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DOE OSTI2021

Finite Element Analysis (FEA) for Water-Foam Fracturing of Granite Rock

In addition to the foam data that were obtained from literature and that were collected from the current study, simulation data was also generated from finite element analysis (FEA) conducted in this study using COMSOL Multiphysics software. The FEA models were built to simulate the experiments conducted at Oak Ridge National Laboratory (ORNL) on cement and granite samples. In these FEA models, temperature was kept at ambient while the pressure profile resembled the loading conditions during the ORNL experiments, where pressure was either monotonically increased or applied cyclically. The cement material was used as a model material and was used to study Von Mises stress and tensile stress distribution for different bore hole length geometry using a parametric sweep with water as fracturing fluid using solid-fluid interaction module. For the granite material, FEA models were developed for stress analysis of cylindrical samples with water or foam fluids. The solid mechanics module in COMSOL was implemented to solve for Von Mises stress and tensile stress. The fluid-structure interaction module was implemented to solve for water-foam interaction on granite cylinder with addition of fluid-loading on structure, i.e., large deformation in solid mechanics with no impact on fluid deformation. Foam was considered as a pseudo single-phase compressible fluid for which material properties were calculated from water and gas (nitrogen) phases. The density of foam is calculated as a function of the densities of water and nitrogen, while viscosity is a function of temperature. Four types of FEA analyses were modelled: 1. Monotonic injection with water 2. Monotonic injection with foam 3. Cyclic injection with water 4. Cyclic injection with foam All the COMSOL files are converted to a zip file which is save in .mph.

15 GEOTHERMAL ENERGY↗

DOE OSTI2022

Assessing the Impact of a Novel TBC Material on Heat Transfer in a Spark Ignition Engine through 3D CFD-FEA Co-Simulation Routine

Thermal barrier coatings (TBCs) have been of interest since the 1970s for application in internal combustion (IC) engines. Thin TBCs exhibit a temperature swing phenomenon wherein wall temperatures dynamically respond to the transient working-gas temperature throughout the engine cycle, thus reducing the temperature difference driving the heat transfer. Determining these varying wall temperatures is necessary to evaluate and study the effect of coatings on wall heat transfer. This study focuses on developing a 3D computational fluid dynamics (CFD)-finite element analysis (FEA) coupled simulation, or co-simulation, routine to determine the wall temperatures of a piston coated with a thin TBC layer subject to spark ignition combustion heat flux. A CONVERGE 3D-CFD model was used to simulate the combustion process in a single-cylinder, light-duty experimental spark ignition (SI) engine. Transient piston heat transfer analysis was conducted using ABAQUS, a FEA package, under the simulated combustion heat flux load. The effect of the temperature swing phenomenon due to this TBC layer was observed in a CFD simulation by implementing the FEA results as the piston thermal boundary conditions. The boundary conditions were passed between the CFD and FEA tools until a quasi-steady state solution was achieved. Furthermore, a reduction in wall heat transfer was observed due to a reduced temperature difference between the wall and the working gas.

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATI↗

DOE OSTI2022

Multiscale and multiphysics FEA simulation and materials optimization for laser ultrasound transducers

In this study, the relationship between the nanocomposite design and the laser ultrasound transducer (LUT) characteristics was investigated through simulations in multiple scale levels for material behavior, device response, and acoustic wave propagation in media. First, the effects of the nanoparticle size and concentration on the effective properties of composites were quantitatively investigated with the finite element analysis (FEA) method. Second, the effective properties of the nanocomposite were assigned to the layer, which is modeled as a homogeneous material, in the FEA for the LUT simulating the energy conversion from the incident laser to the acoustic wave. Finally, the ultrasound propagation in the water was calculated by a theoretical wave propagation model. The FEA-based prediction was compared with the experimental data in the literature and a theoretical analysis for LUT based on Thermal-Acoustic coupling. As a result, the ultrasound waves on the transducer surface and at a distance in the water could be predicted. Based on the hierarchically integrated prediction procedure, the optimal conditions of the photoacoustic nanocomposites were investigated through the parametric study with the particle size and concentration as variables. The results guide the material designs optimized for different device characteristics, such as high pressure and broad bandwidth.

36 MATERIALS SCIENCE↗

DOE OSTI2021

Magnetoelastic coupling, negative thermal expansion, and two-dimensional magnetic excitations in FeAs

We present a temperature-dependent investigation of the local structure and magnetic dynamics of the FeAs binary. The magnetic susceptibility χ (T) result shows an anomalous broad feature up to 550 K, with χ continuing to increase above the Néel antiferromagnetic ordering temperature (T N =70K), peaking at ~250 K, then decreasing gently above. It is remarkable that this peak susceptibility temperature corresponds to the onset of anisotropic negative thermal expansion in both the a and c axes, suggesting that magnetic interactions are affecting the structure even well above the Néel point. A systematic investigation into local bonding correlations, from time-of-flight neutron pair distribution function analyses, shows the octahedral volume around each Fe site growing monotonically while adjacent octahedra tilt toward one another before relaxing away past this peak in the anomalous magnetic susceptibility. We use inelastic-neutron scattering to map spin-wave excitations in FeAs at temperatures above and below the T N . We find magnetic excitations near T N to be very different from the excitations in the ground state at 1.5 K. Spin waves measured at 1.5 K are three dimensional (3D), however, in the vicinity of the magnetic transition, the magnetic fluctuations clearly indicate two-dimensional (2D) character in this intrinsically 3D crystal structure. Unlike the undoped 2D parents of iron-arsenide superconductors, where the magnetic correlations are considerably weaker along the c axis than in the ab plane, inelastic neutron scattering here shows that the spin fluctuations in the 3D FeAs binary are nearly 2D in the bc plane at 90 K. These results demonstrate the importance of short-range correlations in understanding the magnetic properties of transition-metal binaries, and suggest how 2D excitations, even in a 3D structure, can potentially become a breeding ground for unconventional superconductivity.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗

DOE OSTI2021

Prediction of Thermal Conditions of DED With FEA Metal Additive Simulation

This paper presents the integration of wire-arc additive manufacturing (WAAM) using Gas Metal Arc Welding (GMAW) into a machine tool to create a retrofit hybrid computer numeric control (CNC) machine tool. GMAW, along with other direct energy deposition systems, has the capacity to deposit material faster than the excess thermal energy can dissipate. This results in the need to allow the part to cool between consecutive layers, which is the most time-consuming part of the additive process. Finite element analysis (FEA) was used in conjunction with monitored build plate surface temperatures during deposition samples to improve adequate dwell time prediction and to develop a cooling system. A deposition was completed where no dwell time was used and the build plate along with the machine table temperatures were monitored. A second deposition was completed where only one bead was deposited and the traverse speed was increased. The GMAW welder was mounted on a 3-axis CNC machine where two square deposition samples were completed. A FEA model was designed and verified using the monitored samples. The model will be used to determine improved depositions speeds and whether forced cooling would allow for an increased deposition rate without structural failure. It was determined the FEA software can be used to accurately model and predict the thermal response of WAAM AM components.

Heinrich, Lauren↗

DOE OSTI2021

Design of high-deflection foils MHK applications - FEA models - RivGen Turbines

The Ocean Renewable Power Company's (ORPC's) goal is to design, develop, and test hydrofoils with large deflections. The effects of the deflections on cross-flow turbine performance would be evaluated in order to inform design considerations for full-scale water turbines and other marine hydrokinetic devices. FEA models - NASTRAN Baseline RivGen turbine Proposed new design

16 TIDAL AND WAVE POWER↗

DOE OSTI2021

Design of high-deflection foils MHK applications - FEA models - Helical turbines

16 TIDAL AND WAVE POWER↗

DOE OSTI2020

Materials Data on FeAs by Materials Project

FeAs is Modderite structured and crystallizes in the orthorhombic Pnma space group. The structure is three-dimensional. Fe3+ is bonded to six equivalent As3- atoms to form a mixture of distorted corner, edge, and face-sharing FeAs6 octahedra. The corner-sharing octahedra tilt angles range from 44–56°. There are a spread of Fe–As bond distances ranging from 2.32–2.50 Å. As3- is bonded in a 6-coordinate geometry to six equivalent Fe3+ atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Li19(FeAs)20 by Materials Project

Li19(FeAs)20 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are nineteen inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with three LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with seven LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.68–2.77 Å. In the second Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with four LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with seven LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.66–2.76 Å. In the third Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with three LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with seven LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.68–2.76 Å. In the fourth Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with four LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with eight LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.70–2.76 Å. In the fifth Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with four LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with seven LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.67–2.78 Å. In the sixth Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with four LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with eight LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.70–2.75 Å. In the seventh Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with four LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with eight LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.70–2.78 Å. In the eighth Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with three LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with seven LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.68–2.76 Å. In the ninth Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with four LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with eight LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.69–2.73 Å. In the tenth Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with four LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with eight LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.67–2.77 Å. In the eleventh Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with three LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with seven LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.68–2.78 Å. In the twelfth Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with four LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with eight LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.68–2.78 Å. In the thirteenth Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with four LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with eight LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.68–2.76 Å. In the fourteenth Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with four LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with seven LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.67–2.78 Å. In the fifteenth Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with four LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with eight LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.68–2.76 Å. In the sixteenth Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with four LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with seven LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.66–2.76 Å. In the seventeenth Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with four LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with eight LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.69–2.78 Å. In the eighteenth Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with four LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with eight LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.68–2.74 Å. In the nineteenth Li1+ site, Li1+ is bonded to five As3- atoms to form distorted LiAs5 trigonal bipyramids that share corners with twelve FeAs4 tetrahedra, corners with four LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with eight LiAs5 trigonal bipyramids. There are a spread of Li–As bond distances ranging from 2.70–2.78 Å. There are twenty inequivalent Fe+2.05+ sites. In the first Fe+2.05+ site, Fe+2.05+ is bonded to four As3- atoms to form FeAs4 tetrahedra that share corners with four FeAs4 tetrahedra, corners with eleven LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with four LiAs5 trigonal bipyramids. There are a spread of Fe–As bond distances ranging from 2.34–2.38 Å. In the second Fe+2.05+ site, Fe+2.05+ is bonded to four As3- atoms to form FeAs4 tetrahedra that share corners with four FeAs4 tetrahedra, corners with twelve LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with four LiAs5 trigonal bipyramids. There are a spread of Fe–As bond distances ranging from 2.36–2.39 Å. In the third Fe+2.05+ site, Fe+2.05+ is bonded to four As3- atoms to form FeAs4 tetrahedra that share corners with four FeAs4 tetrahedra, corners with eleven LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with four LiAs5 trigonal bipyramids. There are a spread of Fe–As bond distances ranging from 2.37–2.39 Å. In the fourth Fe+2.05+ site, Fe+2.05+ is bonded to four As3- atoms to form FeAs4 tetrahedra that share corners with four FeAs4 tetrahedra, corners with eleven LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with four LiAs5 trigonal bipyramids. There are a spread of Fe–As bond distances ranging from 2.37–2.39 Å. In the fifth Fe+2.05+ site, Fe+2.05+ is bonded to four As3- atoms to form FeAs4 tetrahedra that share corners with four FeAs4 tetrahedra, corners with twelve LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with three LiAs5 trigonal bipyramids. There are a spread of Fe–As bond distances ranging from 2.35–2.38 Å. In the sixth Fe+2.05+ site, Fe+2.05+ is bonded to four As3- atoms to form FeAs4 tetrahedra that share corners with four FeAs4 tetrahedra, corners with twelve LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with four LiAs5 trigonal bipyramids. All Fe–As bond lengths are 2.39 Å. In the seventh Fe+2.05+ site, Fe+2.05+ is bonded to four As3- atoms to form FeAs4 tetrahedra that share corners with four FeAs4 tetrahedra, corners with ten LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with four LiAs5 trigonal bipyramids. There are two shorter (2.35 Å) and two longer (2.39 Å) Fe–As bond lengths. In the eighth Fe+2.05+ site, Fe+2.05+ is bonded to four As3- atoms to form FeAs4 tetrahedra that share corners with four FeAs4 tetrahedra, corners with twelve LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with four LiAs5 trigonal bipyramids. There are a spread of Fe–As bond distances ranging from 2.37–2.40 Å. In the ninth Fe+2.05+ site, Fe+2.05+ is bonded to four As3- atoms to form FeAs4 tetrahedra that share corners with four FeAs4 tetrahedra, corners with eleven LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with four LiAs5 trigonal bipyramids. There are a spread of Fe–As bond distances ranging from 2.35–2.39 Å. In the tenth Fe+2.05+ site, Fe+2.05+ is bonded to four As3- atoms to form FeAs4 tetrahedra that share corners with four FeAs4 tetrahedra, corners with twelve LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with four LiAs5 trigonal bipyramids. There are a spread of Fe–As bond distances ranging from 2.36–2.39 Å. In the eleventh Fe+2.05+ site, Fe+2.05+ is bonded to four As3- atoms to form FeAs4 tetrahedra that share corners with four FeAs4 tetrahedra, corners with eleven LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with four LiAs5 trigonal bipyramids. There are a spread of Fe–As bond distances ranging from 2.37–2.39 Å. In the twelfth Fe+2.05+ site, Fe+2.05+ is bonded to four As3- atoms to form FeAs4 tetrahedra that share corners with four FeAs4 tetrahedra, corners with eleven LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with four LiAs5 trigonal bipyramids. There are a spread of Fe–As bond distances ranging from 2.35–2.39 Å. In the thirteenth Fe+2.05+ site, Fe+2.05+ is bonded to four As3- atoms to form FeAs4 tetrahedra that share corners with four FeAs4 tetrahedra, corners with twelve LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with four LiAs5 trigonal bipyramids. There are a spread of Fe–As bond distances ranging from 2.37–2.40 Å. In the fourteenth Fe+2.05+ site, Fe+2.05+ is bonded to four As3- atoms to form FeAs4 tetrahedra that share corners with four FeAs4 tetrahedra, corners with eleven LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with four LiAs5 trigonal bipyramids. There are a spread of Fe–As bond distances ranging from 2.35–2.40 Å. In the fifteenth Fe+2.05+ site, Fe+2.05+ is bonded to four As3- atoms to form FeAs4 tetrahedra that share corners with four FeAs4 tetrahedra, corners with twelve LiAs5 trigonal bipyramids, edges with four FeAs4 tetrahedra, and edges with three LiAs5 trigonal bipyramids. There are a spread of Fe–As bond distances ranging from 2.36–2.39 Å. In the sixteenth Fe+2.05+ site, Fe+2.05+ is bonded to four As3- atoms to form FeAs4 tetrahedra that share corners with four FeAs4 tetrahedra, corners with

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Ba4Na(FeAs)10 by Materials Project

NaBa4(FeAs)10 is alpha bismuth trifluoride-derived structured and crystallizes in the tetragonal I4/m space group. The structure is three-dimensional. Na1+ is bonded in a body-centered cubic geometry to eight equivalent As3- atoms. All Na–As bond lengths are 3.37 Å. Ba2+ is bonded in a body-centered cubic geometry to eight As3- atoms. There are a spread of Ba–As bond distances ranging from 3.36–3.43 Å. There are two inequivalent Fe+2.10+ sites. In the first Fe+2.10+ site, Fe+2.10+ is bonded to four As3- atoms to form a mixture of edge and corner-sharing FeAs4 tetrahedra. There are three shorter (2.32 Å) and one longer (2.33 Å) Fe–As bond lengths. In the second Fe+2.10+ site, Fe+2.10+ is bonded to four equivalent As3- atoms to form a mixture of edge and corner-sharing FeAs4 tetrahedra. All Fe–As bond lengths are 2.33 Å. There are two inequivalent As3- sites. In the first As3- site, As3- is bonded in a 8-coordinate geometry to one Na1+, three equivalent Ba2+, and four Fe+2.10+ atoms. In the second As3- site, As3- is bonded in a 8-coordinate geometry to four equivalent Ba2+ and four equivalent Fe+2.10+ atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on KBa4(FeAs)10 by Materials Project

KBa4(FeAs)10 is alpha bismuth trifluoride-derived structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. K1+ is bonded in a body-centered cubic geometry to eight As3- atoms. All K–As bond lengths are 3.43 Å. There are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a body-centered cubic geometry to eight As3- atoms. There are a spread of Ba–As bond distances ranging from 3.39–3.48 Å. In the second Ba2+ site, Ba2+ is bonded in a body-centered cubic geometry to eight As3- atoms. There are a spread of Ba–As bond distances ranging from 3.39–3.47 Å. There are three inequivalent Fe+2.10+ sites. In the first Fe+2.10+ site, Fe+2.10+ is bonded to four As3- atoms to form a mixture of edge and corner-sharing FeAs4 tetrahedra. There are two shorter (2.31 Å) and two longer (2.32 Å) Fe–As bond lengths. In the second Fe+2.10+ site, Fe+2.10+ is bonded to four As3- atoms to form a mixture of edge and corner-sharing FeAs4 tetrahedra. There are one shorter (2.31 Å) and three longer (2.32 Å) Fe–As bond lengths. In the third Fe+2.10+ site, Fe+2.10+ is bonded to four As3- atoms to form a mixture of edge and corner-sharing FeAs4 tetrahedra. All Fe–As bond lengths are 2.32 Å. There are three inequivalent As3- sites. In the first As3- site, As3- is bonded in a 8-coordinate geometry to one K1+, three Ba2+, and four Fe+2.10+ atoms. In the second As3- site, As3- is bonded in a 8-coordinate geometry to one K1+, three Ba2+, and four Fe+2.10+ atoms. In the third As3- site, As3- is bonded in a 8-coordinate geometry to four Ba2+ and four Fe+2.10+ atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on BaNa(FeAs)4 by Materials Project

NaBa(FeAs)4 is alpha bismuth trifluoride-derived structured and crystallizes in the orthorhombic Cmmm space group. The structure is three-dimensional. Na1+ is bonded in a body-centered cubic geometry to eight As3- atoms. All Na–As bond lengths are 3.34 Å. Ba2+ is bonded in a body-centered cubic geometry to eight As3- atoms. All Ba–As bond lengths are 3.34 Å. Fe+2.25+ is bonded to four As3- atoms to form a mixture of corner and edge-sharing FeAs4 tetrahedra. All Fe–As bond lengths are 2.32 Å. There are two inequivalent As3- sites. In the first As3- site, As3- is bonded in a 8-coordinate geometry to two equivalent Na1+, two equivalent Ba2+, and four equivalent Fe+2.25+ atoms. In the second As3- site, As3- is bonded in a 8-coordinate geometry to two equivalent Na1+, two equivalent Ba2+, and four equivalent Fe+2.25+ atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on NaSr2(FeAs)6 by Materials Project

NaSr2(FeAs)6 is alpha bismuth trifluoride-derived structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Na1+ is bonded in a body-centered cubic geometry to eight As3- atoms. There are four shorter (3.24 Å) and four longer (3.28 Å) Na–As bond lengths. Sr2+ is bonded in a body-centered cubic geometry to eight As3- atoms. There are a spread of Sr–As bond distances ranging from 3.20–3.35 Å. There are two inequivalent Fe+2.17+ sites. In the first Fe+2.17+ site, Fe+2.17+ is bonded to four As3- atoms to form a mixture of edge and corner-sharing FeAs4 tetrahedra. All Fe–As bond lengths are 2.32 Å. In the second Fe+2.17+ site, Fe+2.17+ is bonded to four As3- atoms to form a mixture of edge and corner-sharing FeAs4 tetrahedra. All Fe–As bond lengths are 2.34 Å. There are three inequivalent As3- sites. In the first As3- site, As3- is bonded in a 8-coordinate geometry to one Na1+, three equivalent Sr2+, and four Fe+2.17+ atoms. In the second As3- site, As3- is bonded in a 8-coordinate geometry to one Na1+, three equivalent Sr2+, and four equivalent Fe+2.17+ atoms. In the third As3- site, As3- is bonded in a 8-coordinate geometry to two equivalent Na1+, two equivalent Sr2+, and four Fe+2.17+ atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on KBa3(FeAs)8 by Materials Project

KBa3(FeAs)8 crystallizes in the triclinic P-1 space group. The structure is three-dimensional. K1+ is bonded in a square co-planar geometry to four As3- atoms. There are two shorter (2.86 Å) and two longer (2.87 Å) K–As bond lengths. There are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a rectangular see-saw-like geometry to four As3- atoms. There are a spread of Ba–As bond distances ranging from 2.79–2.89 Å. In the second Ba2+ site, Ba2+ is bonded in a square co-planar geometry to four As3- atoms. All Ba–As bond lengths are 2.87 Å. There are four inequivalent Fe+2.12+ sites. In the first Fe+2.12+ site, Fe+2.12+ is bonded in a 4-coordinate geometry to two Fe+2.12+ and two As3- atoms. Both Fe–Fe bond lengths are 1.97 Å. There are one shorter (2.07 Å) and one longer (2.68 Å) Fe–As bond lengths. In the second Fe+2.12+ site, Fe+2.12+ is bonded in a 4-coordinate geometry to two Fe+2.12+ and two As3- atoms. There is one shorter (1.96 Å) and one longer (1.97 Å) Fe–Fe bond length. There are one shorter (2.05 Å) and one longer (2.66 Å) Fe–As bond lengths. In the third Fe+2.12+ site, Fe+2.12+ is bonded in a 4-coordinate geometry to two Fe+2.12+ and two As3- atoms. The Fe–Fe bond length is 1.96 Å. There are one shorter (2.04 Å) and one longer (2.71 Å) Fe–As bond lengths. In the fourth Fe+2.12+ site, Fe+2.12+ is bonded in a 4-coordinate geometry to two Fe+2.12+ and two As3- atoms. There are one shorter (2.04 Å) and one longer (2.71 Å) Fe–As bond lengths. There are four inequivalent As3- sites. In the first As3- site, As3- is bonded in a 4-coordinate geometry to one K1+, one Ba2+, and two Fe+2.12+ atoms. In the second As3- site, As3- is bonded in a 4-coordinate geometry to two Ba2+ and two Fe+2.12+ atoms. In the third As3- site, As3- is bonded in a 4-coordinate geometry to one K1+, one Ba2+, and two Fe+2.12+ atoms. In the fourth As3- site, As3- is bonded in a 4-coordinate geometry to two Ba2+ and two Fe+2.12+ atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on KBa(FeAs)4 by Materials Project

KBa(FeAs)4 is alpha bismuth trifluoride-derived structured and crystallizes in the orthorhombic Cmmm space group. The structure is three-dimensional. K1+ is bonded in a body-centered cubic geometry to eight equivalent As3- atoms. All K–As bond lengths are 3.41 Å. Ba2+ is bonded in a body-centered cubic geometry to eight equivalent As3- atoms. All Ba–As bond lengths are 3.41 Å. Fe+2.25+ is bonded to four equivalent As3- atoms to form a mixture of edge and corner-sharing FeAs4 tetrahedra. All Fe–As bond lengths are 2.31 Å. As3- is bonded in a 8-coordinate geometry to two equivalent K1+, two equivalent Ba2+, and four equivalent Fe+2.25+ atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on NaSr4(FeAs)10 by Materials Project

NaSr4(FeAs)10 is alpha bismuth trifluoride-derived structured and crystallizes in the tetragonal I4/m space group. The structure is three-dimensional. Na1+ is bonded in a body-centered cubic geometry to eight equivalent As3- atoms. All Na–As bond lengths are 3.28 Å. Sr2+ is bonded in a body-centered cubic geometry to eight As3- atoms. There are a spread of Sr–As bond distances ranging from 3.25–3.32 Å. There are two inequivalent Fe+2.10+ sites. In the first Fe+2.10+ site, Fe+2.10+ is bonded to four As3- atoms to form a mixture of edge and corner-sharing FeAs4 tetrahedra. All Fe–As bond lengths are 2.32 Å. In the second Fe+2.10+ site, Fe+2.10+ is bonded to four equivalent As3- atoms to form a mixture of edge and corner-sharing FeAs4 tetrahedra. All Fe–As bond lengths are 2.32 Å. There are two inequivalent As3- sites. In the first As3- site, As3- is bonded in a 8-coordinate geometry to one Na1+, three equivalent Sr2+, and four Fe+2.10+ atoms. In the second As3- site, As3- is bonded in a 8-coordinate geometry to four equivalent Sr2+ and four equivalent Fe+2.10+ atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on K2Ba(FeAs)6 by Materials Project

K2Ba(FeAs)6 is alpha bismuth trifluoride-derived structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. K1+ is bonded in a body-centered cubic geometry to eight As3- atoms. There are a spread of K–As bond distances ranging from 3.32–3.45 Å. Ba2+ is bonded in a body-centered cubic geometry to eight As3- atoms. There are a spread of Ba–As bond distances ranging from 3.38–3.41 Å. There are two inequivalent Fe+2.33+ sites. In the first Fe+2.33+ site, Fe+2.33+ is bonded to four As3- atoms to form a mixture of corner and edge-sharing FeAs4 tetrahedra. All Fe–As bond lengths are 2.34 Å. In the second Fe+2.33+ site, Fe+2.33+ is bonded to four As3- atoms to form a mixture of corner and edge-sharing FeAs4 tetrahedra. There are two shorter (2.31 Å) and two longer (2.32 Å) Fe–As bond lengths. There are three inequivalent As3- sites. In the first As3- site, As3- is bonded in a 8-coordinate geometry to three equivalent K1+, one Ba2+, and four Fe+2.33+ atoms. In the second As3- site, As3- is bonded in a 8-coordinate geometry to three equivalent K1+, one Ba2+, and four equivalent Fe+2.33+ atoms. In the third As3- site, As3- is bonded in a 8-coordinate geometry to two equivalent K1+, two equivalent Ba2+, and four Fe+2.33+ atoms.

36 MATERIALS SCIENCE↗

DOE OSTI2020

Materials Data on Ba2Na(FeAs)6 by Materials Project

NaBa2(FeAs)6 is alpha bismuth trifluoride-derived structured and crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Na1+ is bonded in a body-centered cubic geometry to eight As3- atoms. There are a spread of Na–As bond distances ranging from 3.36–3.40 Å. Ba2+ is bonded in a body-centered cubic geometry to eight As3- atoms. There are a spread of Ba–As bond distances ranging from 3.32–3.48 Å. There are two inequivalent Fe+2.17+ sites. In the first Fe+2.17+ site, Fe+2.17+ is bonded to four As3- atoms to form a mixture of edge and corner-sharing FeAs4 tetrahedra. All Fe–As bond lengths are 2.34 Å. In the second Fe+2.17+ site, Fe+2.17+ is bonded to four As3- atoms to form a mixture of edge and corner-sharing FeAs4 tetrahedra. All Fe–As bond lengths are 2.33 Å. There are three inequivalent As3- sites. In the first As3- site, As3- is bonded in a 8-coordinate geometry to one Na1+, three equivalent Ba2+, and four Fe+2.17+ atoms. In the second As3- site, As3- is bonded in a 8-coordinate geometry to one Na1+, three equivalent Ba2+, and four equivalent Fe+2.17+ atoms. In the third As3- site, As3- is bonded in a 8-coordinate geometry to two equivalent Na1+, two equivalent Ba2+, and four Fe+2.17+ atoms.

36 MATERIALS SCIENCE↗