cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.17188/1672475
title: Materials Data on K2NaNdF6 by Materials Project

description: Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations
DOI: 10.17188/1672476
title: Materials Data on Li2In2GeS6 by Materials Project

description: Li2In2GeS6 crystallizes in the monoclinic Cc space group. The structure is three-dimensional. there are two inequivalent Li1+ sites. In the first Li1+ site, Li1+ is bonded to four S2- atoms to form distorted LiS4 trigonal pyramids that share corners with two equivalent LiS4 tetrahedra, corners with two equivalent GeS4 tetrahedra, and corners with six InS4 tetrahedra. There are a spread of Li–S bond distances ranging from 2.56–2.70 Å. In the second Li1+ site, Li1+ is bonded to four S2- atoms to form distorted LiS4 tetrahedra that share corners with two equivalent GeS4 tetrahedra, corners with six InS4 tetrahedra, and corners with two equivalent LiS4 trigonal pyramids. There are a spread of Li–S bond distances ranging from 2.55–2.60 Å. There are two inequivalent In3+ sites. In the first In3+ site, In3+ is bonded to four S2- atoms to form InS4 tetrahedra that share corners with two equivalent InS4 tetrahedra, corners with two equivalent GeS4 tetrahedra, corners with three equivalent LiS4 tetrahedra, and corners with three equivalent LiS4 trigonal pyramids. There are a spread of In–S bond distances ranging from 2.50–2.54 Å. In the second In3+ site, In3+ is bonded to four S2- atoms to form InS4 tetrahedra that share corners with two equivalent InS4 tetrahedra, corners with two equivalent GeS4 tetrahedra, corners with three equivalent LiS4 tetrahedra, and corners with three equivalent LiS4 trigonal pyramids. There are a spread of In–S bond distances ranging from 2.51–2.53 Å. Ge4+ is bonded to four S2- atoms to form GeS4 tetrahedra that share corners with two equivalent LiS4 tetrahedra, corners with four InS4 tetrahedra, and corners with two equivalent LiS4 trigonal pyramids. There are a spread of Ge–S bond distances ranging from 2.21–2.23 Å. There are six inequivalent S2- sites. In the first S2- site, S2- is bonded to two Li1+ and two In3+ atoms to form corner-sharing SLi2In2 tetrahedra. In the second S2- site, S2- is bonded to two Li1+ and two In3+ atoms to form distorted corner-sharing SLi2In2 tetrahedra. In the third S2- site, S2- is bonded in a distorted trigonal non-coplanar geometry to one Li1+, one In3+, and one Ge4+ atom. In the fourth S2- site, S2- is bonded in a trigonal non-coplanar geometry to one Li1+, one In3+, and one Ge4+ atom. In the fifth S2- site, S2- is bonded in a distorted trigonal non-coplanar geometry to one Li1+, one In3+, and one Ge4+ atom. In the sixth S2- site, S2- is bonded in a trigonal non-coplanar geometry to one Li1+, one In3+, and one Ge4+ atom.
DOI: 10.17188/1672477
title: Materials Data on Nd2Fe3CoSi4 by Materials Project

description: Nd2Fe3CoSi4 crystallizes in the tetragonal P-4m2 space group. The structure is three-dimensional. Nd3+ is bonded in a distorted body-centered cubic geometry to eight Si4- atoms. All Nd–Si bond lengths are 3.13 Å. There are two inequivalent Fe+2.67+ sites. In the first Fe+2.67+ site, Fe+2.67+ is bonded to four equivalent Si4- atoms to form a mixture of edge and corner-sharing FeSi4 tetrahedra. All Fe–Si bond lengths are 2.28 Å. In the second Fe+2.67+ site, Fe+2.67+ is bonded to four equivalent Si4- atoms to form FeSi4 tetrahedra that share corners with four equivalent FeSi4 tetrahedra and edges with four equivalent CoSi4 tetrahedra. All Fe–Si bond lengths are 2.28 Å. Co2+ is bonded to four equivalent Si4- atoms to form CoSi4 tetrahedra that share corners with four equivalent CoSi4 tetrahedra and edges with four equivalent FeSi4 tetrahedra. All Co–Si bond lengths are 2.28 Å. There are two inequivalent Si4- sites. In the first Si4- site, Si4- is bonded in a 9-coordinate geometry to four equivalent Nd3+, two equivalent Fe+2.67+, two equivalent Co2+, and one Si4- atom. The Si–Si bond length is 2.68 Å. In the second Si4- site, Si4- is bonded in a 9-coordinate geometry to four equivalent Nd3+, four equivalent Fe+2.67+, and one Si4- atom.
DOI: 10.17188/1672478
title: Materials Data on Ba3Ti(FeO4)2 by Materials Project

description: Ba3Ti(FeO4)2 crystallizes in the orthorhombic Ama2 space group. The structure is three-dimensional. there are two inequivalent Ba2+ sites. In the first Ba2+ site, Ba2+ is bonded in a distorted q6 geometry to eleven O2- atoms. There are a spread of Ba–O bond distances ranging from 2.85–3.06 Å. In the second Ba2+ site, Ba2+ is bonded in a 10-coordinate geometry to ten O2- atoms. There are a spread of Ba–O bond distances ranging from 2.65–3.20 Å. Ti4+ is bonded to six O2- atoms to form TiO6 octahedra that share corners with six equivalent FeO5 trigonal bipyramids. There are a spread of Ti–O bond distances ranging from 1.98–2.04 Å. Fe3+ is bonded to five O2- atoms to form distorted FeO5 trigonal bipyramids that share corners with three equivalent TiO6 octahedra and an edgeedge with one FeO5 trigonal bipyramid. The corner-sharing octahedra tilt angles range from 2–13°. There are a spread of Fe–O bond distances ranging from 1.89–2.05 Å. There are five inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to four Ba2+ and two equivalent Fe3+ atoms. In the second O2- site, O2- is bonded in a 2-coordinate geometry to four Ba2+ and two equivalent Fe3+ atoms. In the third O2- site, O2- is bonded in a 2-coordinate geometry to four Ba2+, one Ti4+, and one Fe3+ atom. In the fourth O2- site, O2- is bonded in a 2-coordinate geometry to four Ba2+, one Ti4+, and one Fe3+ atom. In the fifth O2- site, O2- is bonded in a distorted linear geometry to four Ba2+, one Ti4+, and one Fe3+ atom.
DOI: 10.17188/1672479
title: Materials Data on Cu3Sb4(OF)6 by Materials Project

description: Cu3Sb4(OF)6 crystallizes in the cubic I-43m space group. The structure is three-dimensional. Cu+1.33+ is bonded to two equivalent O2- and four equivalent F1- atoms to form corner-sharing CuO2F4 octahedra. The corner-sharing octahedral tilt angles are 0°. Both Cu–O bond lengths are 2.01 Å. All Cu–F bond lengths are 2.04 Å. Sb+3.50+ is bonded in a distorted T-shaped geometry to three equivalent O2- atoms. All Sb–O bond lengths are 2.03 Å. O2- is bonded in a distorted trigonal planar geometry to one Cu+1.33+ and two equivalent Sb+3.50+ atoms. F1- is bonded in a linear geometry to two equivalent Cu+1.33+ atoms.
DOI: 10.17188/1672480
title: Materials Data on RbSc(PO4)2 by Materials Project

description: RbSc(PO4)2 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. Rb is bonded in a 7-coordinate geometry to eleven O atoms. There are a spread of Rb–O bond distances ranging from 2.99–3.63 Å. Sc is bonded to six O atoms to form ScO6 octahedra that share corners with six PO4 tetrahedra. There are a spread of Sc–O bond distances ranging from 2.08–2.11 Å. There are two inequivalent P sites. In the first P site, P is bonded to four O atoms to form PO4 tetrahedra that share corners with three equivalent ScO6 octahedra. The corner-sharing octahedra tilt angles range from 10–32°. There is three shorter (1.54 Å) and one longer (1.55 Å) P–O bond length. In the second P site, P is bonded to four O atoms to form PO4 tetrahedra that share corners with three equivalent ScO6 octahedra. The corner-sharing octahedra tilt angles range from 21–45°. There is two shorter (1.54 Å) and two longer (1.55 Å) P–O bond length. There are eight inequivalent O sites. In the first O site, O is bonded in a distorted bent 150 degrees geometry to one Rb, one Sc, and one P atom. In the second O site, O is bonded in a distorted bent 150 degrees geometry to one Rb, one Sc, and one P atom. In the third O site, O is bonded in a 2-coordinate geometry to one Rb, one Sc, and one P atom. In the fourth O site, O is bonded in a single-bond geometry to three equivalent Rb and one P atom. In the fifth O site, O is bonded in a linear geometry to one Sc and one P atom. In the sixth O site, O is bonded in a bent 150 degrees geometry to one Rb, one Sc, and one P atom. In the seventh O site, O is bonded in a bent 150 degrees geometry to one Rb, one Sc, and one P atom. In the eighth O site, O is bonded in a distorted single-bond geometry to three equivalent Rb and one P atom.
DOI: 10.17188/1672481
title: Materials Data on Fe3(PO4)2 by Materials Project

description: Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations
DOI: 10.17188/1672482
title: Materials Data on LiMnCo3O8 by Materials Project

description: Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations
DOI: 10.17188/1672483
title: Materials Data on TaCr3(CuS4)2 by Materials Project

description: Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations
DOI: 10.17188/1672484
title: Materials Data on Li3Ti2NiO6 by Materials Project

description: Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations
DOI: 10.17188/1672485
title: Materials Data on La2TiCrO6 by Materials Project

description: Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations
DOI: 10.17188/1672487
title: Materials Data on Li9Co13O28 by Materials Project

description: Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations
DOI: 10.17188/1672488
title: Materials Data on Sn2PdAu by Materials Project

description: PdAuSn2 crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. Pd is bonded in a body-centered cubic geometry to two equivalent Au and six equivalent Sn atoms. Both Pd–Au bond lengths are 2.84 Å. All Pd–Sn bond lengths are 2.81 Å. Au is bonded in a distorted body-centered cubic geometry to two equivalent Pd and six equivalent Sn atoms. All Au–Sn bond lengths are 2.87 Å. Sn is bonded in a 6-coordinate geometry to three equivalent Pd and three equivalent Au atoms.
DOI: 10.17188/1672489
title: Materials Data on Nd9Ga4 by Materials Project

description: Nd9Ga4 crystallizes in the tetragonal I4/m space group. The structure is three-dimensional. there are three inequivalent Nd sites. In the first Nd site, Nd is bonded in a 1-coordinate geometry to four equivalent Ga atoms. There are a spread of Nd–Ga bond distances ranging from 3.05–3.55 Å. In the second Nd site, Nd is bonded in a square co-planar geometry to four equivalent Ga atoms. All Nd–Ga bond lengths are 3.12 Å. In the third Nd site, Nd is bonded in a 3-coordinate geometry to five equivalent Ga atoms. There are a spread of Nd–Ga bond distances ranging from 3.08–3.80 Å. Ga is bonded in a 10-coordinate geometry to ten Nd atoms.
DOI: 10.17188/1672490
title: Materials Data on YbAl7Fe5 by Materials Project

description: YbFe5Al7 crystallizes in the orthorhombic Imm2 space group. The structure is three-dimensional. Yb is bonded in a 4-coordinate geometry to ten Fe and ten Al atoms. There are a spread of Yb–Fe bond distances ranging from 3.21–3.34 Å. There are a spread of Yb–Al bond distances ranging from 2.85–3.21 Å. There are two inequivalent Fe sites. In the first Fe site, Fe is bonded in a 12-coordinate geometry to two equivalent Yb, three Fe, and seven Al atoms. There are a spread of Fe–Fe bond distances ranging from 2.48–2.54 Å. There are a spread of Fe–Al bond distances ranging from 2.47–2.65 Å. In the second Fe site, Fe is bonded to two equivalent Yb, four equivalent Fe, and six Al atoms to form distorted edge-sharing FeYb2Al6Fe4 cuboctahedra. There are a spread of Fe–Al bond distances ranging from 2.58–2.71 Å. There are five inequivalent Al sites. In the first Al site, Al is bonded in a 5-coordinate geometry to one Yb, four equivalent Fe, and five Al atoms. There are a spread of Al–Al bond distances ranging from 2.68–2.84 Å. In the second Al site, Al is bonded in a 7-coordinate geometry to one Yb, six Fe, and three Al atoms. Both Al–Al bond lengths are 2.88 Å. In the third Al site, Al is bonded in a 10-coordinate geometry to one Yb, five Fe, and four Al atoms. There are three shorter (2.75 Å) and one longer (2.78 Å) Al–Al bond lengths. In the fourth Al site, Al is bonded in a 12-coordinate geometry to two equivalent Yb, four equivalent Fe, and six Al atoms. Both Al–Al bond lengths are 2.70 Å. In the fifth Al site, Al is bonded in a 12-coordinate geometry to two equivalent Yb, five Fe, and five Al atoms.
DOI: 10.17188/1672491
title: Materials Data on YbAgPb by Materials Project

description: YbAgPb crystallizes in the trigonal P-3m1 space group. The structure is three-dimensional. Yb is bonded in a 9-coordinate geometry to six equivalent Ag and three equivalent Pb atoms. There are three shorter (3.23 Å) and three longer (3.35 Å) Yb–Ag bond lengths. All Yb–Pb bond lengths are 3.24 Å. Ag is bonded in a 10-coordinate geometry to six equivalent Yb, three equivalent Ag, and one Pb atom. All Ag–Ag bond lengths are 2.80 Å. The Ag–Pb bond length is 3.28 Å. Pb is bonded in a 7-coordinate geometry to three equivalent Yb, one Ag, and three equivalent Pb atoms. All Pb–Pb bond lengths are 3.12 Å.
DOI: 10.17188/1672492
title: Materials Data on PSN(Cl2O)2 by Materials Project

description: PNS(OCl2)2 is T-50 Boron-like structured and crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of twenty-four PNS(OCl2)2 clusters. P5+ is bonded to one N5+ and three Cl1- atoms to form distorted PNCl3 tetrahedra that share a cornercorner with one SNClO2 tetrahedra. The P–N bond length is 1.57 Å. There are a spread of P–Cl bond distances ranging from 1.98–2.00 Å. N5+ is bonded in a distorted single-bond geometry to one P5+ and one S2- atom. The N–S bond length is 1.59 Å. S2- is bonded to one N5+, two O2-, and one Cl1- atom to form distorted SNClO2 tetrahedra that share a cornercorner with one PNCl3 tetrahedra. Both S–O bond lengths are 1.44 Å. The S–Cl bond length is 2.10 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a single-bond geometry to one S2- atom. In the second O2- site, O2- is bonded in a single-bond geometry to one S2- atom. There are four inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a single-bond geometry to one S2- atom. In the second Cl1- site, Cl1- is bonded in a single-bond geometry to one P5+ atom. In the third Cl1- site, Cl1- is bonded in a single-bond geometry to one P5+ atom. In the fourth Cl1- site, Cl1- is bonded in a single-bond geometry to one P5+ atom.
DOI: 10.17188/1672493
title: Materials Data on Mn2GaMo by Materials Project

description: MoMn2Ga crystallizes in the orthorhombic Immm space group. The structure is one-dimensional and consists of two MoMn2Ga ribbons oriented in the (0, 1, 0) direction. Mo is bonded in a linear geometry to two equivalent Mn atoms. Both Mo–Mn bond lengths are 2.87 Å. Mn is bonded in a linear geometry to one Mo and one Ga atom. The Mn–Ga bond length is 2.42 Å. Ga is bonded in a linear geometry to two equivalent Mn atoms.
DOI: 10.17188/1672495
title: Materials Data on LiV2OF5 by Materials Project

description: Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations
DOI: 10.17188/1672496
title: Materials Data on Ti4Fe10O21 by Materials Project

description: Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations
DOI: 10.17188/1672500
title: Materials Data on ThUB8 by Materials Project

description: UThB8 crystallizes in the orthorhombic Cmmm space group. The structure is three-dimensional. U is bonded in a 12-coordinate geometry to eighteen B atoms. There are a spread of U–B bond distances ranging from 2.70–3.03 Å. Th is bonded in a 8-coordinate geometry to eighteen B atoms. There are a spread of Th–B bond distances ranging from 2.75–3.01 Å. There are five inequivalent B sites. In the first B site, B is bonded in a 1-coordinate geometry to two equivalent U, two equivalent Th, and five B atoms. There are a spread of B–B bond distances ranging from 1.62–1.78 Å. In the second B site, B is bonded in a 9-coordinate geometry to two equivalent U, two equivalent Th, and five B atoms. There are a spread of B–B bond distances ranging from 1.70–1.88 Å. In the third B site, B is bonded in a 9-coordinate geometry to two equivalent U, two equivalent Th, and five B atoms. The B–B bond length is 1.72 Å. In the fourth B site, B is bonded in a distorted trigonal planar geometry to four equivalent U, two equivalent Th, and three B atoms. The B–B bond length is 1.76 Å. In the fifth B site, B is bonded in a 3-coordinate geometry to two equivalent U, four equivalent Th, and three B atoms. The B–B bond length is 1.81 Å.
DOI: 10.17188/1672501
title: Materials Data on V12PbO30 by Materials Project

description: Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations
DOI: 10.17188/1672502
title: Materials Data on K3CO by Materials Project

description: OK3C is (Cubic) Perovskite structured and crystallizes in the cubic Pm-3m space group. The structure is three-dimensional and consists of one methane molecule and one OK3 framework. In the OK3 framework, K is bonded in a linear geometry to two equivalent O atoms. Both K–O bond lengths are 2.62 Å. O is bonded to six equivalent K atoms to form corner-sharing OK6 octahedra. The corner-sharing octahedral tilt angles are 0°.
DOI: 10.17188/1672503
title: Materials Data on CdCu2SnS4 by Materials Project

description: Cu2CdSnS4 is Stannite structured and crystallizes in the tetragonal I-42m space group. The structure is three-dimensional. Cu1+ is bonded to four equivalent S2- atoms to form CuS4 tetrahedra that share corners with four equivalent CuS4 tetrahedra, corners with four equivalent CdS4 tetrahedra, and corners with four equivalent SnS4 tetrahedra. All Cu–S bond lengths are 2.32 Å. Cd2+ is bonded to four equivalent S2- atoms to form CdS4 tetrahedra that share corners with four equivalent SnS4 tetrahedra and corners with eight equivalent CuS4 tetrahedra. All Cd–S bond lengths are 2.57 Å. Sn4+ is bonded to four equivalent S2- atoms to form SnS4 tetrahedra that share corners with four equivalent CdS4 tetrahedra and corners with eight equivalent CuS4 tetrahedra. All Sn–S bond lengths are 2.46 Å. S2- is bonded to two equivalent Cu1+, one Cd2+, and one Sn4+ atom to form corner-sharing SCdCu2Sn tetrahedra.
DOI: 10.17188/1672504
title: Materials Data on LiTi2N3 by Materials Project

description: LiTi2N3 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. Li1+ is bonded to five N3- atoms to form LiN5 trigonal bipyramids that share corners with two equivalent LiN5 trigonal bipyramids, corners with six equivalent TiN5 trigonal bipyramids, edges with two equivalent LiN5 trigonal bipyramids, and edges with four equivalent TiN5 trigonal bipyramids. There are a spread of Li–N bond distances ranging from 2.10–2.29 Å. Ti4+ is bonded to five N3- atoms to form TiN5 trigonal bipyramids that share corners with three equivalent LiN5 trigonal bipyramids, corners with five equivalent TiN5 trigonal bipyramids, edges with two equivalent LiN5 trigonal bipyramids, and edges with four equivalent TiN5 trigonal bipyramids. There are a spread of Ti–N bond distances ranging from 1.88–2.09 Å. There are two inequivalent N3- sites. In the first N3- site, N3- is bonded to three equivalent Li1+ and two equivalent Ti4+ atoms to form a mixture of corner and edge-sharing NLi3Ti2 trigonal bipyramids. In the second N3- site, N3- is bonded to one Li1+ and four equivalent Ti4+ atoms to form a mixture of corner and edge-sharing NLiTi4 trigonal bipyramids.
DOI: 10.17188/1672505
title: Materials Data on CrH4C4NO10 by Materials Project

description: CrC4NH4O10 crystallizes in the monoclinic C2/m space group. The structure is three-dimensional. Cr3+ is bonded in an octahedral geometry to six O2- atoms. There are four shorter (1.99 Å) and two longer (2.04 Å) Cr–O bond lengths. C4+ is bonded in a bent 120 degrees geometry to two O2- atoms. There is one shorter (1.22 Å) and one longer (1.32 Å) C–O bond length. N3- is bonded to eight equivalent O2- atoms to form distorted edge-sharing NO8 hexagonal bipyramids. There are four shorter (3.10 Å) and four longer (3.12 Å) N–O bond lengths. H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Cr3+ and one C4+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one C4+ and two equivalent N3- atoms. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to one Cr3+ and two equivalent H1+ atoms.
DOI: 10.17188/1672507
title: Materials Data on NaCa2Al by Materials Project

description: NaCa2Al crystallizes in the orthorhombic Immm space group. The structure is one-dimensional and consists of two NaCa2Al ribbons oriented in the (1, 0, 0) direction. Na is bonded in a linear geometry to two equivalent Ca atoms. Both Na–Ca bond lengths are 3.60 Å. Ca is bonded in a linear geometry to one Na and one Al atom. The Ca–Al bond length is 2.92 Å. Al is bonded in a linear geometry to two equivalent Ca atoms.
DOI: 10.17188/1672509
title: Materials Data on Li2MnFe(BO3)2 by Materials Project

description: Computed materials data using density functional theory calculations. These calculations determine the electronic structure of bulk materials by solving approximations to the Schrodinger equation. For more information, see https://materialsproject.org/docs/calculations
DOI: 10.17188/1672511
title: Materials Data on Tm3Ge by Materials Project

description: Tm3Ge is Uranium Silicide-like structured and crystallizes in the hexagonal P6_3/mmc space group. The structure is three-dimensional. Tm is bonded in a distorted see-saw-like geometry to four equivalent Ge atoms. There are two shorter (3.22 Å) and two longer (3.29 Å) Tm–Ge bond lengths. Ge is bonded to twelve equivalent Tm atoms to form a mixture of face and corner-sharing GeTm12 cuboctahedra.