Engineering Papers⌕ Search

SEARCH · Engineering Papers

Results for “water structure”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,189 records · Page 66
All sourcesNASA NTRSDOE OSTI
DOE OSTI2022

Evaluation of changes in the microbial community structure in the sediments of a constructed wetland over the years

This study presents the results of the long term (2007–2014) monitoring of the microbial community structure in the surface sediments of the H-02 constructed wetland system, which was built on the Savannah River Site in Aiken, SC, USA, to treat the waste water generated at the Tritium facility. Microbial community structure provides valuable information about the functioning of constructed wetlands and helps understand the biogeochemical cycling of nutrients and contaminants. Phospholipids fatty acid (PLFA) analysis and qPCR were used to identify major bacterial phyla in the sediments. The physiochemical properties of the sediments were also used to deduce potential effects on the microbial community structure over the years. Sulfate-reducing bacteria (SRB) were the most dominant bacterial groups, and their prevalence was progressively increasing throughout the years most likely on the account of methane producers. Concentrations of trace metals (copper and zinc) were negatively associated with methane producers and oxidizer while positively correlated with SRB. Overall, the H-02 wetland system was efficient in immobilizing copper and zinc through the anaerobic respiration of sulfate by SRB and minimizing methane emission through the progressive elimination of methane producers by SRB and Geobacter. Furthermore, the aim of this study was to monitor the changes in the microbial community structure in the surface sediments of a constructed wetland during the first 7 years of operation.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2023

Evolutionary diversity of proton and water channels on the oxidizing side of photosystem II and their relevance to function

One of the reasons for the high efficiency and selectivity of biological catalysts arise from their ability to control the pathways of substrates and products using protein channels, and by modulating the transport in the channels using the interaction with the protein residues and the water/hydrogen-bonding network. Here, this process is clearly demonstrated in Photosystem II (PS II), where its light-driven water oxidation reaction catalyzed by the Mn 4 CaO 5 cluster occurs deep inside the protein complex and thus requires the transport of two water molecules to and four protons from the metal center to the bulk water. Based on the recent advances in structural studies of PS II from X-ray crystallography and cryo-electron microscopy, in this review we compare the channels that have been proposed to facilitate this mass transport in cyanobacteria, red and green algae, diatoms, and higher plants. The three major channels (O1, O4, and Cl1 channels) are present in all species investigated; however, some differences exist in the reported structures that arise from the different composition and arrangement of membrane extrinsic subunits between the species. Among the three channels, the Cl1 channel, including the proton gate, is the most conserved among all photosynthetic species. We also found at least one branch for the O1 channel in all organisms, extending all the way from Ca/O1 via the ‘water wheel’ to the lumen. However, the extending path after the water wheel varies between most species. The O4 channel is, like the Cl1 channel, highly conserved among all species while having different orientations at the end of the path near the bulk. The comparison suggests that the previously proposed functionality of the channels in T. vestitus (Ibrahim et al., Proc Natl Acad Sci USA 117:12624–12635, 2020; Hussein et al., Nat Commun 12:6531, 2021) is conserved through the species, i.e. the O1-like channel is used for substrate water intake, and the tighter Cl1 and O4 channels for proton release. The comparison does not eliminate the potential role of O4 channel as a water intake channel. However, the highly ordered hydrogen-bonded water wire connected to the Mn 4 CaO 5 cluster via the O4 may strongly suggest that it functions in proton release, especially during the S 0 → S 1 transition (Saito et al., Nat Commun 6:8488, 2015; Kern et al., Nature 563:421–425, 2018; Ibrahim et al., Proc Natl Acad Sci USA 117:12624–12635, 2020; Sakashita et al., Phys Chem Chem Phys 22:15831–15841, 2020; Hussein et al., Nat Commun 12:6531, 2021).

59 BASIC BIOLOGICAL SCIENCES↗
NASA NTRS1995

Secondary structure in solution of two anti-HIV-1 hammerhead ribozymes as investigated by two-dimensional 1H 500 MHz NMR spectroscopy in water

Two hammerhead chimeric RNA/DNA ribozymes (HRz) were synthesized in pure form. Both were 30 nucleotides long, and the sequences were such that they could be targeted to cleave the HIV-1 gag RNA. Named HRz-W and HRz-M, the former had its invariable core region conserved, the latter had a uridine in the invariable region replaced by a guanine. Their secodary structures were determined by 2D NOESY 1H 500 MHz NMR spectroscopy in 90% water and 10% D2(0), following the imino protons. The data show that both HRz-M and HRz-W form identical secondary structures with stem regions consisting of continuous stacks of AT and GT pairs. An energy minimized computer model of this stem region is provided. The results suggest that the loss of catalytic activity that is known to result when an invariant core residue is replaced is not related to the secondary structure of the ribozymes in the absence of substrate.

NASA Discipline Exobiology↗
DOE OSTI2025

Modeling the Behavior of Complex Aqueous Electrolytes Using Machine Learning Interatomic Potentials: The Case of Sodium Sulfate

Understanding the structure and thermodynamics of solvated ions is essential for advancing applications in electrochemistry, water treatment, and energy storage. While ab initio molecular dynamics methods are highly accurate, they are limited by short accessible time and length scales whereas classical force fields struggle with accuracy. Herein, we explore the structure and thermodynamics of complex monovalent-divalent ion pairs using Na 2 SO 4 (aq) as a case study by applying a machine learning interatomic potential (MLIP) trained on density functional theory (DFT) data. Our MLIP-based approach reproduces key bulk properties such as density and radial distribution functions of water. We provide the hydration structure of the sodium and sulfate ions in the 0.1–2 M concentration range and the one-dimensional and two-dimensional potentials of mean force for the sodium–sulfate ion pairing at the low concentration limit (0.1 M), which are inaccessible to DFT. At low concentrations, the sulfate ion is strongly solvated, leading to the stabilization of solvent-separated ion pairs over contact ion pairs. Minimum energy pathway analysis revealed that coordinating two sodium ions with a sulfate ion is a multistep process whereby the sodium ions coordinate to the sulfate ion sequentially. Finally, we demonstrate that MLIPs allow the study of solvated ions beyond simple monovalent pairs with DFT-level accuracy in their low concentration limit (0.1 M) via statistically converged properties from ns-long simulations.

anions↗
DOE OSTI2024

Nanopore Confinement of C-H-O Mixed-Volatile Fluids Relevant to Subsurface Energy Systems

The overarching goal of OU’s contribution to the project was to use novel computational approaches to quantify the effect of variable nanopore features (pore size, volume, topology, and chemistry) and the presence of water or salt solutions on the sorption and transport of carbon-bearing fluids. To achieve this goal OU collaborators tested test two related hypotheses: • The transport of water and aqueous electrolytes in nanopores is controlled by pore size, pore wall composition, and the type of salt – structure-maker (e.g., CaCl 2 ) versus structure-breaker (e.g., NaCl) that affect the hydrogen-bonding network. • The structure, solubility, and transport of carbon-bearing molecules in water or aqueous electrolyte-filled nanopores are controlled by the substrate type including degree of hydration, and pore features, and regulated by the hydration structure of the guest molecules.

58 GEOSCIENCES↗
DOE OSTI2025

Fouling behavior of zwitterionic membranes compared to polyamide membranes

Membrane fouling remains a critical bottleneck for reverse osmosis (RO) desalination, driving energy consumption and reducing membrane lifetime. Here, we employ all-atom molecular dynamics simulations to investigate the antifouling behavior of random zwitterionic amphiphilic copolymer (r-ZAC) membranes composed of sulfobetaine methacrylate (SBMA) and allyl methacrylate (AMA), benchmarked against conventional polyamide (PA) RO membranes. Structural and dynamical analyses—including radial distribution functions, coordination numbers, tetrahedral order parameters, vector orientation, and residence-time correlation functions—reveal that r-ZAC surfaces sustain tightly bound, long-lived hydration layers with preserved tetrahedrality and anisotropic water orientation, in sharp contrast to the weak and disordered hydration of PA. Steered molecular dynamics simulations demonstrate that r-ZAC membranes impose substantial free-energy barriers to foulant approach (alginate ≈ 90 kcal/mol, sucrose ≈ 35 kcal/mol, humic acid ≈ 15 kcal/mol), whereas PA membranes exhibit negligible barriers (< 1 kcal/mol) and thermodynamically favorable adsorption. Detailed foulant–surface interaction analyses show that zwitterionic hydration and electrostatic heterogeneity in r-ZAC suppress adhesion, except in the case of amphiphilic humic acid, which exploits multiple binding modes. Together, these results establish molecular-level design principles for antifouling membranes: the combination of zwitterionic hydration, structured interfacial water, and controlled amphiphilic balance in r-ZAC membranes provides superior resistance to organic fouling relative to PA.

Cross-linked polyamide↗
DOE OSTI2021

Hydroxyl radical yields in the heavy ion radiolysis of water

The yields of hydroxyl radicals in the radiolysis of water with protons and carbon ions have been examined using experimental scavenging techniques coupled with Monte Carlo track simulations. Combined with previous results using helium ions, this set of data gives valuable information on the potential for radiation induced damage to biological systems for light ions with very different track structures. Carbon dioxide production from aerated formic acid solutions in concentrations ranging from 10 -3 to 1 M was used as a probe of hydroxyl radical yields from about 8 ns to 8 µs. Numerical interpolation of the results at slightly different ion energies in combination with data from gamma radiolysis allows for a systematic analysis of both track average and track segment yields. As expected, considerable track chemistry is found to occur on the nanosecond to microsecond time scales. Monte Carlo track simulations employing stochastic diffusion-kinetic calculations of product yields are found to reproduce experimental observations satisfactorily. The track simulations are used to extract hydroxyl radical kinetics in pure water at neutral conditions.

38 RADIATION CHEMISTRY, RADIOCHEMISTRY, AND NUCLEA↗
DOE OSTI2023

Lagrangian and Eulerian Supersaturation Statistics in Turbulent Cloudy Rayleigh–Bénard Convection: Applications for LES Subgrid Modeling

Abstract Turbulent fluctuations of scalar and velocity fields are critical for cloud microphysical processes, e.g., droplet activation and size distribution evolution, and can therefore influence cloud radiative forcing and precipitation formation. Lagrangian and Eulerian water vapor, temperature, and supersaturation statistics are investigated in direct numerical simulations (DNS) of turbulent Rayleigh–Bénard convection in the Pi Convection Cloud Chamber to provide a foundation for parameterizing subgrid-scale fluctuations in atmospheric models. A subgrid model for water vapor and temperature variances and covariance and supersaturation variance is proposed, valid for both clear and cloudy conditions. Evaluation of phase change contributions through an a priori test using DNS data shows good performance of the model. Supersaturation is a nonlinear function of temperature and water vapor, and relative external fluxes of water vapor and heat (e.g., during entrainment-mixing and phase change) influence turbulent supersaturation fluctuations. Although supersaturation has autocorrelation and structure functions similar to the independent scalars (temperature and water vapor), the autocorrelation time scale of supersaturation differs. Relative scalar fluxes in DNS without cloud make supersaturation PDFs less skewed than the adiabatic case, where they are highly negatively skewed. However, droplet condensation changes the PDF shape response: it becomes positively skewed for the adiabatic case and negatively skewed when the sidewall relative fluxes are large. Condensation also increases correlations between water vapor and temperature in the presence of relative scalar fluxes but decreases correlations for the adiabatic case. These changes in correlation suppress supersaturation variability for the nonadiabatic cases and increase it for the adiabatic case. Implications of this work for subgrid microphysics modeling using a Lagrangian stochastic scheme are also discussed.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2020

Materials Data on Sr(H9O5)2 by Materials Project

(SrH17O9)2H2O2 crystallizes in the tetragonal P4/ncc space group. The structure is two-dimensional and consists of four water molecules and two SrH17O9 sheets oriented in the (0, 0, 1) direction. In each SrH17O9 sheet, Sr2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are four shorter (2.66 Å) and four longer (2.68 Å) Sr–O bond lengths. 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- atom. The H–O bond length is 1.00 Å. 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 (1.65 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 0.98 Å. In the fifth H1+ site, H1+ is bonded in a distorted single-bond geometry to one O2- atom. The H–O bond length is 1.01 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a water-like geometry to one Sr2+ and two H1+ atoms. In the second O2- site, O2- is bonded in a single-bond geometry to five H1+ atoms. In the third 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 Na2SiH16O11 by Materials Project

Na2Si(H7O5)2H2O crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of four water molecules and one Na2Si(H7O5)2 sheet oriented in the (1, 0, 0) direction. In the Na2Si(H7O5)2 sheet, there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Na–O bond distances ranging from 2.32–2.57 Å. In the second Na1+ site, Na1+ is bonded to six O2- atoms to form edge-sharing NaO6 octahedra. There are a spread of Na–O bond distances ranging from 2.39–2.53 Å. Si4+ is bonded in a tetrahedral geometry to four O2- atoms. There are a spread of Si–O bond distances ranging from 1.62–1.72 Å. There are fourteen 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 (1.04 Å) and one longer (1.58 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 0.97 Å. In the fourth H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.01 Å) and one longer (1.60 Å) H–O bond length. In the fifth 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 (1.66 Å) H–O bond length. 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. In the seventh 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 eighth 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 ninth H1+ site, H1+ is bonded in a distorted linear geometry to two O2- atoms. There is one shorter (1.02 Å) and one longer (1.60 Å) H–O bond length. In the tenth 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 eleventh 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 twelfth 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 thirteenth 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 fourteenth 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 ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to one Si4+ and three H1+ atoms. In the second O2- site, O2- is bonded in a distorted single-bond geometry to one Si4+ atom. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Si4+ and one H1+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+, one Si4+, and one H1+ atom. In the fifth O2- site, O2- is bonded in a distorted water-like geometry to two Na1+ and two H1+ atoms. In the sixth O2- site, O2- is bonded in a distorted water-like geometry to two equivalent Na1+ and two H1+ atoms. In the seventh O2- site, O2- is bonded in a distorted water-like geometry to two Na1+ and two H1+ atoms. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to one Na1+ and three H1+ atoms. In the ninth O2- site, O2- is bonded in a distorted water-like geometry to two Na1+ and two H1+ atoms. In the tenth O2- site, O2- is bonded in a water-like geometry to one Na1+ and two H1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Na2H16O9 by Materials Project

(Na2H15O8)2H2O2 crystallizes in the monoclinic P2_1/c space group. The structure is one-dimensional and consists of four water molecules and two Na2H15O8 ribbons oriented in the (0, 0, 1) direction. In each Na2H15O8 ribbon, there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in an octahedral geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.40–2.58 Å. In the second Na1+ site, Na1+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Na–O bond distances ranging from 2.34–2.76 Å. 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 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 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 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 1.01 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. In the seventh 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 eighth 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 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 0.98 Å. In the eleventh 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 twelfth 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 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 distorted linear geometry to two O2- atoms. There is one shorter (1.02 Å) and one longer (1.63 Å) H–O bond length. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to two H1+ atoms. In the second O2- site, O2- is bonded in a distorted water-like geometry to two Na1+ and two H1+ atoms. In the third O2- site, O2- is bonded in a water-like geometry to two Na1+ and two H1+ atoms. In the fourth O2- site, O2- is bonded in a distorted water-like geometry to two Na1+ and two H1+ atoms. In the fifth O2- site, O2- is bonded in a distorted water-like geometry to one Na1+ and two H1+ atoms. In the sixth O2- site, O2- is bonded in a distorted water-like geometry to two Na1+ and two H1+ atoms. In the seventh O2- site, O2- is bonded in a distorted water-like geometry to two Na1+ and two H1+ atoms. In the eighth O2- site, O2- is bonded in a water-like geometry to one Na1+ and two H1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on U(HO2)2 by Materials Project

UO2(OH)2 crystallizes in the orthorhombic Cmce space group. The structure is zero-dimensional and consists of four pitchblend, uranium(iv) oxide, uranium(iv) dioxide, uranium dioxide molecules and eight water molecules.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on U(HO2)2 by Materials Project

UO2(OH)2 crystallizes in the orthorhombic Cmc2_1 space group. The structure is zero-dimensional and consists of four pitchblend, uranium(iv) oxide, uranium(iv) dioxide, uranium dioxide molecules and eight water molecules.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ReSbH4O7 by Materials Project

ReSb(HO3)2H2O crystallizes in the orthorhombic Pbca space group. The structure is one-dimensional and consists of eight water molecules and four ReSb(HO3)2 ribbons oriented in the (1, 0, 0) direction. In each ReSb(HO3)2 ribbon, Re7+ is bonded in a tetrahedral geometry to four O2- atoms. There is three shorter (1.75 Å) and one longer (1.78 Å) Re–O bond length. Sb3+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Sb–O bond distances ranging from 2.00–2.50 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 1.00 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 1.01 Å. There are six inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one Re7+ atom. 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 distorted single-bond geometry to one Re7+ and one Sb3+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent Sb3+ atoms. In the fifth O2- site, O2- is bonded in a single-bond geometry to one Re7+ atom. In the sixth O2- site, O2- is bonded in a distorted water-like geometry to one Sb3+ and two H1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NdP3(H4O5)3 by Materials Project

NdP3H8O13(H2O)2 crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of eight water molecules and one NdP3H8O13 sheet oriented in the (1, 0, 0) direction. In the NdP3H8O13 sheet, Nd3+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Nd–O bond distances ranging from 2.42–2.71 Å. There are three inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one PO4 tetrahedra and a cornercorner with one PO5 trigonal bipyramid. There are a spread of P–O bond distances ranging from 1.50–1.65 Å. In the second P5+ site, P5+ is bonded to five O2- atoms to form corner-sharing PO5 trigonal bipyramids. There are a spread of P–O bond distances ranging from 1.53–1.76 Å. In the third P5+ site, P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share a cornercorner with one PO4 tetrahedra and a cornercorner with one PO5 trigonal bipyramid. There are a spread of P–O bond distances ranging from 1.50–1.63 Å. There are eight 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- atom. The H–O bond length is 1.00 Å. In the third H1+ site, H1+ is bonded in a distorted linear geometry to two O2- atoms. There is one shorter (1.00 Å) and one longer (1.54 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 distorted single-bond geometry to two O2- atoms. There is one shorter (1.01 Å) and one longer (1.64 Å) H–O bond length. 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. In the seventh 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 eighth 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 thirteen inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Nd3+ and one P5+ atom. In the second O2- site, O2- is bonded in a distorted single-bond geometry to one Nd3+ and one P5+ atom. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two P5+ atoms. In the fourth O2- site, O2- is bonded in a 1-coordinate geometry to one Nd3+, one P5+, and one H1+ atom. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to one Nd3+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to two P5+ atoms. In the seventh O2- site, O2- is bonded in a distorted single-bond geometry to one P5+ atom. In the eighth O2- site, O2- is bonded in a 3-coordinate geometry to one Nd3+, one P5+, and one H1+ atom. In the ninth O2- site, O2- is bonded in a bent 120 degrees geometry to two P5+ atoms. In the tenth O2- site, O2- is bonded in a distorted water-like geometry to one Nd3+ and two H1+ atoms. In the eleventh O2- site, O2- is bonded in a 3-coordinate geometry to one P5+ and two H1+ atoms. In the twelfth O2- site, O2- is bonded in a distorted water-like geometry to one Nd3+ and two H1+ atoms. In the thirteenth O2- site, O2- is bonded in a distorted water-like geometry to one Nd3+ and two H1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on RbUP2H8O11 by Materials Project

RbUP2(H3O5)2H2O crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of four water molecules and one RbUP2(H3O5)2 sheet oriented in the (1, 0, 0) direction. In the RbUP2(H3O5)2 sheet, Rb1+ is bonded in a 6-coordinate geometry to eight O2- atoms. There are a spread of Rb–O bond distances ranging from 2.88–3.41 Å. U3+ is bonded to seven O2- atoms to form distorted UO7 pentagonal bipyramids that share corners with five PHO3 tetrahedra. There are a spread of U–O bond distances ranging from 1.81–2.41 Å. There are two inequivalent P5+ sites. In the first P5+ site, P5+ is bonded to one H1+ and three O2- atoms to form distorted PHO3 tetrahedra that share corners with three equivalent UO7 pentagonal bipyramids. The P–H bond length is 1.41 Å. There is two shorter (1.54 Å) and one longer (1.55 Å) P–O bond length. In the second P5+ site, P5+ is bonded to one H1+ and three O2- atoms to form distorted PHO3 tetrahedra that share corners with two equivalent UO7 pentagonal bipyramids. The P–H bond length is 1.41 Å. There is one shorter (1.53 Å) and two longer (1.54 Å) P–O bond length. 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 P5+ atom. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one P5+ atom. 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 0.98 Å. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one U3+ and one P5+ atom. In the second O2- site, O2- is bonded in a 1-coordinate geometry to one Rb1+, one U3+, and one P5+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to one Rb1+ and one P5+ atom. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to one Rb1+, one U3+, and one P5+ atom. In the fifth O2- site, O2- is bonded in a distorted single-bond geometry to one U3+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a single-bond geometry to one Rb1+ and one U3+ atom. In the seventh O2- site, O2- is bonded in a single-bond geometry to one Rb1+ and one U3+ atom. In the eighth O2- site, O2- is bonded in a water-like geometry to one Rb1+ and two H1+ atoms. In the ninth O2- site, O2- is bonded in a distorted single-bond geometry to one Rb1+, one U3+, and one P5+ atom. In the tenth O2- site, O2- is bonded in a water-like geometry to one Rb1+ and two H1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Na2GeH16Se3O8 by Materials Project

Na2(H2O)7GeSe3H2O crystallizes in the monoclinic P2_1/c space group. The structure is two-dimensional and consists of four water molecules; two GeSe3 clusters; and one Na2(H2O)7 sheet oriented in the (1, 0, 0) direction. In each GeSe3 cluster, Ge4+ is bonded to four Se2- atoms to form edge-sharing GeSe4 tetrahedra. There are a spread of Ge–Se bond distances ranging from 2.34–2.47 Å. There are three inequivalent Se2- sites. In the first Se2- site, Se2- is bonded in a single-bond geometry to one Ge4+ atom. In the second Se2- site, Se2- is bonded in an L-shaped geometry to two equivalent Ge4+ atoms. In the third Se2- site, Se2- is bonded in a single-bond geometry to one Ge4+ atom. In the Na2(H2O)7 sheet, there are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded to six O2- atoms to form a mixture of corner and face-sharing NaO6 octahedra. The corner-sharing octahedra tilt angles range from 63–66°. There are a spread of Na–O bond distances ranging from 2.37–2.51 Å. In the second Na1+ site, Na1+ is bonded to six O2- atoms to form a mixture of corner and face-sharing NaO6 octahedra. The corner-sharing octahedra tilt angles range from 63–66°. There are a spread of Na–O bond distances ranging from 2.37–2.56 Å. There are fourteen 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 0.99 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. In the seventh 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 eighth 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 ninth 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 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- atom. The H–O bond length is 0.98 Å. In the thirteenth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 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. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted water-like geometry to two Na1+ and two H1+ atoms. In the second O2- site, O2- is bonded in a distorted water-like geometry to two Na1+ and two H1+ atoms. In the third O2- site, O2- is bonded in a distorted water-like geometry to two Na1+ and two H1+ atoms. In the fourth O2- site, O2- is bonded in a distorted water-like geometry to two Na1+ and two H1+ atoms. In the fifth O2- site, O2- is bonded in a distorted water-like geometry to two Na1+ and two H1+ atoms. In the sixth O2- site, O2- is bonded in a distorted water-like geometry to one Na1+ and two H1+ atoms. In the seventh O2- site, O2- is bonded in a distorted water-like geometry to one Na1+ and two H1+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on CsNa2(H5O3)3 by Materials Project

(CsNa2(H7O4)2)2H2O2 crystallizes in the orthorhombic Pca2_1 space group. The structure is three-dimensional and consists of four water molecules and one CsNa2(H7O4)2 framework. In the CsNa2(H7O4)2 framework, Cs1+ is bonded in a 3-coordinate geometry to six H1+ and seven O2- atoms. There are a spread of Cs–H bond distances ranging from 3.18–3.38 Å. There are a spread of Cs–O bond distances ranging from 3.26–3.44 Å. There are two inequivalent Na1+ sites. In the first Na1+ site, Na1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Na–O bond distances ranging from 2.34–2.51 Å. In the second Na1+ site, Na1+ is bonded in a 2-coordinate geometry to two H1+ and six O2- atoms. There are one shorter (2.54 Å) and one longer (2.56 Å) Na–H bond lengths. There are a spread of Na–O bond distances ranging from 2.28–2.54 Å. There are fourteen 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 distorted single-bond geometry to one O2- atom. The H–O bond length is 1.01 Å. In the fourth 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 fifth 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 sixth H1+ site, H1+ is bonded in a distorted single-bond geometry to one Na1+ and one O2- atom. The H–O bond length is 1.01 Å. In the seventh 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 eighth 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 ninth H1+ site, H1+ is bonded in a distorted single-bond geometry to one Cs1+ and two O2- atoms. There is one shorter (1.01 Å) and one longer (1.63 Å) H–O bond length. In the tenth H1+ site, H1+ is bonded in a distorted single-bond geometry to one Cs1+ and one O2- atom. The H–O bond length is 1.01 Å. In the eleventh H1+ site, H1+ is bonded in a distorted single-bond geometry to one Cs1+, one Na1+, and one O2- atom. The H–O bond length is 1.01 Å. In the twelfth H1+ site, H1+ is bonded in a single-bond geometry to one Cs1+ and one O2- atom. The H–O bond length is 1.00 Å. In the thirteenth H1+ site, H1+ is bonded in a distorted single-bond geometry to one Cs1+ and one O2- atom. The H–O bond length is 1.01 Å. In the fourteenth H1+ site, H1+ is bonded in a single-bond geometry to one Cs1+ and one O2- atom. The H–O bond length is 1.00 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one Cs1+ and two H1+ atoms. In the second O2- site, O2- is bonded in a single-bond geometry to one Cs1+ and one H1+ atom. In the third O2- site, O2- is bonded in a distorted water-like geometry to one Cs1+, one Na1+, and two H1+ atoms. In the fourth O2- site, O2- is bonded in a distorted water-like geometry to one Cs1+, two Na1+, and two H1+ atoms. In the fifth O2- site, O2- is bonded in a distorted water-like geometry to one Cs1+, two Na1+, and two H1+ atoms. In the sixth O2- site, O2- is bonded in a distorted water-like geometry to one Cs1+, two Na1+, and two H1+ atoms. In the seventh O2- site, O2- is bonded in a distorted water-like geometry to one Cs1+, two Na1+, and two H1+ atoms. In the eighth O2- site, O2- is bonded in a distorted water-like geometry to two Na1+ and two H1+ atoms.

36 MATERIALS SCIENCE↗