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CsLa crystallizes in the hexagonal P6_3mc space group. The structure is zero-dimensional and consists of two CsLa clusters. Cs is bonded in a distorted single-bond geometry to one La atom. The Cs–La bond length is 3.58 Å. La is bonded in a distorted single-bond geometry to one Cs atom.
(ThS)2P crystallizes in the tetragonal P4/mmm space group. The structure is zero-dimensional and consists of one phosphine molecule and two ThS clusters. In each ThS cluster, Th is bonded in a single-bond geometry to one S atom. The Th–S bond length is 2.33 Å. S is bonded in a single-bond geometry to one Th atom.
(US)2Ge crystallizes in the tetragonal P4/mmm space group. The structure is zero-dimensional and consists of one germanium molecule and two US clusters. In each US cluster, U is bonded in a single-bond geometry to one S atom. The U–S bond length is 2.35 Å. S is bonded in a single-bond geometry to one U atom.
CdCN2 crystallizes in the trigonal R3m space group. The structure is zero-dimensional and consists of three hydrogen cyanide molecules and three CdN clusters. In each CdN cluster, Cd2+ is bonded in a distorted single-bond geometry to one N3- atom. The Cd–N bond length is 2.13 Å. N3- is bonded in a single-bond geometry to one Cd2+ atom.
Many important and challenging problems in combinatorial optimization (CO) can be expressed as graph search problems, in which graph vertices represent full or partial solutions and edges represent decisions that connect them. Graph structure not only introduces strong relational inductive biases for learning (Battaglia et al., 2018) - in this context, by providing a way to explicitly model the value of transitioning (along edges) between one search state (vertex) and the next - but lends itself to problems both with and without clearly defined algebraic structure. For example, classic CO problems on graphs such as the Traveling Salesman Problem (TSP) can be expressed as either pure graph search or integer programs. Other problems, however, such as molecular optimization, do no have concise algebraic formulations and yet are readily implemented as a graph search (V. et al., 2022; Zhou et al., 2019). Such "model-free" problems constitute a large fraction of modern reinforcement learning (RL) research owing to the fact that it is often much easier to write a forward simulation that expresses all of the state transitions and rewards, than to write down the precise mathematical expression of the full optimization problem. In the case of molecular optimization, for example, one can use domain knowledge alongside existing software libraries to model the effect of adding a single bond or atom to an existing but incomplete molecule, and let the RL algorithm build a model of how good a given decision is by "experiencing" the simulated environment many times through. In contrast, a model-based mathematical formulation that fully expresses all the chemical and physical constraints is intractable. In recent years, RL has emerged as an effective paradigm for optimizing searches over graphs and led to state-of-the-art heuristics for games like Go and chess, as well as for classical CO problems such as the TSP. This combination of graph search and RL, while powerful, requires non-trivial software to execute, especially when combining advanced state representations such as Graph Neural Networks (GNN) with scalable RL algorithms.
Abstract The post-stishovite transition is a classic pseudo-proper typed ferroelastic transition with a symmetry-breaking spontaneous strain. This transition has been studied using high-pressure spontaneous strains, optic modes, and elastic moduli (Cij) based on the Landau modeling, but its atomistic information and structural distortion remain poorly understood. Here we have conducted synchrotron single-crystal X-ray diffraction measurements on stishovite crystals up to 75.3 GPa in a diamond-anvil cell. Analysis of the data reveals atomic positions, bond lengths, bond angles, and variations of SiO6 octahedra across the transition at high pressure. Our results show that the O coordinates split at ~51.4 GPa, where the apical and equatorial Si-O bond lengths cross over, the SiO6 octahedral distortion vanishes, and the SiO6 octahedra start to rotate about the c axis. Moreover, distortion mode analysis shows that an in-plane stretching distortion (GM1+ mode) occurs in the stishovite structure at high pressure while a rotational distortion (GM2+ mode) becomes dominant in the post-stishovite structure. These results are used to correlate with elastic moduli and Landau parameters (symmetry-breaking strain e1–e2 and order parameter Q) to provide atomistic insight into the ferroelastic transition. When the bond lengths of two Si-O bonds are equal due to the contribution from the GM1+ stretching mode, C11 converges with C12, and the shear wave VS1[110] polarizing along [110] and propagating along [110] vanishes. Values of e1–e2 and Q are proportional to the SiO6 rotation angle from the occurrence of the GM1+ rotational mode in the post-stishovite structure. Our results on the pseudo-proper type transition are also compared with that for the proper type in albite and improper type in CaSiO3 perovskite. The symmetry-breaking strain, in all these types of transitions, arises as the primary effect from the structural angle (such as SiO6 rotation or lattice constant angle) and its relevant distortion mode in the low-symmetry ferroelastic phase.
Project Goal and Objective. The demand for energy and for an upgraded energy infrastructure has steadily grown, as have the needs for energy independence and alternatives to our reliance on petroleum. Hydrogen is considered the most viable fuels for wide-scale implementation in the near future as it is less-polluting, non-toxic, and has more stored energy than petroleum. It is envisioned that hydrogen can eventually become the prime energy carrier, integrating the transportation, grid, and chemical sectors in a way that improves resiliency, diversifies feedstocks, and affords new economic opportunities. A key remaining challenge is the development materials with enhanced gravimetric and volumetric hydrogen storage capacities that offer a higher performance than compressed gas. These materials would eliminate the need for large-scale compression, thereby dramatically reducing the footprint and cost of gas storage. The high gravimetric and volumetric hydrogen capacities of complex hydrides has prompted an intensive investigation of the potential of this class of materials as hydrogen storage media over the past 25 years. Among the many complex hydrides that have been explored, magnesium borohydride, Mg(BH 4 ) 2 , has been found to possess the best combination of practical thermodynamic properties. These include a gravimetric H 2 density of 14.9 wt% H 2 and thermodynamics for the dehydrogenation of Mg(BH 4 ) 2 to MgB 2 (equation 1) (ΔH° = 39 kJ/mol H 2 , ΔS = 112 J/K mol H 2 ) which lie in the narrow window required Mg(BH 4 ) 2 $\Leftrightarrow$ MgB 2 + 4 H 2 (1) for reversibility under moderate pressure and temperature. However, overcoming the extremely slow kinetics of the reversible release of hydrogen by this material in the solid state is a daunting challenge. At temperatures greater than 400 °C, the borohydride releases up to 14 wt% hydrogen giving MgB 2 . We discovered that the direct re-hydrogenation of MgB 2 to Mg(BH 4 ) 2 can be accomplished under 950 bar H 2 at 400 °C. While this demonstrated that complete reversibility can be achieved, the conditions employed are far too extreme for commercial hydrogen storage applications. More recently, we found through US DOE funded research projects (EERE HyMARC and HySCOR), that hydrogen cycling, can be accomplish at much milder conditions upon modification of the borohydride or boride. Guided by these discoveries these discoveries, the objective of this research project was to obtain key information that will enable the development of a model of reversible hydrogenation of MgB 2 to Mg(BH 4 ) 2 . The ultimate goal of our efforts is to attain a model of this transformation that can be utilized to accelerate development further advanced materials. This project directly follows on discoveries that were made over the course of a US DOE, EERE HyMARC project that was focused on improvement of the hydrogen cycling kinetics of modified MgB 2 . We found that that mechanical milling with graphene results the desired, pronounced kinetic enhancement. The dramatic lowering of the conditions required for the hydrogenation of MgB 2 is a significant step towards overcoming its chemical inertness allowing its development as a practical onboard hydrogen storage material. However, the exact nature of the modification(s) of MgB 2 that is responsible for its activation towards hydrogenation is completely unknown. This situation is not unique, as efforts to develop hydrogen storage materials typically have a narrow focus rather than a comprehensive approach that takes atomic level bonding and structure; molecular dynamics; long range, nano- and mesoscale-structure and their interconnection all into account. The goal of this project was the development of a comprehensive, multi-scale computational model of reversible hydrogenation of MgB 2 to Mg(BH 4 ) 2 that can be utilized for development of higher performance versions of the modified material. Development of the model requires determination of: 1) the bulk, nano-scale, and meso-scale structural changes occurring at elevated pressure following mechano-chemical modification of MgB 2 ; 2) the reaction pathway of the reversible hydrogenation of MgB 2 to Mg(BH 4 ) 2 ; 3) the effect of elevated pressure and mechano-chemical modification on the chemical reaction pathways; 4) the interactions at solid-gas interfaces; and particle surfaces; and 5) the kinetics and thermodynamic parameters associated with each step of the hydrogenation reaction pathway. This investigation required advanced techniques as preliminary, standard XRD, 11 B NMR, and FTIR analysis showed no signs of material modification. In order to gain this level of understanding of modified MgB 2 , required the teaming of a diverse group of experts and state-of-the art experimental capabilities at the University of Hawaii at Manoa (UHM) and collaborating National Laboratories: Craig Jensen , Department of Chemistry (PI and Project Director), solid state, solution, and high pressure NMR spectroscopy; solid-state synthesis; and high pressure hydrogenation (collaboration with SNL); Godwin Severa , Hawaii Natural Energy Institute (co-PI) calorimetry; infrared and Raman spectroscopy (collaboration with NREL); Dera , high pressure X-ray diffraction including in situ experiments (collaboration with ANL); Hope Ishii , Hawaii Institute of Geophysics electron microscopy investigations (collaboration with LBNL); and Joe Brown , Mechanical Engineering , material electronic structure and electric field effects.
The status of an explosive seam welding process, which was developed and evaluated for a wide range of metal joining opportunities, is summarized. The process employs very small quantities of explosive in a ribbon configuration to accelerate a long-length, narrow area of sheet stock into a high-velocity, angular impact against a second sheet. At impact, the oxide films of both surface are broken up and ejected by the closing angle to allow atoms to bond through the sharing of valence electrons. This cold-working process produces joints having parent metal properties, allowing a variety of joints to be fabricated that achieve full strength of the metals employed. Successful joining was accomplished in all aluminum alloys, a wide variety of iron and steel alloys, copper, brass, titanium, tantalum, zirconium, niobium, telerium, and columbium. Safety issues were addressed and are as manageable as many currently accepted joining processes.
Nanotechnology has created a demand for new fabrication methods with an emphasis on simple, low-cost techniques. Directional solidification of eutectics (DSE) is an unconventional approach in comparison to low-temperature biomimetic approaches. A technical challenge for DSE is producing microstructural architectures on the nanometer scale. In both processes, the driving force is the minimization of Gibb's free energy. Selfassembly by biomimetic approaches depends on weak interaction forces between organic molecules to define the architectural structure. The architectural structure for solidification depends on strong chemical bonding between atoms. Constituents partition into atomic-level arrangements at the liquid-solid interface to form polyphase structures, and this atomic-level arrangement at the liquid-solid interface is controlled by atomic diffusion and total undercooling due to composition (diffusion), kinetics, and curvature of the boundary phases. Judicious selection of the materials system and control of the total undercooling are the keys to producing structures on the nanometer scale. The silicon-titanium silicide (Si-TiSi2) eutectic forms a rod structure under isothermal cooling conditions. At the NASA Glenn Research Center, directional solidification was employed along with a thermal gradient to promote uniform rods oriented with the thermal gradient. The preceding photomicrograph shows the typical transverse microstructure of a solidified Si-TiSi2 eutectic composition. The dark and light gray regions are Si and TiSi2, respectively. Preferred rod orientation along the thermal gradient was poor. The ordered TiSi2 rods have a narrow distribution in diameter of 2 to 3 m, as shown. The rod diameter showed a weak dependence on process conditions. Anisotropic etch behavior between different phases provides the opportunity to fabricate structures with high aspect ratios. The photomicrographs show the resulting microstructure after a wet chemical etch and a dry plasma etch. The wet chemical etches the silicon away, exposing the TiSi2 rods, whereas plasma etching preferentially etches the Si-TiSi2 interface to form a crater. The porous architectures are applicable to fabricating microdevices or creating templates for part fabrication. The porous rod structure can serve as a platform for fabricating microplasma devices for propulsion or microheat exchangers and for fabricating microfilters for miniatured chemical reactors. Although more work is required, self-assembly from DSE can have a role in microdevice fabrication.
A new approach is presented for the development of classical interatomic potentials using physically-informed neural networks (PINN) combined with an analytical bond-order atomic interaction model. Due to the strong physical underpinnings, the PINN potentials demonstrate much better transferability than the existing machine-learning potentials while drastically improving the accuracy in comparison with traditional potentials. PINN potentials can be constructed for both metallic and covalent materials in a unified manner. A number of applications of PINN potentials to large-scale molecular dynamics and Monte Carlo simulations and calculation of thermal and mechanical properties of diverse materials are demonstrated. Some of the specific materials systems include silicon and aluminum, as well as alloys and compounds. Computational aspects of PINN potentials are discussed and future developments in this field are outlined.
Protein coordinated iron-sulfur clusters drive electron flow within metabolic pathways for organisms throughout the tree of life. It is not known how iron-sulfur clusters were first incorporated into proteins. Structural analogies to iron-sulfde minerals present on early Earth, suggest a connection in the evolution of both proteins and minerals. The availability of large protein and mineral crystallographic structure data sets, provides an opportunity to explore co-evolution of proteins and minerals on a large-scale using informatics approaches. However, quantitative comparisons are confounded by the infnite, repeating nature of the mineral lattice, in contrast to metal clusters in proteins, which are fnite in size. We address this problem using the Niggli reduction to transform a mineral lattice to a fnite, unique structure that when translated reproduces the crystal lattice. Protein and reduced mineral structures were represented as quotient graphs with the edges and nodes corresponding to bonds and atoms, respectively. We developed a graph theory-based method to calculate the maximum common connected edge subgraph (MCCES) between mineral and protein quotient graphs. MCCES can accommodate differences in structural volumes and easily allows additional chemical criteria to be considered when calculating similarity. To account for graph size differences, we use the Tversky similarity index. Using consistent criteria, we found little similarity between putative ancient iron-sulfur protein clusters and iron-sulfur mineral lattices, suggesting these metal sites are not as evolutionarily connected as once thought. We discuss possible evolutionary implications of these findings in addition to suggesting an alternative proxy, mineral surfaces, for better understanding the coevolution of the geosphere and biosphere
Systems and methods for building passive and active electronics with diamond-like carbon (DLC) coatings are provided herein. DLC may be layered upon substrates to form various components of electronic devices. Passive components such as resistors, capacitors, and inductors may be built using DLC as a dielectric or as an insulating layer. Active components such as diodes and transistors may be built with the DLC acting substantially like a semiconductor. The amount of sp 2 and sp 3 bonded carbon atoms may be varied to modify the properties of the DLC for various electronic components.
Si12CO24 is Low Tridymite-derived structured and crystallizes in the monoclinic Cm space group. The structure is three-dimensional. there are eight inequivalent Si sites. In the first Si site, Si is bonded to four O atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.62–1.64 Å. In the second Si site, Si is bonded to four O atoms to form corner-sharing SiO4 tetrahedra. There is one shorter (1.62 Å) and three longer (1.63 Å) Si–O bond length. In the third Si site, Si is bonded to four O atoms to form corner-sharing SiO4 tetrahedra. All Si–O bond lengths are 1.62 Å. In the fourth Si site, Si is bonded to four O atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.61–1.63 Å. In the fifth Si site, Si is bonded to four O atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.61–1.69 Å. In the sixth Si site, Si is bonded to four O atoms to form corner-sharing SiO4 tetrahedra. There is two shorter (1.62 Å) and two longer (1.63 Å) Si–O bond length. In the seventh Si site, Si is bonded to four O atoms to form corner-sharing SiO4 tetrahedra. There are a spread of Si–O bond distances ranging from 1.61–1.70 Å. In the eighth Si site, Si is bonded to four O atoms to form corner-sharing SiO4 tetrahedra. There is two shorter (1.62 Å) and two longer (1.63 Å) Si–O bond length. C is bonded in a single-bond geometry to one O atom. The C–O bond length is 1.77 Å. There are fourteen inequivalent O sites. In the first O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the second O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the third O site, O is bonded in a distorted T-shaped geometry to two Si and one C atom. In the fourth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the fifth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the sixth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the seventh O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the eighth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the ninth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the tenth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the eleventh O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the twelfth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the thirteenth O site, O is bonded in a bent 150 degrees geometry to two Si atoms. In the fourteenth O site, O is bonded in a bent 150 degrees geometry to two Si atoms.
Rh7Pb2BiO15 crystallizes in the orthorhombic Cmcm space group. The structure is three-dimensional. there are six inequivalent Rh+3.29+ sites. In the first Rh+3.29+ site, Rh+3.29+ is bonded to six O2- atoms to form edge-sharing RhO6 octahedra. All Rh–O bond lengths are 2.05 Å. In the second Rh+3.29+ site, Rh+3.29+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing RhO6 octahedra. The corner-sharing octahedral tilt angles are 55°. There are a spread of Rh–O bond distances ranging from 2.02–2.06 Å. In the third Rh+3.29+ site, Rh+3.29+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing RhO6 octahedra. The corner-sharing octahedral tilt angles are 56°. There are a spread of Rh–O bond distances ranging from 2.03–2.07 Å. In the fourth Rh+3.29+ site, Rh+3.29+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing RhO6 octahedra. The corner-sharing octahedral tilt angles are 55°. There are a spread of Rh–O bond distances ranging from 2.04–2.06 Å. In the fifth Rh+3.29+ site, Rh+3.29+ is bonded to six O2- atoms to form a mixture of corner and edge-sharing RhO6 octahedra. The corner-sharing octahedral tilt angles are 54°. There are two shorter (2.04 Å) and four longer (2.05 Å) Rh–O bond lengths. In the sixth Rh+3.29+ site, Rh+3.29+ is bonded to six O2- atoms to form a mixture of corner and face-sharing RhO6 octahedra. The corner-sharing octahedra tilt angles range from 54–56°. There are a spread of Rh–O bond distances ranging from 2.03–2.16 Å. There are three inequivalent Pb2+ sites. In the first Pb2+ site, Pb2+ is bonded in a distorted rectangular see-saw-like geometry to four O2- atoms. There are two shorter (2.38 Å) and two longer (2.43 Å) Pb–O bond lengths. In the second Pb2+ site, Pb2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are two shorter (2.44 Å) and four longer (2.67 Å) Pb–O bond lengths. In the third Pb2+ site, Pb2+ is bonded in a 6-coordinate geometry to six O2- atoms. There are a spread of Pb–O bond distances ranging from 2.48–2.71 Å. Bi3+ is bonded in a rectangular see-saw-like geometry to four O2- atoms. There are a spread of Bi–O bond distances ranging from 2.18–2.33 Å. There are ten inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Rh+3.29+ and two Pb2+ atoms. In the second O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Rh+3.29+, one Pb2+, and one Bi3+ atom. In the third O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to two equivalent Rh+3.29+, one Pb2+, and one Bi3+ atom. In the fourth O2- site, O2- is bonded in a 3-coordinate geometry to three Rh+3.29+ and one Pb2+ atom. In the fifth O2- site, O2- is bonded in a 3-coordinate geometry to three Rh+3.29+ atoms. In the sixth O2- site, O2- is bonded in a 3-coordinate geometry to three Rh+3.29+ atoms. In the seventh O2- site, O2- is bonded in a distorted rectangular see-saw-like geometry to three Rh+3.29+ and one Bi3+ atom. In the eighth O2- site, O2- is bonded to three Rh+3.29+ and one Pb2+ atom to form distorted corner-sharing ORh3Pb tetrahedra. In the ninth O2- site, O2- is bonded in a 4-coordinate geometry to three Rh+3.29+ and one Pb2+ atom. In the tenth O2- site, O2- is bonded in a 4-coordinate geometry to three Rh+3.29+ and one Pb2+ atom.
CaH12SO9S crystallizes in the triclinic P-1 space group. The structure is one-dimensional and consists of two hydrogen sulfide molecules and two CaH12SO9 ribbons oriented in the (1, 0, 0) direction. In each CaH12SO9 ribbon, Ca2+ is bonded in a 8-coordinate geometry to eight O2- atoms. There are a spread of Ca–O bond distances ranging from 2.40–2.58 Å. There are twelve inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the seventh H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the eighth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the ninth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the tenth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the eleventh H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the twelfth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. S2+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of S–O bond distances ranging from 1.47–1.50 Å. There are nine inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted linear geometry to one Ca2+ and one S2+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to one S2+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to one Ca2+ and one S2+ atom. In the fourth O2- site, O2- is bonded in a water-like geometry to one Ca2+ and two H1+ atoms. In the fifth O2- site, O2- is bonded in a water-like geometry to one Ca2+ and two H1+ atoms. In the sixth O2- site, O2- is bonded in a water-like geometry to one Ca2+ and two H1+ atoms. In the seventh O2- site, O2- is bonded in a distorted water-like geometry to one Ca2+ and two H1+ atoms. In the eighth O2- site, O2- is bonded in a water-like geometry to one Ca2+ and two H1+ atoms. In the ninth O2- site, O2- is bonded in a distorted water-like geometry to one Ca2+ and two H1+ atoms.
KGeCPO7 crystallizes in the monoclinic P2_1 space group. The structure is two-dimensional and consists of one KGeCPO7 sheet oriented in the (0, 0, 1) direction. K1+ is bonded in a 1-coordinate geometry to one O2- atom. The K–O bond length is 2.56 Å. Ge4+ is bonded to six O2- atoms to form GeO6 octahedra that share corners with four equivalent PO4 tetrahedra. There are a spread of Ge–O bond distances ranging from 1.89–1.94 Å. C4+ is bonded in a trigonal planar geometry to three O2- atoms. There is one shorter (1.23 Å) and two longer (1.35 Å) C–O bond length. P5+ is bonded to four O2- atoms to form PO4 tetrahedra that share corners with four equivalent GeO6 octahedra. The corner-sharing octahedra tilt angles range from 30–41°. There are a spread of P–O bond distances ranging from 1.54–1.56 Å. There are seven inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one K1+ and one C4+ atom. In the second O2- site, O2- is bonded in a distorted L-shaped geometry to one Ge4+ and one C4+ atom. In the third O2- site, O2- is bonded in a 2-coordinate geometry to one Ge4+ and one C4+ atom. In the fourth O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ge4+ and one P5+ atom. In the fifth O2- site, O2- is bonded in a 2-coordinate geometry to one Ge4+ and one P5+ atom. In the sixth O2- site, O2- is bonded in a bent 150 degrees geometry to one Ge4+ and one P5+ atom. In the seventh O2- site, O2- is bonded in a distorted bent 150 degrees geometry to one Ge4+ and one P5+ atom.
Ba2PtH8O8 crystallizes in the orthorhombic Pbca space group. The structure is three-dimensional. Ba2+ is bonded in a 8-coordinate geometry to one H1+ and seven O2- atoms. The Ba–H bond length is 2.77 Å. There are a spread of Ba–O bond distances ranging from 2.75–2.93 Å. Pt4+ is bonded in an octahedral geometry to six O2- atoms. There are four shorter (2.04 Å) and two longer (2.05 Å) Pt–O bond lengths. There are four inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 1.00 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.98 Å. In the third H1+ site, H1+ is bonded in a single-bond geometry to one Ba2+ and one O2- atom. The H–O bond length is 1.00 Å. In the fourth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Ba2+, one Pt4+, and one H1+ atom. In the second O2- site, O2- is bonded in a single-bond geometry to two equivalent Ba2+ and one H1+ atom. In the third O2- site, O2- is bonded in a distorted single-bond geometry to one Ba2+, one Pt4+, and one H1+ atom. In the fourth O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent Ba2+, one Pt4+, and one H1+ atom.
KPH3O4 crystallizes in the monoclinic P2_1/c space group. The structure is three-dimensional. there are two inequivalent K1+ sites. In the first K1+ site, K1+ is bonded in a 5-coordinate geometry to one H1+ and seven O2- atoms. The K–H bond length is 2.81 Å. There are a spread of K–O bond distances ranging from 2.82–3.06 Å. In the second K1+ site, K1+ is bonded in a 8-coordinate geometry to one H1+ and seven O2- atoms. The K–H bond length is 2.86 Å. There are a spread of K–O bond distances ranging from 2.82–3.00 Å. There are two inequivalent P4+ sites. In the first P4+ site, P4+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There is two shorter (1.53 Å) and one longer (1.59 Å) P–O bond length. In the second P4+ site, P4+ is bonded in a trigonal non-coplanar geometry to three O2- atoms. There are a spread of P–O bond distances ranging from 1.52–1.62 Å. There are six inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one K1+ and one O2- atom. The H–O bond length is 0.99 Å. In the second H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. In the third H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.05 Å) and one longer (1.47 Å) H–O bond length. In the fourth H1+ site, H1+ is bonded in a linear geometry to two O2- atoms. There is one shorter (1.03 Å) and one longer (1.56 Å) H–O bond length. In the fifth H1+ site, H1+ is bonded in a single-bond geometry to one K1+ and one O2- atom. The H–O bond length is 1.00 Å. In the sixth H1+ site, H1+ is bonded in a single-bond geometry to one O2- atom. The H–O bond length is 0.99 Å. There are eight inequivalent O2- sites. In the first O2- site, O2- is bonded in a water-like geometry to two equivalent K1+ and two H1+ atoms. In the second O2- site, O2- is bonded in a water-like geometry to two equivalent K1+ and two H1+ atoms. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to two equivalent K1+, one P4+, and one H1+ atom. In the fourth O2- site, O2- is bonded in a single-bond geometry to one K1+ and one P4+ atom. In the fifth O2- site, O2- is bonded in a distorted water-like geometry to two K1+, one P4+, and one H1+ atom. In the sixth O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one K1+, one P4+, and one H1+ atom. In the seventh O2- site, O2- is bonded in a distorted single-bond geometry to two equivalent K1+ and one P4+ atom. In the eighth O2- site, O2- is bonded in a 2-coordinate geometry to two equivalent K1+, one P4+, and one H1+ atom.