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All sourcesNASA NTRSDOE OSTI
NASA NTRS1998

Potential Mars Surveyor 2001 Landing Sites: Low-Elevation Cratered "Highlands" in Central and Eastern Sinus Meridiani and Near Amenthes Fossae

The main scientific goal for the Mars Surveyor Program 2001 (MSP 01) landed mission is to collect and characterize 91 rock and 13 soil core samples using an integrated instrument suite onboard the Athena Rover. If possible, these samples will be retrieved and returned to Earth via a MSP 05 or MSP 07 mission. Preliminary engineering constraints for the MSP 01 landing site call for a location that lies between 15 S and 30 N, and below about 2 km elevation (based on Viking-era topography). Desirable landing sites for MSP 01 are to be located "in the ancient highlands where the environmental conditions may have been favorable to the preservation of evidence of possible prebiotic or biotic processes including the emergence (and, potentially, the persistence) of life". We interpret this to mean that the desirable sites include those that have evidence of aqueous sediments that might have been deposited during the Noachian and/or Hesperian Epochs of Mars' history. In addition to the search for subaqueous sedimentary deposits, we took into consideration the fact that the rover, Athena, will need to be able to access these materials. Thus, a site where aeolian deflation has occurred might be desirable because it might expose, in situ, layered sedimentary deposits. Deflated areas, of course, might include potential landing hazards in the form of meterscale buttes and mesas (e.g., Christmas Lake Valley, OR), thus careful study of such sites with high resolution images will be required before a decision is made to land. We have been examining three regions that have potential to be considered for MSP 01 landing sites. This work is based on Viking (VIS, IRTM) and Phobos 2 (Termoskan) observations and should be regarded as preliminary because we believe that the final site selection should also be based upon analysis of Mars Global Surveyor observations that help constrain mineralogy (TES) and local geomorphology (MOC, MOLA). (1) Eastern Sinus Meridiani Region (proposed by K. S. Edgett) Sinus Meridiani is a persistent low-albedo (< 0. 16) region on the martian equator that has been recognized for about 400 years. All of Sinus Meridiani is below the 2 km elevation constraint for MSP 01. The region includes cratered highlands, valley networks, aeolian dunes, and possible aqueous sedimentary deposits. The landing site study region is located in the eastern portion of Sinus Meridiani. It is bounded by latitudes 10 S to 2 N, longitudes 355 W to 345 W, and the elevations are mostly 1-2 km. The center of this area contains a medium-albedo (0.19-0.21), relatively smooth-surfaced deposit that was suggested by Rice to be a lacustrine deposit. Several potential landing areas can be suggested within this region. Based on Viking and Phobos 2 data, the favored sites so far are centered at 7.6 S, 346.9 W and 0.8 S, 349 W. Thermal inertias are 3.2-7.0 x 10(exp -3) cal /sq cm s(exp -0.5)/K; and rock abundances are around 2-6%. The site at 7.6 S, 346.9 W is at the southern end of the smooth, medium-albedo unit that might have a lacustrine origin. At this location, numerous channels appear to have drained toward the smooth unit. Viking images from orbit 747A show this area at about 15 m/pixel ground resolution. The images reveal that aeolian deflation has occurred along the deposit's margins. Bright (i.e., albedo >= 0.21) aeolian dunes are present on the channel floors and in some of the depressions on the smooth unit. The bright, apparently active dunes might consist of material (perhaps lakedeposited sands) that has been eroded from the smooth unit. The site at approximately 0.8 S, 349 W is selected because it offers an opportunity to solve a long-standing puzzle about Mars remote sensing. There are three main "color" units on Mars: "dark red, dark gray, and bright red". This landing site would allow the Athena rover an opportunity to investigate all three materials within close proximity (the best place on Mars to do so). There are no high resolution (better than 100 m/pixel) Viking or Mariner images of this site. (2) Central Sinus Meridiani Region (proposed by K. S. Edgett and T. J. Parker) Central Sinus Meridiani is characterized by two types of surfaces [4]. One is like typical martian cratered highlands elsewhere- there are old valley networks and old impact craters. The other is relatively smooth and flat. These two units are in contact around 3.1 S between 5 W and 4 E longitudes. Valley networks- including one at 6'S, 358 W that rivals the Grand Canyon of Arizona- once drained toward the smooth unit. Edgett and Parker [4] proposed that the smooth unit might consist of sediments laid down in a large Noachian-aged sea/ocean that would have covered much of the northern hemisphere. Schultz and Lutz [I I I suggested that it is a paleopolar layered deposit. Regardless, the smooth unit where it contacts the cratered terrain would make an excellent site for Athena rover to investigate. The site is best seen in Viking high resolution images from orbits 408B (about 30 m/pixel) and 746A (about 12 m/pixel). These images suggest that aeolian deflation has occurred along the margin of the smooth unit, and this deflation has exposed horizontal larrs of material. The elevation is about 0.5 km; thermal inertias are 6.5-8.0 x 10(exp -3) cal /sq cm s(exp -0.5) / K; rock abundances are 2-4%; and the surface is probably sandy with dark drifts and ripples but almost no actual dunes. We suggest a landing around 3.2 S, 3.0 W would test the aqueous sediment hypothesis and provide a potentially smooth surface on which to land. (3) Amenthes Fossae Region (proposed by S. N. Huntwork and K. S. Edgett) The Amenthes Fossae are a series of graben/fissures that are circumferential to the southeast side of Isidis Planitia. These fissures cross a variety of ancient, heavily cratered Noachian terrain and younger, Hesperian and Amazonian terrain. We focused our search on a region 0-15 N, 250 - 270 W. Elevations are -0.5 to 2 km. Depending upon whether Isidis Planitia was ever a water-rich environment, this region might have been influenced by aqueous sedimentation. Valley networks are common, and they drained toward the north and northwest. We focused our work on a set of Viking orbiter high-resolution images, 719A 1-48. These have resolutions 16-24 rri/pixel. We examined images 20-23, centered at 2 N, 258 W. This site, on the plains just southwest of a 42 km-diameter crater, includes a valley network channel, a relatively young crater ejecta deposit, a few buttes composed of presumably ancient, Noachian bedrock, and a "plains" unit. The plains might make an ideal landing surface, except for the presence of some fine-scale ridges (oriented approximately N-S). The ridges are probably yardangs, thus this site offers a place where aeolian deflation has probably exposed some of the layered rock units that comprise the "plains". Thermal inertias are 7.9-8.3 x 10(exp -3) cal/sq cm s(exp -0.5) /K and rock abundances are 10-15%. A rover traverse might include the opportunity to go down to the floor (and sample along the walls) of the valley network channel at 2 N 258.1 W.

Edgett, K. S.↗
NASA NTRS2020

Modeling Whitecaps on Global Scale

Whitecaps play an important role in the surface-atmosphere interactions across the ocean. They are directly linked to the energy dissipation rate during wave breaking and transfer of heat, momentum, and gas/aerosol exchange from the wind to the sea surface. Although the first models of W were dependent only on wind speeds, a large number of diverse models based on wind and sea state which include wave height, wave age, friction velocity, and stability effects have been proposed since then. However, it is recognized that most of the proposed W models have strong systematic (e.g., zonal bias) and random errors when compared against observations. This is partly due to the differences in environmental conditions, measurement techniques, and geographical locations among these studies. But, some of these biases are linked to the inability of the proposed models to capture the variability in W in certain wind/wave regimes. Despite the knowledge of existing biases, W residual relationships from the models with wind and wave fields remain highly uncertain, with residual trends varying between the published studies. Here, we take advantage of the availability of relatively dense observations of W from WindSat microwave satellite retrievals in combination with the University of Miami wave model which was recently incorporated within the NASA GMAO/GEOS system (GEOS-UMWM). We use Windsat W retrievals to assess and constrain the previously published W models and understand the relationships of residuals from models in different wind/wave regimes. We link these unexplained residual variations to additional factors such as swell index, drag coefficient etc and add information to the existing whitecap models. Since Windsat retrievals cover wide range of environmental conditions, it helps to reduce the uncertainties associated with differences in measurement techniques. Regression of wind-wave fields against all Windsat data points (CTL) results in larger residuals for lower wave age and W is overestimated upto ~4% for wave age < 10 and underestimated by upto ~2% as wave age increases. We attest to this bias by considering two approaches. One is to perform regression separately for different stages of wave development such as developing sea, fully developed, and wind sea regimes thereby understanding the sensitivity of regression coefficients to sea state (EXP1). Another is to derive coefficients of W models in EXP1 as a function of additional wind/wave factors such as swell index, drag coefficient, and mean squared slope, deriving more nonlinear W models (EXP2). EXP2 provides reduction in Root Mean Squared Error (RMSE) by 0.1-0.3%. Sea surface drag has a stronger relationship with regression coefficients compared to swell index.These additional factors provide improved parameterizations in different wind and wave age regimes, with smaller unexplained/residual variations in W that has been a major concern in the W community.

Raman, Aishwarya↗
DOE OSTI2026

Constraints on Dynamical Dark Energy from Multiple Probes in the Full Dark Energy Survey

We present results on dark energy evolution, assuming a time-dependent equation of state $w(a)=w_0+w_a(1-a)$, from growth and geometric probes using the full six-year Dark Energy Survey dataset: type Ia supernovae, baryon acoustic oscillations, and weak gravitational lensing and galaxy clustering (3$\times$2pt). The combination yields $w_0=-0.84^{+0.10}_{-0.10}$ and $w_a=-0.44^{+0.60}_{-0.55}$, the tightest constraints ever obtained from a single survey, with $2.2σ$ deviation from a cosmological constant. Adding the DESI DR2 BAO data yields $w_0=-0.84^{+0.06}_{-0.07}$ and $w_a=-0.53^{+0.33}_{-0.28}$, representing the most stringent low-redshift-only test of dynamical dark energy to date, with a $2.3σ$ deviation. In this combination, adding 3$\times$2pt doubles the constraining power. Finally, when combined with primary CMB information, we obtain $w_0=-0.82^{+0.05}_{-0.05}$, $w_a=-0.63^{+0.21}_{-0.18}$, with a $3.0σ$ deviation. We find that including 3$\times$2pt in the previously studied SN + DESI BAO + CMB combination leaves the significance essentially unchanged ($3.2 σ$ to $3.0σ$) while improving the figure of merit by $\sim$10%. We systematically investigate the impact of leaving out each one of the probes and find that the significance of the deviation from a cosmological constant ranges from 2.3 to 3.2$σ$, with best-fit parameters consistently in the region $w_0 >-1$ and $w_a <0$. Excluding SN from the all data combination yields a $2.6σ$ departure from $Λ$CDM, providing a cross-check independent of supernova photometric calibration. These results support the weak preference for evolving dark energy reported by several recent cosmological analyses. By combining growth and geometric probes from a single survey, this work realizes the multi-probe dark energy program envisioned at the inception of DES.

Abbott, T. M.C. [Cerro-Tololo InterAmerican Obs.] ↗
DOE OSTI2026

Analysis and modeling of tungsten emission and net erosion in the DIII-D divertor using updated atomic data

Tungsten (W) is one of the leading candidate materials for plasma-facing components. However, its main drawback is its high radiative efficiency; if W penetrates the plasma, it can lead to core degradation or even collapse. Since eroded tungsten tends to ionize in the sheath and redeposit promptly, the net erosion flux that escapes prompt redeposition can differ significantly from the gross erosion. This work presents a modeling framework to estimate net erosion and photon emission from W coatings exposed to the lower divertor of DIII-D using the DiMES material exposure probe. The approach couples RustBCA for sputtering yields with a Monte Carlo transport code (LPTMC) that models redeposition and W emission. Computation is carried out with new atomic data, based on R-matrix and Mons calculations, leading to lower ionization probabilities and a twofold increase in net erosion estimates compared to calculations done with OPEN-ADAS atomic data. The model results are benchmarked against experimental measurements, showing quantitative agreement for erosion, although the trends in W emission are reproduced only qualitatively. The model is also used to assess whether W II emission can serve as a direct measurement of the net erosion of W in the lower divertor of DIII-D. Simulations show that this is not valid if the electron pressure is above ~120 Pa or if the toroidal length of the eroded material is smaller than the parallel-to-B distance traveled by impurity ions before steady-state conditions are reached. Finally, simulations suggest that when W is sputtered by carbon ions with high impact energies (≳300 eV) in DIII-D, W net erosion scales with W gross erosion and can be numerically approximated using W I flux alone as input.

70 PLASMA PHYSICS AND FUSION TECHNOLOGY↗
DOE OSTI2020

Materials Data on W3O8 by Materials Project

W3O8 crystallizes in the orthorhombic Cmmm space group. The structure is three-dimensional. there are two inequivalent W+5.33+ sites. In the first W+5.33+ site, W+5.33+ is bonded to seven O2- atoms to form WO7 pentagonal bipyramids that share corners with two equivalent WO6 octahedra, corners with three equivalent WO7 pentagonal bipyramids, an edgeedge with one WO6 octahedra, and edges with two equivalent WO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 44°. There are a spread of W–O bond distances ranging from 1.93–2.13 Å. In the second W+5.33+ site, W+5.33+ is bonded to six O2- atoms to form WO6 octahedra that share corners with two equivalent WO6 octahedra, corners with four equivalent WO7 pentagonal bipyramids, and edges with two equivalent WO7 pentagonal bipyramids. The corner-sharing octahedral tilt angles are 0°. There is two shorter (1.93 Å) and four longer (2.02 Å) W–O bond length. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted trigonal planar geometry to three W+5.33+ atoms. In the second O2- site, O2- is bonded in a linear geometry to two equivalent W+5.33+ atoms. In the third O2- site, O2- is bonded in a linear geometry to two equivalent W+5.33+ atoms. In the fourth O2- site, O2- is bonded in a linear geometry to two equivalent W+5.33+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on K4W11O35 by Materials Project

K4W11O35 crystallizes in the triclinic P1 space group. The structure is three-dimensional. there are four inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 9-coordinate geometry to nine O2- atoms. There are a spread of K–O bond distances ranging from 2.66–3.43 Å. In the second K1+ site, K1+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of K–O bond distances ranging from 2.71–3.35 Å. In the third K1+ site, K1+ is bonded in a 7-coordinate geometry to seven O2- atoms. There are a spread of K–O bond distances ranging from 2.75–3.11 Å. In the fourth K1+ site, K1+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of K–O bond distances ranging from 2.69–3.09 Å. There are eleven inequivalent W6+ sites. In the first W6+ site, W6+ is bonded to five O2- atoms to form corner-sharing WO5 trigonal bipyramids. The corner-sharing octahedra tilt angles range from 36–40°. There are a spread of W–O bond distances ranging from 1.77–2.23 Å. In the second W6+ site, W6+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There are a spread of W–O bond distances ranging from 1.89–1.98 Å. In the third W6+ site, W6+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of W–O bond distances ranging from 1.76–2.25 Å. In the fourth W6+ site, W6+ is bonded to four O2- atoms to form corner-sharing WO4 tetrahedra. The corner-sharing octahedral tilt angles are 31°. There are a spread of W–O bond distances ranging from 1.76–1.88 Å. In the fifth W6+ site, W6+ is bonded to six O2- atoms to form distorted WO6 octahedra that share a cornercorner with one WO6 octahedra and corners with two equivalent WO5 trigonal bipyramids. The corner-sharing octahedral tilt angles are 4°. There are a spread of W–O bond distances ranging from 1.77–2.25 Å. In the sixth W6+ site, W6+ is bonded to six O2- atoms to form WO6 octahedra that share a cornercorner with one WO6 octahedra, corners with two equivalent WO7 pentagonal bipyramids, and a cornercorner with one WO4 tetrahedra. The corner-sharing octahedral tilt angles are 4°. There are a spread of W–O bond distances ranging from 1.89–2.11 Å. In the seventh W6+ site, W6+ is bonded to five O2- atoms to form corner-sharing WO5 trigonal bipyramids. There are a spread of W–O bond distances ranging from 1.76–1.94 Å. In the eighth W6+ site, W6+ is bonded to seven O2- atoms to form corner-sharing WO7 pentagonal bipyramids. The corner-sharing octahedra tilt angles range from 31–32°. There are a spread of W–O bond distances ranging from 1.99–2.17 Å. In the ninth W6+ site, W6+ is bonded to five O2- atoms to form corner-sharing WO5 trigonal bipyramids. There are a spread of W–O bond distances ranging from 1.85–2.15 Å. In the tenth W6+ site, W6+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of W–O bond distances ranging from 1.76–2.41 Å. In the eleventh W6+ site, W6+ is bonded in a distorted pentagonal planar geometry to five O2- atoms. There are a spread of W–O bond distances ranging from 1.86–2.17 Å. There are thirty-five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to two W6+ atoms. In the second O2- site, O2- is bonded in a distorted single-bond geometry to two K1+ and one W6+ atom. In the third O2- site, O2- is bonded in a 1-coordinate geometry to one K1+ and two W6+ atoms. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to one K1+ and two W6+ atoms. In the fifth O2- site, O2- is bonded in a distorted water-like geometry to one K1+ and one W6+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W6+ atoms. In the seventh O2- site, O2- is bonded in a 3-coordinate geometry to one K1+ and two W6+ atoms. In the eighth O2- site, O2- is bonded in a bent 120 degrees geometry to one K1+ and one W6+ atom. In the ninth O2- site, O2- is bonded in a 3-coordinate geometry to one K1+ and two W6+ atoms. In the tenth O2- site, O2- is bonded in a distorted single-bond geometry to one K1+ and two W6+ atoms. In the eleventh O2- site, O2- is bonded in a water-like geometry to two W6+ atoms. In the twelfth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W6+ atoms. In the thirteenth O2- site, O2- is bonded in a bent 150 degrees geometry to two W6+ atoms. In the fourteenth O2- site, O2- is bonded in a single-bond geometry to one W6+ atom. In the fifteenth O2- site, O2- is bonded in a linear geometry to one K1+ and two W6+ atoms. In the sixteenth O2- site, O2- is bonded in a bent 150 degrees geometry to two W6+ atoms. In the seventeenth O2- site, O2- is bonded in a distorted single-bond geometry to two K1+ and one W6+ atom. In the eighteenth O2- site, O2- is bonded in a bent 150 degrees geometry to one K1+ and two W6+ atoms. In the nineteenth O2- site, O2- is bonded in a 3-coordinate geometry to one K1+ and two W6+ atoms. In the twentieth O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, one W6+, and one O2- atom. The O–O bond length is 1.50 Å. In the twenty-first O2- site, O2- is bonded in a 4-coordinate geometry to one K1+, two W6+, and one O2- atom. The O–O bond length is 1.49 Å. In the twenty-second O2- site, O2- is bonded in a 3-coordinate geometry to two W6+ and one O2- atom. In the twenty-third O2- site, O2- is bonded in a 3-coordinate geometry to two K1+, one W6+, and one O2- atom. In the twenty-fourth O2- site, O2- is bonded in a 2-coordinate geometry to one K1+ and two W6+ atoms. In the twenty-fifth O2- site, O2- is bonded in a 2-coordinate geometry to one K1+ and two W6+ atoms. In the twenty-sixth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and two W6+ atoms. In the twenty-seventh O2- site, O2- is bonded in a bent 150 degrees geometry to two W6+ atoms. In the twenty-eighth O2- site, O2- is bonded in a 1-coordinate geometry to one W6+ and one O2- atom. The O–O bond length is 1.46 Å. In the twenty-ninth O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, one W6+, and one O2- atom. In the thirtieth O2- site, O2- is bonded in a 3-coordinate geometry to one K1+, one W6+, and one O2- atom. The O–O bond length is 1.50 Å. In the thirty-first O2- site, O2- is bonded in a 4-coordinate geometry to one K1+, two W6+, and one O2- atom. In the thirty-second O2- site, O2- is bonded in a single-bond geometry to one W6+ atom. In the thirty-third O2- site, O2- is bonded in a linear geometry to two W6+ atoms. In the thirty-fourth O2- site, O2- is bonded in a bent 150 degrees geometry to two K1+ and two W6+ atoms. In the thirty-fifth O2- site, O2- is bonded in a 2-coordinate geometry to one K1+ and two W6+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba(WO3)6 by Materials Project

Ba(WO3)6 crystallizes in the trigonal P31m space group. The structure is three-dimensional. Ba2+ is bonded in a 6-coordinate geometry to six equivalent O2- atoms. All Ba–O bond lengths are 3.04 Å. There are two inequivalent W+5.67+ sites. In the first W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 0–32°. There are a spread of W–O bond distances ranging from 1.93–1.96 Å. In the second W+5.67+ site, W+5.67+ is bonded to six O2- atoms to form corner-sharing WO6 octahedra. The corner-sharing octahedra tilt angles range from 0–30°. There are a spread of W–O bond distances ranging from 1.93–1.96 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a linear geometry to two W+5.67+ atoms. In the second O2- site, O2- is bonded in a linear geometry to two W+5.67+ atoms. In the third O2- site, O2- is bonded in a bent 150 degrees geometry to two equivalent W+5.67+ atoms. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ba2+ and two equivalent W+5.67+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PrW3 by Materials Project

PrW3 is alpha bismuth trifluoride structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional. Pr is bonded in a distorted body-centered cubic geometry to fourteen W atoms. There are eight shorter (2.90 Å) and six longer (3.35 Å) Pr–W bond lengths. There are two inequivalent W sites. In the first W site, W is bonded to four equivalent Pr and four equivalent W atoms to form a mixture of distorted corner, edge, and face-sharing WPr4W4 tetrahedra. All W–W bond lengths are 2.90 Å. In the second W site, W is bonded in a 8-coordinate geometry to six equivalent Pr and eight equivalent W atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Yb3W by Materials Project

Yb3W is alpha bismuth trifluoride structured and crystallizes in the tetragonal I4/mmm space group. The structure is three-dimensional. there are three inequivalent Yb sites. In the first Yb site, Yb is bonded to four Yb and four W atoms to form a mixture of distorted edge, corner, and face-sharing YbYb4W4 tetrahedra. All Yb–Yb bond lengths are 3.25 Å. All Yb–W bond lengths are 3.25 Å. In the second Yb site, Yb is bonded in a 12-coordinate geometry to eight equivalent Yb and six W atoms. There are four shorter (3.74 Å) and two longer (3.77 Å) Yb–W bond lengths. In the third Yb site, Yb is bonded in a 12-coordinate geometry to eight equivalent Yb and six W atoms. There are four shorter (3.74 Å) and two longer (3.77 Å) Yb–W bond lengths. There are two inequivalent W sites. In the first W site, W is bonded in a distorted body-centered cubic geometry to fourteen Yb atoms. In the second W site, W is bonded in a distorted body-centered cubic geometry to fourteen Yb atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Te2MoW3(SeS2)2 by Materials Project

WTe2WSe2WS2MoS2 is Molybdenite-derived structured and crystallizes in the trigonal P3m1 space group. The structure is two-dimensional and consists of one MoS2 sheet oriented in the (0, 0, 1) direction; one WS2 sheet oriented in the (0, 0, 1) direction; one WSe2 sheet oriented in the (0, 0, 1) direction; and one WTe2 sheet oriented in the (0, 0, 1) direction. In the MoS2 sheet, Mo6+ is bonded to six S2- atoms to form distorted edge-sharing MoS6 pentagonal pyramids. There are three shorter (2.44 Å) and three longer (2.45 Å) Mo–S bond lengths. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted T-shaped geometry to three equivalent Mo6+ atoms. In the second S2- site, S2- is bonded in a 3-coordinate geometry to three equivalent Mo6+ atoms. In the WS2 sheet, W+3.33+ is bonded to six S2- atoms to form distorted edge-sharing WS6 pentagonal pyramids. All W–S bond lengths are 2.45 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted T-shaped geometry to three equivalent W+3.33+ atoms. In the second S2- site, S2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms. In the WSe2 sheet, W+3.33+ is bonded to six equivalent Se2- atoms to form distorted edge-sharing WSe6 pentagonal pyramids. All W–Se bond lengths are 2.55 Å. Se2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms. In the WTe2 sheet, W+3.33+ is bonded to six Te2- atoms to form distorted edge-sharing WTe6 pentagonal pyramids. All W–Te bond lengths are 2.71 Å. There are two inequivalent Te2- sites. In the first Te2- site, Te2- is bonded in a 12-coordinate geometry to three equivalent W+3.33+ atoms. In the second Te2- site, Te2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Te2MoW3(SeS2)2 by Materials Project

WTe2WSe2WS2MoS2 is Molybdenite-derived structured and crystallizes in the trigonal P3m1 space group. The structure is two-dimensional and consists of one MoS2 sheet oriented in the (0, 0, 1) direction; one WS2 sheet oriented in the (0, 0, 1) direction; one WSe2 sheet oriented in the (0, 0, 1) direction; and one WTe2 sheet oriented in the (0, 0, 1) direction. In the MoS2 sheet, Mo6+ is bonded to six S2- atoms to form distorted edge-sharing MoS6 pentagonal pyramids. All Mo–S bond lengths are 2.45 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted T-shaped geometry to three equivalent Mo6+ atoms. In the second S2- site, S2- is bonded in a 3-coordinate geometry to three equivalent Mo6+ atoms. In the WS2 sheet, W+3.33+ is bonded to six S2- atoms to form distorted edge-sharing WS6 pentagonal pyramids. All W–S bond lengths are 2.45 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted T-shaped geometry to three equivalent W+3.33+ atoms. In the second S2- site, S2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms. In the WSe2 sheet, W+3.33+ is bonded to six equivalent Se2- atoms to form distorted edge-sharing WSe6 pentagonal pyramids. All W–Se bond lengths are 2.55 Å. Se2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms. In the WTe2 sheet, W+3.33+ is bonded to six Te2- atoms to form distorted edge-sharing WTe6 pentagonal pyramids. All W–Te bond lengths are 2.71 Å. There are two inequivalent Te2- sites. In the first Te2- site, Te2- is bonded in a 12-coordinate geometry to three equivalent W+3.33+ atoms. In the second Te2- site, Te2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Te2MoW3(SeS2)2 by Materials Project

WTe2WSe2WS2MoS2 is Molybdenite-derived structured and crystallizes in the trigonal P3m1 space group. The structure is two-dimensional and consists of one MoS2 sheet oriented in the (0, 0, 1) direction; one WS2 sheet oriented in the (0, 0, 1) direction; one WSe2 sheet oriented in the (0, 0, 1) direction; and one WTe2 sheet oriented in the (0, 0, 1) direction. In the MoS2 sheet, Mo6+ is bonded to six equivalent S2- atoms to form distorted edge-sharing MoS6 pentagonal pyramids. All Mo–S bond lengths are 2.45 Å. S2- is bonded in a 3-coordinate geometry to three equivalent Mo6+ atoms. In the WS2 sheet, W+3.33+ is bonded to six S2- atoms to form distorted edge-sharing WS6 pentagonal pyramids. All W–S bond lengths are 2.45 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted T-shaped geometry to three equivalent W+3.33+ atoms. In the second S2- site, S2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms. In the WSe2 sheet, W+3.33+ is bonded to six equivalent Se2- atoms to form distorted edge-sharing WSe6 pentagonal pyramids. All W–Se bond lengths are 2.55 Å. Se2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms. In the WTe2 sheet, W+3.33+ is bonded to six Te2- atoms to form distorted edge-sharing WTe6 pentagonal pyramids. All W–Te bond lengths are 2.71 Å. There are two inequivalent Te2- sites. In the first Te2- site, Te2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms. In the second Te2- site, Te2- is bonded in a 12-coordinate geometry to three equivalent W+3.33+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Te2MoW3(Se2S)2 by Materials Project

WTe2WSe2MoSe2WS2 is Molybdenite-derived structured and crystallizes in the trigonal P3m1 space group. The structure is two-dimensional and consists of one MoSe2 sheet oriented in the (0, 0, 1) direction; one WS2 sheet oriented in the (0, 0, 1) direction; one WSe2 sheet oriented in the (0, 0, 1) direction; and one WTe2 sheet oriented in the (0, 0, 1) direction. In the MoSe2 sheet, Mo6+ is bonded to six equivalent Se2- atoms to form distorted edge-sharing MoSe6 pentagonal pyramids. All Mo–Se bond lengths are 2.55 Å. Se2- is bonded in a 3-coordinate geometry to three equivalent Mo6+ atoms. In the WS2 sheet, W+3.33+ is bonded to six S2- atoms to form distorted edge-sharing WS6 pentagonal pyramids. All W–S bond lengths are 2.46 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms. In the second S2- site, S2- is bonded in a distorted T-shaped geometry to three equivalent W+3.33+ atoms. In the WSe2 sheet, W+3.33+ is bonded to six equivalent Se2- atoms to form distorted edge-sharing WSe6 pentagonal pyramids. All W–Se bond lengths are 2.55 Å. Se2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms. In the WTe2 sheet, W+3.33+ is bonded to six Te2- atoms to form distorted edge-sharing WTe6 pentagonal pyramids. All W–Te bond lengths are 2.71 Å. There are two inequivalent Te2- sites. In the first Te2- site, Te2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms. In the second Te2- site, Te2- is bonded in a 12-coordinate geometry to three equivalent W+3.33+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Te4MoW3(SeS)2 by Materials Project

WTe2MoTe2WSe2WS2 is Molybdenite-derived structured and crystallizes in the trigonal P3m1 space group. The structure is two-dimensional and consists of one MoTe2 sheet oriented in the (0, 0, 1) direction; one WS2 sheet oriented in the (0, 0, 1) direction; one WSe2 sheet oriented in the (0, 0, 1) direction; and one WTe2 sheet oriented in the (0, 0, 1) direction. In the MoTe2 sheet, Mo6+ is bonded to six equivalent Te2- atoms to form distorted edge-sharing MoTe6 pentagonal pyramids. All Mo–Te bond lengths are 2.71 Å. Te2- is bonded in a 12-coordinate geometry to three equivalent Mo6+ atoms. In the WS2 sheet, W+3.33+ is bonded to six S2- atoms to form distorted edge-sharing WS6 pentagonal pyramids. All W–S bond lengths are 2.47 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted T-shaped geometry to three equivalent W+3.33+ atoms. In the second S2- site, S2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms. In the WSe2 sheet, W+3.33+ is bonded to six equivalent Se2- atoms to form distorted edge-sharing WSe6 pentagonal pyramids. All W–Se bond lengths are 2.57 Å. Se2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms. In the WTe2 sheet, W+3.33+ is bonded to six Te2- atoms to form distorted edge-sharing WTe6 pentagonal pyramids. All W–Te bond lengths are 2.72 Å. There are two inequivalent Te2- sites. In the first Te2- site, Te2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms. In the second Te2- site, Te2- is bonded in a 12-coordinate geometry to three equivalent W+3.33+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Te4MoW3(SeS)2 by Materials Project

WTe2MoTe2WSe2WS2 is Molybdenite-derived structured and crystallizes in the trigonal P3m1 space group. The structure is two-dimensional and consists of one MoTe2 sheet oriented in the (0, 0, 1) direction; one WS2 sheet oriented in the (0, 0, 1) direction; one WSe2 sheet oriented in the (0, 0, 1) direction; and one WTe2 sheet oriented in the (0, 0, 1) direction. In the MoTe2 sheet, Mo6+ is bonded to six equivalent Te2- atoms to form distorted edge-sharing MoTe6 pentagonal pyramids. All Mo–Te bond lengths are 2.71 Å. Te2- is bonded in a 12-coordinate geometry to three equivalent Mo6+ atoms. In the WS2 sheet, W+3.33+ is bonded to six S2- atoms to form distorted edge-sharing WS6 pentagonal pyramids. All W–S bond lengths are 2.47 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted T-shaped geometry to three equivalent W+3.33+ atoms. In the second S2- site, S2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms. In the WSe2 sheet, W+3.33+ is bonded to six equivalent Se2- atoms to form distorted edge-sharing WSe6 pentagonal pyramids. All W–Se bond lengths are 2.57 Å. Se2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms. In the WTe2 sheet, W+3.33+ is bonded to six Te2- atoms to form distorted edge-sharing WTe6 pentagonal pyramids. All W–Te bond lengths are 2.72 Å. There are two inequivalent Te2- sites. In the first Te2- site, Te2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms. In the second Te2- site, Te2- is bonded in a 12-coordinate geometry to three equivalent W+3.33+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Te4MoW3(SeS)2 by Materials Project

WTe2MoTe2WSe2WS2 is Molybdenite-derived structured and crystallizes in the trigonal P3m1 space group. The structure is two-dimensional and consists of one MoTe2 sheet oriented in the (0, 0, 1) direction; one WS2 sheet oriented in the (0, 0, 1) direction; one WSe2 sheet oriented in the (0, 0, 1) direction; and one WTe2 sheet oriented in the (0, 0, 1) direction. In the MoTe2 sheet, Mo6+ is bonded to six equivalent Te2- atoms to form distorted edge-sharing MoTe6 pentagonal pyramids. All Mo–Te bond lengths are 2.71 Å. Te2- is bonded in a 3-coordinate geometry to three equivalent Mo6+ atoms. In the WS2 sheet, W+3.33+ is bonded to six S2- atoms to form distorted edge-sharing WS6 pentagonal pyramids. All W–S bond lengths are 2.47 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted T-shaped geometry to three equivalent W+3.33+ atoms. In the second S2- site, S2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms. In the WSe2 sheet, W+3.33+ is bonded to six equivalent Se2- atoms to form distorted edge-sharing WSe6 pentagonal pyramids. All W–Se bond lengths are 2.57 Å. Se2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms. In the WTe2 sheet, W+3.33+ is bonded to six Te2- atoms to form distorted edge-sharing WTe6 pentagonal pyramids. All W–Te bond lengths are 2.72 Å. There are two inequivalent Te2- sites. In the first Te2- site, Te2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms. In the second Te2- site, Te2- is bonded in a 12-coordinate geometry to three equivalent W+3.33+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Te2MoW3(SeS2)2 by Materials Project

WTe2WSe2WS2MoS2 is Molybdenite-derived structured and crystallizes in the trigonal P3m1 space group. The structure is two-dimensional and consists of one MoS2 sheet oriented in the (0, 0, 1) direction; one WS2 sheet oriented in the (0, 0, 1) direction; one WSe2 sheet oriented in the (0, 0, 1) direction; and one WTe2 sheet oriented in the (0, 0, 1) direction. In the MoS2 sheet, Mo6+ is bonded to six equivalent S2- atoms to form distorted edge-sharing MoS6 pentagonal pyramids. All Mo–S bond lengths are 2.45 Å. S2- is bonded in a 3-coordinate geometry to three equivalent Mo6+ atoms. In the WS2 sheet, W+3.33+ is bonded to six S2- atoms to form distorted edge-sharing WS6 pentagonal pyramids. All W–S bond lengths are 2.45 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a distorted T-shaped geometry to three equivalent W+3.33+ atoms. In the second S2- site, S2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms. In the WSe2 sheet, W+3.33+ is bonded to six equivalent Se2- atoms to form distorted edge-sharing WSe6 pentagonal pyramids. All W–Se bond lengths are 2.55 Å. Se2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms. In the WTe2 sheet, W+3.33+ is bonded to six Te2- atoms to form distorted edge-sharing WTe6 pentagonal pyramids. All W–Te bond lengths are 2.71 Å. There are two inequivalent Te2- sites. In the first Te2- site, Te2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms. In the second Te2- site, Te2- is bonded in a 12-coordinate geometry to three equivalent W+3.33+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Te2MoW3(Se2S)2 by Materials Project

WTe2WSe2MoSe2WS2 is Molybdenite-derived structured and crystallizes in the trigonal P3m1 space group. The structure is two-dimensional and consists of one MoSe2 sheet oriented in the (0, 0, 1) direction; one WS2 sheet oriented in the (0, 0, 1) direction; one WSe2 sheet oriented in the (0, 0, 1) direction; and one WTe2 sheet oriented in the (0, 0, 1) direction. In the MoSe2 sheet, Mo6+ is bonded to six equivalent Se2- atoms to form distorted edge-sharing MoSe6 pentagonal pyramids. All Mo–Se bond lengths are 2.55 Å. Se2- is bonded in a 3-coordinate geometry to three equivalent Mo6+ atoms. In the WS2 sheet, W+3.33+ is bonded to six S2- atoms to form distorted edge-sharing WS6 pentagonal pyramids. All W–S bond lengths are 2.46 Å. There are two inequivalent S2- sites. In the first S2- site, S2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms. In the second S2- site, S2- is bonded in a distorted T-shaped geometry to three equivalent W+3.33+ atoms. In the WSe2 sheet, W+3.33+ is bonded to six equivalent Se2- atoms to form distorted edge-sharing WSe6 pentagonal pyramids. There are three shorter (2.55 Å) and three longer (2.56 Å) W–Se bond lengths. Se2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms. In the WTe2 sheet, W+3.33+ is bonded to six Te2- atoms to form distorted edge-sharing WTe6 pentagonal pyramids. All W–Te bond lengths are 2.71 Å. There are two inequivalent Te2- sites. In the first Te2- site, Te2- is bonded in a 3-coordinate geometry to three equivalent W+3.33+ atoms. In the second Te2- site, Te2- is bonded in a 12-coordinate geometry to three equivalent W+3.33+ atoms.

36 MATERIALS SCIENCE↗