corners with three MnO5 trigonal bipyramids. There are a spread of P–O bond distances ranging from 1.50–1.61 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two CH3O tetrahedra and corners with three MnO5 trigonal bipyramids. There are a spread of P–O bond distances ranging from 1.51–1.61 Å. In the fourth P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with two CH3O tetrahedra and corners with two MnO5 trigonal bipyramids. There is two shorter (1.50 Å) and two longer (1.62 Å) P–O bond length. There are twenty-four 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. In the third H1+ site, H1+ is bonded in a single-bond geometry to one C2- atom. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one C2- atom. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one C2- atom. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one C2- atom. In the seventh H1+ site, H1+ is bonded in a single-bond geometry to one C2- atom. In the eighth H1+ site, H1+ is bonded in a single-bond geometry to one C2- atom. In the ninth H1+ site, H1+ is bonded in a single-bond geometry to one C2- atom. In the tenth H1+ site, H1+ is bonded in a single-bond geometry to one C2- atom. In the eleventh H1+ site, H1+ is bonded in a single-bond geometry to one C2- atom. In the twelfth H1+ site, H1+ is bonded in a single-bond geometry to one C2- atom. In the thirteenth H1+ site, H1+ is bonded in a single-bond geometry to one C2- atom. In the fourteenth H1+ site, H1+ is bonded in a single-bond geometry to one C2- atom. In the fifteenth H1+ site, H1+ is bonded in a single-bond geometry to one C2- atom. In the sixteenth H1+ site, H1+ is bonded in a single-bond geometry to one C2- atom. In the seventeenth H1+ site, H1+ is bonded in a single-bond geometry to one C2- atom. In the eighteenth H1+ site, H1+ is bonded in a single-bond geometry to one C2- atom. In the nineteenth H1+ site, H1+ is bonded in a single-bond geometry to one C2- atom. In the twentieth H1+ site, H1+ is bonded in a single-bond geometry to one C2- atom. In the twenty-first H1+ site, H1+ is bonded in a single-bond geometry to one C2- atom. In the twenty-second H1+ site, H1+ is bonded in a single-bond geometry to one C2- atom. In the twenty-third H1+ site, H1+ is bonded in a single-bond geometry to one C2- atom. In the twenty-fourth H1+ site, H1+ is bonded in a single-bond geometry to one C2- atom. There are sixteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Mn2+ and one P5+ atom. In the second O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Mn2+ and one P5+ atom. In the third O2- site, O2- is bonded in a bent 120 degrees geometry to one C2- and one P5+ atom. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to one C2- and one P5+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to two Mn2+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Mn2+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a bent 120 degrees geometry to one C2- and one P5+ atom. In the eighth O2- site, O2- is bonded in a bent 120 degrees geometry to one C2- and one P5+ atom. In the ninth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Mn2+ and one P5+ atom. In the tenth O2- site, O2- is bonded in a 3-coordinate geometry to two Mn2+ and one P5+ atom. In the eleventh O2- site, O2- is bonded in a bent 120 degrees geometry to one C2- and one P5+ atom. In the twelfth O2- site, O2- is bonded in a bent 120 degrees geometry to one C2- and one P5+ atom. In the thirteenth O2- site, O2- is bonded in a bent 150 degrees geometry to one Mn2+ and one P5+ atom. In the fourteenth O2- site, O2- is bonded in a bent 150 degrees geometry to one Mn2+ and one P5+ atom. In the fifteenth O2- site, O2- is bonded in a bent 120 degrees geometry to one C2- and one P5+ atom. In the sixteenth O2- site, O2- is bonded in a bent 120 degrees geometry to one C2- and one P5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Np(CO2)4 by Materials Project

Np(CO2)4 is Protactinium structured and crystallizes in the tetragonal I-4 space group. The structure is zero-dimensional and consists of two Np(CO2)4 clusters. Np6+ is bonded in a distorted body-centered cubic geometry to eight O2- atoms. There are four shorter (2.39 Å) and four longer (2.57 Å) Np–O bond lengths. C+2.50+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.24 Å) and one longer (1.26 Å) C–O bond length. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to one Np6+ and one C+2.50+ atom. The O–Np bond length is 2.57 Å. The O–C bond length is 1.24 Å. In the second O2- site, O2- is bonded in a distorted L-shaped geometry to one Np6+ and one C+2.50+ atom. The O–Np bond length is 2.39 Å. The O–C bond length is 1.26 Å.

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