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All sourcesNASA NTRSDOE OSTI
NASA NTRS2004

Orbit Optimization For The Geospace Electrodynamics Connections (GEC) Mission

Part of NASA's Solar Terrestrial Probe line of missions, the Geospace Electrodynamics Connections (GEC) mission will deploy a formation of three spacecraft to perform in-situ atmospheric research in the low Ionosphere-Thermosphere region. These spacecraft will fly together in a %tring-of-pearls formation with variable spacings ranging from 10 seconds to one-quarter of an orbit at perigee. Over the course of its two-year mission, the three spacecraft will perform ten, 1-week dipping campaigns whereby they maneuver to lower their perigee to near 134 km. Using available launch vehicle performance data, an optimal parking orbit of 222 x 1525 km was found to maximize the dry mass available while providing enough propellant to perform the ten deep-dipping campaigns over its two-year mission. The results were used to create multi-variable contour plots containing the orbit perigee, the orbit apogee, spacecraft dry mass, propellant mass, and T500 (a science data collection figure of merit that tabulates the cumulative time spent below 500 km). These plots illustrate how the mission can trade off science return relative to the cost in dry mass and propellant. Other optimal solutions such as minimum propellant or maximum T500 were found to either limit the science data collection or to be dry mass limiting, respectively. Sensitivity analyses were performed to find new optimal (maximum dry mass) solutions if the number of campaigns changed, if the coefficient of drag (CD) were different, and if the propellant specific impulse were increased. A surprising result showed that the dry mass and T500 were both increased if the number of campaigns decreased. Changes in CD provided the expected results - raising CD lowered both the dry mass and T500 while lowering CD raised both the dry mass and T500. Increases in the propellant specific impulse had the expected outcome of raising the dry mass and lowering the propellant load but there was no change in the T500 figure of merit. The orbit optimization was performed parametrically using a Matlab(TradeMark) script and validated using FreeFlyer(TradeMark), a commercial orbit analysis tool. ,

Mesarch, Michael A.↗
NASA NTRS2004

Accelerated Training at Mach 20: A Brief Communication Submitted from the International Space Station

The performance of complex tasks on the International Space Station (ISS) requires significant preflight crew training commitments and frequent skill and knowledge refreshment. This report documents a recently developed just-in-time training methodology, which integrates preflight hardware familiarization and procedure training with an on-orbit CD-ROM-based skill enhancement. This just-in-time concept was used to support real-time remote expert guidance to complete medical examinations using the ISS Human Research Facility (HRF). An American and Russian ISS crewmember received 2-hours of hands on ultrasound training 8 months prior to the on-orbit ultrasound exam. A CD-ROM-based Onboard Proficiency Enhancement (OPE) interactive multimedia program consisting of memory enhancing tutorials, and skill testing exercises, was completed by the crewmember six days prior to the on-orbit ultrasound exam. The crewmember was then remotely guided through a thoracic, vascular, and echocardiographic examination by ultrasound imaging experts. Results of the CD ROM based OPE session were used to modify the instructions during a complete 35 minute real-time thoracic, cardiac, and carotid/jugular ultrasound study. Following commands from the ground-based expert, the crewmember acquired all target views and images without difficulty. The anatomical content and fidelity of ultrasound video were excellent and adequate for clinical decision-making. Complex ultrasound experiments with expert guidance were performed with high accuracy following limited pre-flight training and CD-ROM-based in-flight review, despite a 2-second communication latency. In-flight application of multimedia proficiency enhancement software, coupled with real-time remote expert guidance, can facilitate the performance of complex demanding tasks.

Foale, C. Michael↗
NASA NTRS2004

Stereomotion speed perception: contributions from both changing disparity and interocular velocity difference over a range of relative disparities

The role of two binocular cues to motion in depth-changing disparity (CD) and interocular velocity difference (IOVD)- was investigated by measuring stereomotion speed discrimination and static disparity discrimination performance (stereoacuity). Speed discrimination thresholds were assessed both for random dot stereograms (RDS), and for their temporally uncorrelated equivalents, dynamic random dot stereograms (DRDS), at relative disparity pedestals of -19, 0, and +19 arcmin. While RDS stimuli contain both CD and IOVD cues, DRDS stimuli carry only CD information. On average, thresholds were a factor of 1.7 higher for DRDS than for RDS stimuli with no clear effect of relative disparity pedestal. Results were similar for approaching and receding targets. Variations in stimulus duration had no significant effect on thresholds, and there was no observed correlation between stimulus displacement and perceived speed, confirming that subjects responded to stimulus speed in each condition. Stereoacuity was equally good for our RDS and DRDS stimuli, showing that the difference in stereomotion speed discrimination performance for these stimuli was not due to any difference in the precision of the disparity cue. In addition, when we altered stereomotion stimulus trajectory by independently manipulating the speeds and directions of its monocular half-images, perceived stereomotion speed remained accurate. This finding is inconsistent with response strategies based on properties of either monocular half-image motion, or any ad hoc combination of the monocular speeds. We conclude that although subjects are able to discriminate stereomotion speed reliably on the basis of CD information alone, IOVD provides a precise additional cue to stereomotion speed perception.

Depth Perception/physiology↗
NASA NTRS2006

Human Space Flight

The performance of complex tasks on the International Space Station (ISS) requires significant preflight crew training commitments and frequent skill and knowledge refreshment. This report documents a recently developed just-in-time training methodology, which integrates preflight hardware familiarization and procedure training with an on-orbit CD-ROM-based skill enhancement. This just-in-time concept was used to support real-time remote expert guidance to complete medical examinations using the ISS Human Research Facility (HRF). An American md Russian ISS crewmember received 2-hours of hands on ultrasound training 8 months prior to the on-orbit ultrasound exam. A CD-ROM-based Onboard Proficiency Enhancement (OPE) interactive multimedia program consisting of memory enhancing tutorials, and skill testing exercises, was completed by the crewmember six days prior to the on-orbit ultrasound exam. The crewmember was then remotely guided through a thoracic, vascular, and echocardiographic examination by ultrasound imaging experts. Results of the CD ROM based OPE session were used to modify the instructions during a complete 35 minute real-time thoracic, cardiac, and carotid/jugular ultrasound study. Following commands from the ground-based expert, the crewmember acquired all target views and images without difficulty. The anatomical content and fidelity of ultrasound video were excellent and adequate for clinical decision-making. Complex ultrasound experiments with expert guidance were performed with high accuracy following limited pre-flight training and CD-ROM-based in-flight review, despite a 2-second communication latency.

Woolford, Barbara↗
NASA NTRS1986

Reactively-sputtered zinc semiconductor films of high conductivity for heterojunction devices

A high conductivity, n-doped semiconductor film is produced from zinc, or Zn and Cd, and group VI elements selected from Se, S and Te in a reactive magnetron sputtering system having a chamber with one or two targets, a substrate holder, means for heating the substrate holder, and an electric field for ionizing gases in the chamber. Zinc or a compound of Zn and Cd is placed in the position of one of the two targets and doping material in the position of the other of the two targets. Zn and Cd may be placed in separate targets while a dopant is placed in the third target. Another possibility is to place an alloy of Zn and dopant, or Zn, Cd and dopant in one target, thus using only one target. A flow of the inert gas is ionized and directed toward said targets, while a flow of a reactant gas consisting of hydrides of the group VI elements is directed toward a substrate on the holder. The targets are biased to attract negatively ionized inert gas. The desired stochiometry for high conductivity is achieved by controlling the temperature of the substrate, and partial pressures of the gases, and the target power and total pressure of the gases in the chamber.

Stirn, Richard J.↗
NASA NTRS2008

A Performance Assessment of an Airborne Separation Assistance System Using Realistic Complex Traffic Flows

This paper presents the results from a study that investigates the performance of a tactical Airborne Separation Assistance System (ASAS) in en route airspace, under varying demand levels, with realistic traffic flows. The ASAS concept studied here allows flight crews of equipped aircraft to perform separation from other air traffic autonomously. This study addresses the tactical aspects of an ASAS using aircraft state data (i.e. position and velocity) to detect and resolve projected conflicts. In addition, use of a conflict prevention system helps ASAS-equipped aircraft avoid maneuvers that may cause new conflicts. ASAS-capable aircraft are equipped with satellite-based navigation and Automatic Dependent Surveillance Broadcast (ADS-B) for transmission and receipt of aircraft state data. In addition to tactical conflict detection and resolution (CD&R), a complete, integrated ASAS is likely to incorporate a strategic CD&R component with a longer look-ahead time, using trajectory intent information. A system-wide traffic flow management (TFM) component, located at the FAA command center helps aircraft to avoid regions of excessive traffic density and complexity. A Traffic Alert and Collision Avoidance System (TCAS), as used today is the system of last resort. This integrated approach avoids sole reliance on the use of the tactical CD&R studied here, but the tactical component remains a critical element of the complete ASAS. The focus of this paper is to determine to what extent the proposed tactical component of ASAS alone can maintain aircraft separation at demand levels up to three times that of current traffic. The study also investigates the effect of mixing ASAS-equipped aircraft with unequipped aircraft (i.e. current day) that do not have the capability to self-separate. Position and velocity data for unequipped aircraft needs to be available to ASASequipped. Most likely, for this future concept, state data would be available from instrument flight rules (IFR) aircraft, equipped with at least ADS-B transmission capability. The objective is to reduce the number of losses of separation to a minimum and investigate the limits of tactical-only CD&R. Thus, the objective is not, expressly, to achieve zero losses of separation with tactical ASAS because this is one component of an integrated ASAS.

Smith, Jeremy C.↗
NASA NTRS2012

Airport Traffic Conflict Detection and Resolution Algorithm Evaluation

A conflict detection and resolution (CD&R) concept for the terminal maneuvering area (TMA) was evaluated in a fast-time batch simulation study at the National Aeronautics and Space Administration (NASA) Langley Research Center. The CD&R concept is being designed to enhance surface situation awareness and provide cockpit alerts of potential conflicts during runway, taxi, and low altitude air-to-air operations. The purpose of the study was to evaluate the performance of aircraft-based CD&R algorithms in the TMA, as a function of surveillance accuracy. This paper gives an overview of the CD&R concept, simulation study, and results. The Next Generation Air Transportation System (NextGen) concept for the year 2025 and beyond envisions the movement of large numbers of people and goods in a safe, efficient, and reliable manner [1]. NextGen will remove many of the constraints in the current air transportation system, support a wider range of operations, and provide an overall system capacity up to three times that of current operating levels. Emerging NextGen operational concepts [2], such as four-dimensional trajectory based airborne and surface operations, equivalent visual operations, and super density arrival and departure operations, require a different approach to air traffic management and as a result, a dramatic shift in the tasks, roles, and responsibilities for the flight deck and air traffic control (ATC) to ensure a safe, sustainable air transportation system.

Jones, Denise R.↗
NASA NTRS2013

NASA Models of Space Radiation Induced Cancer, Circulatory Disease, and Central Nervous System Effects

The risks of late effects from galactic cosmic rays (GCR) and solar particle events (SPE) are potentially a limitation to long-term space travel. The late effects of highest concern have significant lethality including cancer, effects to the central nervous system (CNS), and circulatory diseases (CD). For cancer and CD the use of age and gender specific models with uncertainty assessments based on human epidemiology data for low LET radiation combined with relative biological effectiveness factors (RBEs) and dose- and dose-rate reduction effectiveness factors (DDREF) to extrapolate these results to space radiation exposures is considered the current "state-of-the-art". The revised NASA Space Risk Model (NSRM-2014) is based on recent radio-epidemiology data for cancer and CD, however a key feature of the NSRM-2014 is the formulation of particle fluence and track structure based radiation quality factors for solid cancer and leukemia risk estimates, which are distinct from the ICRP quality factors, and shown to lead to smaller uncertainties in risk estimates. Many persons exposed to radiation on earth as well as astronauts are life-time never-smokers, which is estimated to significantly modify radiation cancer and CD risk estimates. A key feature of the NASA radiation protection model is the classification of radiation workers by smoking history in setting dose limits. Possible qualitative differences between GCR and low LET radiation increase uncertainties and are not included in previous risk estimates. Two important qualitative differences are emerging from research studies. The first is the increased lethality of tumors observed in animal models compared to low LET radiation or background tumors. The second are Non- Targeted Effects (NTE), which include bystander effects and genomic instability, which has been observed in cell and animal models of cancer risks. NTE's could lead to significant changes in RBE and DDREF estimates for GCR particles, and the potential effectiveness of radiation mitigator's. The NSRM- 2014 approaches to model radiation quality dependent lethality and NTE's will be described. CNS effects include both early changes that may occur during long space missions and late effects such as Alzheimer's disease (AD). AD effects 50% of the population above age 80-yr, is a degenerative disease that worsens with time after initial onset leading to death, and has no known cure. AD is difficult to detect at early stages and the small number of low LET epidemiology studies undertaken have not identified an association with low dose radiation. However experimental studies in mice suggest GCR may lead to early onset AD. We discuss modeling approaches to consider mechanisms whereby radiation would lead to earlier onset of occurrence of AD. Biomarkers of AD include amyloid beta (A(Beta)) plaques, and neurofibrillary tangles (NFT) made up of aggregates of the hyperphosphorylated form of the micro-tubule associated, tau protein. Related markers include synaptic degeneration, dentritic spine loss, and neuronal cell loss through apoptosis. Radiation may affect these processes by causing oxidative stress, aberrant signaling following DNA damage, and chronic neuroinflammation. Cell types to be considered in multi-scale models are neurons, astrocytes, and microglia. We developed biochemical and cell kinetics models of DNA damage signaling related to glycogen synthase kinase-3(Beta) (GSK3(Beta)) and neuroinflammation, and considered multi-scale modeling approaches to develop computer simulations of cell interactions and their relationships to A(Beta) plaques and NFTs. Comparison of model results to experimental data for the age specific development of A(Beta) plaques in transgenic mice will be discussed.

Cucinotta, Francis A.↗
NASA NTRS2013

Initial Concept for Terminal Area Conflict Detection, Alerting, and Resolution Capability On or Near the Airport Surface, Version 2.0

The Next Generation Air Transportation System (NextGen) concept for 2025 envisions the movement of large numbers of people and goods in a safe, efficient, and reliable manner. The NextGen will remove many of the constraints in the current air transportation system, support a wider range of operations, and deliver an overall system capacity up to 3 times that of current operating levels. In order to achieve the NextGen vision, research is necessary in the areas of surface traffic optimization, maximum runway capacity, reduced runway occupancy time, simultaneous single runway operations, and terminal area conflict prevention, among others. The National Aeronautics and Space Administration (NASA) is conducting Collision Avoidance for Airport Traffic (CAAT) research to develop technologies, data, and guidelines to enable Conflict Detection and Resolution (CD&R) in the Airport Terminal Maneuvering Area (ATMA) under current and emerging NextGen operating concepts. The term ATMA was created to reflect the fact that the CD&R concept area of operation is focused near the airport within the terminal maneuvering area. In the following, an initial concept for an aircraft-based method for CD&R in the ATMA is presented. This method is based upon previous NASA work in CD&R for runway incursion prevention, the Runway Incursion Prevention System (RIPS).

Otero, Sharon D.↗
NASA NTRS2014

Growth of CdZnTe Crystals for Radiation Detector Applications by Directional Solidification

Advances in Cadmium Zinc Telluride (Cd(sub 1-x)Zn(sub x)Te) growth techniques are needed for the production of large-scale arrays of gamma and x-ray astronomy. The research objective is to develop crystal growth recipes and techniques to obtain large, high quality CdZnTe single crystal with reduced defects, such as charge trapping, twinning, and tellurium precipitates, which degrade the performance of CdZnTe and, at the same time, to increase the yield of usable material from the CdZnTe ingot. A low gravity material experiment, "Crystal Growth of Ternary Compound Semiconductors in Low Gravity Environment", will be performed in the Material Science Research Rack (MSRR) on International Space Station (ISS). One section of the flight experiment is the melt growth of CdZnTe ternary compounds. This talk will focus on the ground-based studies on the growth of Cd(sub 0.80)Zn(sub 0.20)Te crystals for radiation detector applications by directional solidification. In this investigation, we have improved the properties that are most critical for the detector applications (electrical properties and crystalline quality): a) Electrical resistivity: use high purity starting materials (with reproducible impurity levels) and controlled Cd over pressure during growth to reproducibly balance the impurity levels and Cd vacancy concentration b) Crystalline quality: use ultra-clean growth ampoule (no wetting after growth), optimized thermal profile and ampoule design, as well as a technique for supercool reduction to growth large single crystal with high crystalline quality

Su, Ching-Hua↗
DOE OSTI2019

Design, Construction, and Commissioning of the RH LLW Disposal Facility at INL - 19445

The newly-commissioned Remote-Handled Low-Level Waste (RH LLW) Disposal Facility at Idaho National Laboratory (INL) provides permanent disposal capability critical for continuing INL nuclear research and Naval Reactors missions at the Idaho site. The facility mission need [critical decision (CD)- 0] was approved in 2009. Alternative selection (CD-1) was finalized in 2011. The project performance baseline (CD-2/3) was approved and design was initiated in 2014 and construction began in 2015. Construction was completed and transitioned to Materials and Fuels Complex (MFC) Operations in 2017. The facility successfully achieved readiness with authorization to begin operations (CD-4) in 2018. The $77 M line-item capital-acquisition project was completed six months ahead of the congressional commitment date and significantly under budget. This paper presents highlights of the RH LLW Disposal Facility project delivery and a summary of facility features and critical characteristics. Highlights include: - As a hazard category II nuclear facility, the project complied with United States Department of Energy (DOE) requirements for incorporation of nuclear safety into facility design and construction as identified in DOE-STD-1189 as well as 10 CFR 835 Subpart K requirements for incorporation of ALARA principles in facility design. - From an environmental compliance perspective, the facility was subject to National Environmental Policy Act requirements resulting in a Finding of No Significant Impact as determined by an Environmental Assessment. An operating disposal authorization statement from the Low-Level Waste Disposal Facility Federal Review Group (LFRG) authorizing waste disposal operations in accordance with DOE Order 435.1 was obtained. - The project was delivered using a design-build delivery method with a firm-fixed price with incentive fee contracting mechanism. The project was executed as a line-item capital-acquisition project, in full compliance with DOE Order 413.3B under INL's certified Earned Value Management System (EVMS) program. - The facility supports twenty years of waste disposal operations with five disposal vault configurations in four vault arrays supporting six different cask/canister system configurations. Three of the six cask/canister systems currently exist and three will be developed to support future operations. There are a total of 446 waste disposal vaults that will accommodate disposal of a total of 939 stainless steel radioactive waste canisters. The facility is designed to accommodate canisters with contact radiation dose rates as high as 600 Sievert/hour (60,000 Rem/hour). - The facility underwent a rigorous readiness review process in accordance with DOE Order 425.1D. Readiness activities included rigorous facility testing and shakedown activities, a management-self assessment, a contractor operational readiness review, and a DOE operational readiness review. Readiness was demonstrated for an existing cask/canister system (the MFC HFEF-5 cask). Separate readiness activities will be conducted for each cask/canister system as they are brought online for facility operations. INL's successful delivery of the project has provided waste disposal capability to ensure long-term viability of planned and current facilities and missions associated with both INL and the Naval Reactors Facility. Successful execution of the project has proven to be strategically important to future capital investments in capabilities necessary to advance INL's mission. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2020

WIPP Safety Significant Confinement Ventilation System (SSCVS) Quality Assurance Program - 20237

Construction and major equipment fabrication are underway for a new ventilation exhaust system at the Waste Isolation Pilot Plant (WIPP). The new system will provide continuous HEPA filtration of the exhaust from the WIPP underground while meeting the ventilation demands for expanded waste emplacement and mining operations over the next 40 years. The SSCVS project has proceeded with the awarding of CD-3A for Long Lead Procurements followed by CD-2/3 approval for the construction of the facilities. The SSCVS project team made the decision to increase the quality oversight throughout the complete project per the Project Quality Assurance Plan (PQAP) such that it can ensure the final products meet applicable NQA-1 requirements and general quality requirements, and that the project will proceed to operations without significant delays due to post installation quality concerns. The PQAP was established prior to approval of the project at the CD-2/3 milestone. The SSCVS project has 2 major long lead procurements which commenced with the awarding of CD-3A. These procurements include the HEPA filter housing assemblies and the Exhaust Fans. There are 22 HEPA filter assemblies for the SSCVS, which are designated Safety Significant for pressure boundary confinement, per the approved PDSA. The exhaust fans also have Safety Significant components to maintain the pressure confinement boundary. NWP made the decision to install resident Quality Inspectors at the fabrication facilities to ensure the documentation for each fabricated unit meets all the QA requirements as defined in the respective contract documents. For the construction of the SSCVS Salt Reduction Building (SRB) and New Filter Building (NFB), dedicated, on-site quality inspectors have been utilized to ensure that all work being performed will comply with quality requirements and the Special Inspections as defined in IBC-2015. At each stage of inspection, hold points are placed into the work packages to ensure NWP QA personnel are present to inspect and verify the installations are in accordance with the design specifications, codes and standards. With this level of oversight, NWP anticipates that the level of quality related issues, as seen on multiple other DOE complex site projects, will be avoided and that the commissioning, start-up and hot operations will progress in a timely fashion, as all documentation will be in place and approved prior to initiation of these activities. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2018

Capturing the variable reactivity of goethites in surface complexation modeling by correlating model parameters with specific surface area

The development of predictive tools capable of simulating adsorption behavior on goethite (α-FeOOH) surfaces has evolved over the past several decades. Recent research has focused on capturing the variation of surface reactivity and adsorption behavior for different preparations of synthetic goethites. Here in this research, an approach to estimate modeling parameters based on the specific surface area (SSA) of goethites was established and combined with a Charge Distribution – Multi-site Complexation (CD-MUSIC) surface complexation model. It was assumed that differences in crystal face contributions (CFC), inner-Helmholtz capacitances (C 1 ), and protonation constants of surface oxygens (pK a ’s) among different preparations of goethite contribute to the variation of surface reactivity. Thus, correlations of these modeling parameters with the SSA of a range of goethites were identified by comprehensively combining microscopic, macroscopic, and modeling data reported in literature along with adsorption data collected from macroscopic experiments conducted as part of this study. A CD-MUSIC model shown to be capable of accurately predicting adsorption for several metal ions and oxyanion selenite on a 62.9 m 2 /g SSA goethite served as the basis for the development of the adsorption modeling approach described in this paper. The predictive capability of the newly developed modeling approach was verified by comparing predictions of protons, SeO 3 2- , and Cd 2+ adsorption with experimental data from goethites with SSAs ranging between 21.3 and 105 m 2 /g; in total, 40 adsorption data sets from 13 different goethites were used for model verification. The results from this study indicate that the variation of surface reactivity of goethites can be successfully simulated by changing CFC, C 1 , and pK 2,singly (i.e. second protonation constant of singly-coordinated oxygens on the goethite surface) based on the SSA, which implies that self-consistent adsorption parameters can be applied to predict adsorption behavior over a range of goethite preparations.

58 GEOSCIENCES↗
DOE OSTI2025

Defect levels and self-compensation in iodine-doped CdTe single crystals

This study systematically documents defect levels in n-type iodine-doped cadmium telluride (CdTe:I) crystals as measured by thermoelectric effect spectroscopy, Hall-effect measurements, and photoluminescence and calculated by density functional theory. The primary donor, I Te , was identified with an activation energy of ∼0.05 eV (measured)/∼0.13 eV (calculated). Deep acceptor states, V Cd and I Te –V Cd complex, exhibited activation energies of ∼0.1 eV (measured)/∼0.19 eV (calculated) and ∼0.12 eV (measured)/∼0.24 eV (calculated), respectively. Self-compensation and Fermi level pinning were observed at ∼0.7 eV (measured)/∼1.08 eV (calculated), contributing to high resistivity in as-grown samples. Post-growth Cd annealing effectively removes compensation centers, releases iodine donors, and significantly reduces resistivity, resulting in an ideal n-type solar cell material.

Cd annealing↗
DOE OSTI2020

Materials Data on CdO2 by Materials Project

CdO2 crystallizes in the cubic Pa-3 space group. The structure is three-dimensional. Cd is bonded to six equivalent O atoms to form CdO6 octahedra that share corners with twelve equivalent CdO6 octahedra and corners with six equivalent OCd3O tetrahedra. The corner-sharing octahedral tilt angles are 71°. All Cd–O bond lengths are 2.35 Å. O is bonded to three equivalent Cd and one O atom to form OCd3O tetrahedra that share corners with three equivalent CdO6 octahedra and corners with fifteen equivalent OCd3O tetrahedra. The corner-sharing octahedral tilt angles are 70°. The O–O bond length is 1.50 Å.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on KCd3H8Cl7O4 by Materials Project

KCd3H6O3Cl7H2O crystallizes in the monoclinic P2_1/m space group. The structure is two-dimensional and consists of two water molecules and one KCd3H6O3Cl7 sheet oriented in the (0, 0, 1) direction. In the KCd3H6O3Cl7 sheet, K1+ is bonded in a 8-coordinate geometry to three O2- and five Cl1- atoms. There are one shorter (2.80 Å) and two longer (2.93 Å) K–O bond lengths. There are a spread of K–Cl bond distances ranging from 3.12–3.61 Å. There are two inequivalent Cd2+ sites. In the first Cd2+ site, Cd2+ is bonded to one O2- and five Cl1- atoms to form a mixture of corner and edge-sharing CdCl5O octahedra. The corner-sharing octahedral tilt angles are 37°. The Cd–O bond length is 2.38 Å. There are a spread of Cd–Cl bond distances ranging from 2.61–2.72 Å. In the second Cd2+ site, Cd2+ is bonded to six Cl1- atoms to form edge-sharing CdCl6 octahedra. There are two shorter (2.60 Å) and four longer (2.71 Å) Cd–Cl bond lengths. There are three inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the second H1+ site, H1+ is bonded in a 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. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a water-like geometry to one K1+ and two equivalent H1+ atoms. In the second O2- site, O2- is bonded in a distorted water-like geometry to one K1+, one Cd2+, and two H1+ atoms. There are four inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a 3-coordinate geometry to one K1+ and two Cd2+ atoms. In the second Cl1- site, Cl1- is bonded in a distorted trigonal non-coplanar geometry to one K1+ and two equivalent Cd2+ atoms. In the third Cl1- site, Cl1- is bonded in a distorted L-shaped geometry to one K1+ and two Cd2+ atoms. In the fourth Cl1- site, Cl1- is bonded in a distorted T-shaped geometry to three Cd2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba4Nd2Cd3Se10 by Materials Project

Ba4Nd2Cd3Se10 crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. there are four inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Ba–Se bond distances ranging from 3.31–3.78 Å. In the second Ba2+ site, Ba2+ is bonded to seven Se2- atoms to form distorted BaSe7 pentagonal bipyramids that share corners with two equivalent NdSe6 octahedra, corners with two equivalent BaSe7 pentagonal bipyramids, edges with three NdSe6 octahedra, edges with three equivalent BaSe7 pentagonal bipyramids, edges with four CdSe4 tetrahedra, and faces with two equivalent BaSe7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 17°. There are a spread of Ba–Se bond distances ranging from 3.29–3.45 Å. In the third Ba2+ site, Ba2+ is bonded to seven Se2- atoms to form distorted BaSe7 pentagonal bipyramids that share corners with two equivalent NdSe6 octahedra, corners with two equivalent BaSe7 pentagonal bipyramids, corners with five CdSe4 tetrahedra, corners with two equivalent CdSe4 trigonal pyramids, edges with three NdSe6 octahedra, edges with three equivalent BaSe7 pentagonal bipyramids, an edgeedge with one CdSe4 trigonal pyramid, and faces with two equivalent BaSe7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 22°. There are a spread of Ba–Se bond distances ranging from 3.30–3.51 Å. In the fourth Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight Se2- atoms. There are a spread of Ba–Se bond distances ranging from 3.28–3.71 Å. There are two inequivalent Nd3+ sites. In the first Nd3+ site, Nd3+ is bonded to six Se2- atoms to form NdSe6 octahedra that share corners with two equivalent BaSe7 pentagonal bipyramids, edges with two equivalent NdSe6 octahedra, edges with three BaSe7 pentagonal bipyramids, edges with two equivalent CdSe4 tetrahedra, and edges with two equivalent CdSe4 trigonal pyramids. There are a spread of Nd–Se bond distances ranging from 2.96–3.04 Å. In the second Nd3+ site, Nd3+ is bonded to six Se2- atoms to form NdSe6 octahedra that share corners with two equivalent BaSe7 pentagonal bipyramids, corners with three equivalent CdSe4 tetrahedra, edges with two equivalent NdSe6 octahedra, and edges with three BaSe7 pentagonal bipyramids. There are three shorter (2.97 Å) and three longer (3.00 Å) Nd–Se bond lengths. There are three inequivalent Cd2+ sites. In the first Cd2+ site, Cd2+ is bonded to four Se2- atoms to form CdSe4 tetrahedra that share corners with three equivalent NdSe6 octahedra, corners with two equivalent BaSe7 pentagonal bipyramids, corners with three CdSe4 tetrahedra, and edges with two equivalent BaSe7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 6–73°. There are a spread of Cd–Se bond distances ranging from 2.61–2.81 Å. In the second Cd2+ site, Cd2+ is bonded to four Se2- atoms to form distorted CdSe4 trigonal pyramids that share corners with two equivalent BaSe7 pentagonal bipyramids, corners with two equivalent CdSe4 trigonal pyramids, edges with two equivalent NdSe6 octahedra, and an edgeedge with one BaSe7 pentagonal bipyramid. There are a spread of Cd–Se bond distances ranging from 2.58–2.84 Å. In the third Cd2+ site, Cd2+ is bonded to four Se2- atoms to form CdSe4 tetrahedra that share corners with three equivalent BaSe7 pentagonal bipyramids, corners with three CdSe4 tetrahedra, edges with two equivalent NdSe6 octahedra, and edges with two equivalent BaSe7 pentagonal bipyramids. There are a spread of Cd–Se bond distances ranging from 2.67–2.78 Å. There are ten inequivalent Se2- sites. In the first Se2- site, Se2- is bonded to three Ba2+ and two equivalent Nd3+ atoms to form distorted SeBa3Nd2 trigonal bipyramids that share corners with six SeBa4Cd square pyramids, corners with two equivalent SeBa3Nd2 trigonal bipyramids, edges with two equivalent SeBa4NdCd octahedra, edges with two SeBa2NdCd2 square pyramids, and edges with three SeBa3Nd2 trigonal bipyramids. In the second Se2- site, Se2- is bonded to three Ba2+ and two equivalent Nd3+ atoms to form distorted SeBa3Nd2 trigonal bipyramids that share corners with four equivalent SeBa4Cd2 octahedra, corners with two equivalent SeBa2NdCd2 square pyramids, corners with two equivalent SeBa3Nd2 trigonal bipyramids, edges with five SeBa4Cd2 octahedra, an edgeedge with one SeBa2NdCd2 square pyramid, and edges with three SeBa3Nd2 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 40–50°. In the third Se2- site, Se2- is bonded to two equivalent Ba2+, one Nd3+, and two equivalent Cd2+ atoms to form distorted SeBa2NdCd2 square pyramids that share corners with two equivalent SeBa4Cd2 octahedra, corners with three SeBa2NdCd2 square pyramids, corners with two equivalent SeBa3Nd2 trigonal bipyramids, edges with two equivalent SeBa3Nd2Cd octahedra, edges with three SeBa2NdCd2 square pyramids, and an edgeedge with one SeBa3Nd2 trigonal bipyramid. The corner-sharing octahedral tilt angles are 60°. In the fourth Se2- site, Se2- is bonded to two equivalent Ba2+, one Nd3+, and two equivalent Cd2+ atoms to form distorted SeBa2NdCd2 square pyramids that share corners with two equivalent SeBa4Cd2 octahedra, corners with three SeBa2NdCd2 square pyramids, corners with two equivalent SeBa3Nd2 trigonal bipyramids, edges with three SeBa4Cd2 octahedra, edges with two equivalent SeBa2NdCd2 square pyramids, and an edgeedge with one SeBa3Nd2 trigonal bipyramid. The corner-sharing octahedral tilt angles are 53°. In the fifth Se2- site, Se2- is bonded in a distorted trigonal non-coplanar geometry to two Ba2+, one Nd3+, and two equivalent Cd2+ atoms. In the sixth Se2- site, Se2- is bonded to four Ba2+ and one Cd2+ atom to form distorted SeBa4Cd square pyramids that share corners with two equivalent SeBa4NdCd octahedra, corners with four SeBa2NdCd2 square pyramids, corners with four equivalent SeBa3Nd2 trigonal bipyramids, an edgeedge with one SeBa4NdCd octahedra, edges with three SeBa2NdCd2 square pyramids, and an edgeedge with one SeBa3Nd2 trigonal bipyramid. The corner-sharing octahedral tilt angles are 41°. In the seventh Se2- site, Se2- is bonded to four Ba2+ and two Cd2+ atoms to form distorted SeBa4Cd2 octahedra that share corners with six SeBa4NdCd octahedra, corners with four SeBa2NdCd2 square pyramids, corners with four equivalent SeBa3Nd2 trigonal bipyramids, edges with two equivalent SeBa4Cd2 octahedra, an edgeedge with one SeBa2NdCd2 square pyramid, an edgeedge with one SeBa3Nd2 trigonal bipyramid, and faces with two SeBa4NdCd octahedra. The corner-sharing octahedra tilt angles range from 41–58°. In the eighth Se2- site, Se2- is bonded to four Ba2+, one Nd3+, and one Cd2+ atom to form SeBa4NdCd octahedra that share corners with four SeBa4Cd2 octahedra, corners with two equivalent SeBa4Cd square pyramids, edges with three SeBa4NdCd octahedra, an edgeedge with one SeBa4Cd square pyramid, edges with four SeBa3Nd2 trigonal bipyramids, and a faceface with one SeBa4Cd2 octahedra. The corner-sharing octahedra tilt angles range from 22–53°. In the ninth Se2- site, Se2- is bonded in a 6-coordinate geometry to three Ba2+, two equivalent Nd3+, and one Cd2+ atom. In the tenth Se2- site, Se2- is bonded to three Ba2+, two equivalent Nd3+, and one Cd2+ atom to form distorted SeBa3Nd2Cd octahedra that share corners with six SeBa4Cd2 octahedra, edges with three SeBa4NdCd octahedra, edges with four SeBa2NdCd2 square pyramids, edges with two equivalent SeBa3Nd2 trigonal bipyramids, and a faceface with one SeBa4Cd2 octahedra. The corner-sharing octahedra tilt angles range from 22–58°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba4Sm2Cd3S10 by Materials Project

Ba4Sm2Cd3S10 crystallizes in the orthorhombic Cmc2_1 space group. The structure is three-dimensional. there are four inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Ba–S bond distances ranging from 3.17–3.68 Å. In the second Ba2+ site, Ba2+ is bonded to seven S2- atoms to form distorted BaS7 pentagonal bipyramids that share corners with two equivalent SmS6 octahedra, corners with two equivalent BaS7 pentagonal bipyramids, edges with three SmS6 octahedra, edges with three equivalent BaS7 pentagonal bipyramids, edges with two equivalent CdS4 tetrahedra, edges with two equivalent CdS4 trigonal pyramids, and faces with two equivalent BaS7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 16°. There are a spread of Ba–S bond distances ranging from 3.13–3.33 Å. In the third Ba2+ site, Ba2+ is bonded to seven S2- atoms to form distorted BaS7 pentagonal bipyramids that share corners with two equivalent SmS6 octahedra, corners with two equivalent BaS7 pentagonal bipyramids, corners with two equivalent CdS4 tetrahedra, corners with five CdS4 trigonal pyramids, edges with three SmS6 octahedra, edges with three equivalent BaS7 pentagonal bipyramids, an edgeedge with one CdS4 trigonal pyramid, and faces with two equivalent BaS7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 21°. There are a spread of Ba–S bond distances ranging from 3.18–3.38 Å. In the fourth Ba2+ site, Ba2+ is bonded in a 8-coordinate geometry to eight S2- atoms. There are a spread of Ba–S bond distances ranging from 3.15–3.59 Å. There are two inequivalent Sm3+ sites. In the first Sm3+ site, Sm3+ is bonded to six S2- atoms to form SmS6 octahedra that share corners with two equivalent BaS7 pentagonal bipyramids, edges with two equivalent SmS6 octahedra, edges with three BaS7 pentagonal bipyramids, and edges with four CdS4 trigonal pyramids. There are a spread of Sm–S bond distances ranging from 2.80–2.88 Å. In the second Sm3+ site, Sm3+ is bonded to six S2- atoms to form SmS6 octahedra that share corners with two equivalent BaS7 pentagonal bipyramids, corners with three equivalent CdS4 tetrahedra, edges with two equivalent SmS6 octahedra, and edges with three BaS7 pentagonal bipyramids. There are a spread of Sm–S bond distances ranging from 2.81–2.85 Å. There are three inequivalent Cd2+ sites. In the first Cd2+ site, Cd2+ is bonded to four S2- atoms to form CdS4 tetrahedra that share corners with three equivalent SmS6 octahedra, corners with two equivalent BaS7 pentagonal bipyramids, corners with two equivalent CdS4 tetrahedra, a cornercorner with one CdS4 trigonal pyramid, and edges with two equivalent BaS7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 5–72°. There are a spread of Cd–S bond distances ranging from 2.49–2.71 Å. In the second Cd2+ site, Cd2+ is bonded to four S2- atoms to form distorted CdS4 trigonal pyramids that share corners with two equivalent BaS7 pentagonal bipyramids, corners with two equivalent CdS4 trigonal pyramids, edges with two equivalent SmS6 octahedra, and an edgeedge with one BaS7 pentagonal bipyramid. There are a spread of Cd–S bond distances ranging from 2.46–2.74 Å. In the third Cd2+ site, Cd2+ is bonded to four S2- atoms to form distorted CdS4 trigonal pyramids that share corners with three equivalent BaS7 pentagonal bipyramids, a cornercorner with one CdS4 tetrahedra, corners with two equivalent CdS4 trigonal pyramids, edges with two equivalent SmS6 octahedra, and edges with two equivalent BaS7 pentagonal bipyramids. There are a spread of Cd–S bond distances ranging from 2.55–2.70 Å. There are ten inequivalent S2- sites. In the first S2- site, S2- is bonded to three Ba2+ and two equivalent Sm3+ atoms to form distorted SBa3Sm2 trigonal bipyramids that share corners with six SBa4Cd square pyramids, edges with two equivalent SBa4SmCd octahedra, edges with two SBa3Sm2 square pyramids, and edges with two equivalent SBa3Sm2 trigonal bipyramids. In the second S2- site, S2- is bonded to three Ba2+ and two equivalent Sm3+ atoms to form distorted SBa3Sm2 square pyramids that share corners with four equivalent SBa4Cd2 octahedra, corners with two equivalent SBa2SmCd2 square pyramids, corners with two equivalent SBa3Sm2 trigonal bipyramids, edges with five SBa4Cd2 octahedra, edges with three SBa3Sm2 square pyramids, and an edgeedge with one SBa3Sm2 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 40–51°. In the third S2- site, S2- is bonded in a 5-coordinate geometry to two equivalent Ba2+, one Sm3+, and two equivalent Cd2+ atoms. In the fourth S2- site, S2- is bonded to two equivalent Ba2+, one Sm3+, and two equivalent Cd2+ atoms to form distorted SBa2SmCd2 square pyramids that share corners with two equivalent SBa4Cd2 octahedra, corners with four SBa3Sm2 square pyramids, edges with three SBa4Cd2 octahedra, and edges with three SBa3Sm2 square pyramids. The corner-sharing octahedral tilt angles are 54°. In the fifth S2- site, S2- is bonded in a distorted trigonal non-coplanar geometry to two Ba2+, one Sm3+, and two equivalent Cd2+ atoms. In the sixth S2- site, S2- is bonded to four Ba2+ and one Cd2+ atom to form distorted SBa4Cd square pyramids that share corners with two equivalent SBa4SmCd octahedra, corners with two equivalent SBa2SmCd2 square pyramids, corners with four equivalent SBa3Sm2 trigonal bipyramids, an edgeedge with one SBa4SmCd octahedra, edges with two equivalent SBa4Cd square pyramids, and an edgeedge with one SBa3Sm2 trigonal bipyramid. The corner-sharing octahedral tilt angles are 40°. In the seventh S2- site, S2- is bonded to four Ba2+ and two Cd2+ atoms to form distorted SBa4Cd2 octahedra that share corners with six SBa4SmCd octahedra, corners with six SBa3Sm2 square pyramids, edges with two equivalent SBa4Cd2 octahedra, edges with two SBa2SmCd2 square pyramids, and faces with two SBa4SmCd octahedra. The corner-sharing octahedra tilt angles range from 41–58°. In the eighth S2- site, S2- is bonded to four Ba2+, one Sm3+, and one Cd2+ atom to form SBa4SmCd octahedra that share corners with four SBa4Cd2 octahedra, corners with two equivalent SBa4Cd square pyramids, edges with three SBa4SmCd octahedra, edges with three SBa3Sm2 square pyramids, edges with two equivalent SBa3Sm2 trigonal bipyramids, and a faceface with one SBa4Cd2 octahedra. The corner-sharing octahedra tilt angles range from 21–54°. In the ninth S2- site, S2- is bonded in a 6-coordinate geometry to three Ba2+, two equivalent Sm3+, and one Cd2+ atom. In the tenth S2- site, S2- is bonded to three Ba2+, two equivalent Sm3+, and one Cd2+ atom to form SBa3Sm2Cd octahedra that share corners with six SBa4Cd2 octahedra, edges with three SBa4SmCd octahedra, edges with four SBa3Sm2 square pyramids, and a faceface with one SBa4Cd2 octahedra. The corner-sharing octahedra tilt angles range from 21–58°.

36 MATERIALS SCIENCE↗