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All sourcesNASA NTRSDOE OSTI
DOE OSTI2020

Hall effect for Dirac electrons in graphene exposed to an Abrikosov flux lattice

The proposals for realizing exotic particles through coupling of quantum Hall effect to superconductivity involve spatially non-uniform magnetic fields. As a step toward that goal, we study, both theoretically and experimentally, a system of Dirac electrons exposed to an Abrikosov flux lattice. Here, we theoretically find that the non-uniform magnetic field causes a carrier-density-dependent reduction of the Hall conductivity. Our studies show that this reduction originates from a rather subtle effect: a levitation of the Berry curvature within Landau levels broadened by the non-uniform magnetic field. Experimentally, we measure the magneto-transport in a monolayer graphene-hexagonal boron nitride-niobium diselenide (NbSe 2 ) heterostructure, and find a density-dependent reduction of the Hall resistivity of graphene as the temperature is lowered from above the superconducting critical temperature of NbSe 2 , when the magnetic field is uniform, to below, where the magnetic field bunches into an Abrikosov flux lattice.

75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND↗
DOE OSTI2023

NbTaV_BCC_SolidSolution_128atoms_VASP6

We performed density functional theory (DFT) calculations for body-centered-cubic (BCC) structures with 128 lattices sites of solid solution ternary alloys niobium-tantalum-vanadium (Nb-Ta-V). The first-principle code that has been used to run the calculations is the closed-source Vienna Ab-Initio Simulation Package (VASP). The calculations have been collected by sampling chemical compositions across the entire compositional range. The chemical compositions have been sampled by progressively changing the number of atoms per constituent by 8. For each chemical composition of binaries and ternaries, the first-principle calculations have been run for 100 randomized arrangements of the constituents on the BCC lattice sites. We collected data for a total of 10,500 randomized atomic structures over 105 chemical compositions. The calculations have been collected on NERSC-Perlmutter using the VASP 6.3.2. The VASP calculations for every atomic structure have been performed in 2 main steps: 1. Starting from an ideal body-centered-cubic (BCC) structure, geometry optimization with low precision has been executed to perform a preliminary optimization of the atomic structure. The output for this calculations is available in the files 0.CONTCAR, 0.OUTCAR, rlx1.out. 2. Using the atomic structure resulting from the preliminary geometry optimization, a second geometry optimization has been performed using normal precision. The output for this calculations is available in the files CONTCAR, OUTCAR, rlx2.out, vaspout.h5, and vasprun.xml. Every chemical composition sampled across the composition range in the dataset has its own directory. The convention used to name the directories for ternary alloys is AXBYCZ, where A, B, and C refer to the constituents, and X, Y, and Z are positive integers that represent the number of atoms for each constituent and their values still sum up to 128. Each atomic structure associated with a specific chemical composition has its own sub-directory within the directory of the corresponding chemical composition. The sub-directories for each atomic structure for each chemical composition are named 'case-*', where * is a positive integer that spans all the values from 1 through 100, extremes included. The files contained in each sub-directory 'case-*' for each atomic structure are as follows: 1. INCAR: input file that contains various parameters and settings for controlling the behavior of the electronic structure calculations 2. 0.POSCAR: input file that defines the atomic structure of a system 3. 0.CONTCAR: output file that provides the atomic positions and cell parameters after the first geometry optimization has been run with the precision variable set to PREC=Low in the INCAR file 4. 0.OUTCAR: output file that contains detailed information about the progress of a calculation after the first geometry optimization has been run with the precision variable set to PREC=Low in the INCAR file 5. rlx1.out: file with diagnostic information about the execution of the first geometry optimization with precision variable set to PREC=Low in the INCAR file 6. POSCAR: input file that defines the atomic structure of a system after the first geometry optimization has been run at low precision. This represents the input for the second geometry optimization run with the precision variable set to PREC=Normal in the INCAR file 7. CONTCAR: output file that provides the atomic positions and cell parameters after the second geometry optimization has been run with the precision variable set to PREC=Normal in the INCAR file 8. OUTCARL: output file that contains detailed information about the progress of a calculation after the second geometry optimization has been run with the precision variable set to PREC=Normal in the INCAR file 9. rlx2.out: file with diagnostic information about the execution of the second geometry optimization with precision variable set to PREC=Normal in the INCAR file 10. vaspout.h5: hierarchical HDF5 file containing the inputs and outputs of a VASP calculation. To analyze the data in this file we recommend using py4vasp. This file is only produced if the VASP version used is compiled with HDF5 support 11. vasprun.xml: contains similar information to OUTCAR, but in an xml format. This research is sponsored by the Artificial Intelligence Initiative as part of the Laboratory Directed Research and Development (LDRD) Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the US Department of Energy under contract DE-AC05-00OR22725. This work used resources of the Oak Ridge Leadership Computing Facility, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC05-00OR22725, under Directorate Discretionary awards MAT025 (Materials Science) and LRN026 (Machine Learning), and INCITE award MAT201. This work also used resources of the National Energy Research Scientific Computing Center, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231, under award ERCAP0025216.

36 MATERIALS SCIENCE↗
DOE OSTI2023

NbTa_BCC_SolidSolution_128atoms_VASP6

We performed density functional theory (DFT) calculations for body-centered-cubic (BCC) structures with 128 lattices sites of solid solution binary alloys niobium-tantalum (Nb-Ta). The electronic structures of alloys have been calculated using Vienna Ab initio Simulation Package (VASP). Within this package the DFT approach is used to reduce many-body Schrodinger equation to set of single particle Kohn-Sham (KS) equations. The generalized electronic exchange-correlation functional is described by generalized gradient approximation with the Perdew-Burke-Ernzerhof parametrization. The electron-ion interactions is described by pseudopotentials developed within the plane-wave basis projector augmented-wave (PAW) approach \cite{PAW}. These pseudopotentials are available at the VASP portal (http://cms.mpi.univie.ac.at/vasp/). Our calculations have been run with the pseudopotentials treating s and p semi-core states as valence in case for the elements Nb. For Ta, p semi-core states as valence were chosen. The electronic densities and potentials are expanded over plane-waves with energy cutoff of 350 eV. 2x2x2 k-mesh and normal precision were used. The alloys were modeled by supercell containing 128 randomly distributed atoms. At initial step the atoms occupy perfect bcc lattice cites. This initial structure was optimized until energy changes less than 1e-6 eV, while forces acting on atoms don't exceed 1e-2 eV/angstrom. The electron-ion interaction is described by PAW pseudopotentials. The calculations have been collected by sampling chemical compositions across the entire compositional range. The chemical compositions have been sampled by progressively changing the number of atoms per constituent by 4. For each chemical composition of binaries and ternaries, the first-principle calculations have been run for 100 randomized arrangements of the constituents on the BCC lattice sites. We collected data for a total of 3,100 randomized atomic structures over 31 chemical compositions. The calculations have been collected on NERSC-Perlmutter using the VASP 6.3.2. The VASP calculations for every atomic structure have been performed in 2 main steps: 1. Starting from an ideal body-centered-cubic (BCC) structure, geometry optimization with low precision has been executed to perform a preliminary optimization of the atomic structure. The output for this calculations is available in the files 0.CONTCAR, 0.OUTCAR, rlx1.out. 2. Using the atomic structure resulting from the preliminary geometry optimization, a second geometry optimization has been performed using normal precision. The output for this calculations is available in the files CONTCAR, OUTCAR, rlx2.out, vaspout.h5, and vasprun.xml. Cases 1-10 have been run without generating the file 'vaspout.h5'. Every chemical composition sampled across the composition range in the dataset has its own directory. The convention used to name the directories for ternary alloys is AXBYCZ, where A, B, and C refer to the constituents, and X, Y, and Z are positive integers that represent the number of atoms for each constituent and their values still sum up to 128. Each atomic structure associated with a specific chemical composition has its own sub-directory within the directory of the corresponding chemical composition. The sub-directories for each atomic structure for each chemical composition are named 'case-*', where * is a positive integer that spans all the values from 1 through 100, extremes included. The files contained in each sub-directory 'case-*' for each atomic structure are as follows: FILES contained in each subdirectory with name case-N where N ranges between 11 and 100, extremes included: 1. INCAR: input file that contains various parameters and settings for controlling the behavior of the electronic structure calculations 2. KPOINTS: input file that specifies the Bloch vectors (k points) used to sample the Brillouin zone 3. 0.POSCAR: input file that defines the atomic structure of a system 4. 0.CONTCAR: output file that provides the atomic positions and cell parameters after the first geometry optimization has been run with the precision variable set to PREC=Low in the INCAR file 5. 0.OUTCAR: output file that contains detailed information about the progress of a calculation after the first geometry optimization has been run with the precision variable set to PREC=Low in the INCAR file 6. rlx1.out: file with diagnostic information about the execution of the first geometry optimization with precision variable set to PREC=Low in the INCAR file 7. POSCAR: input file that defines the atomic structure of a system after the first geometry optimization has been run at low precision. This represents the input for the second geometry optimization run with the precision variable set to PREC=Normal in the INCAR file 8. CONTCAR: output file that provides the atomic positions and cell parameters after the second geometry optimization has been run with the precision variable set to PREC=Normal in the INCAR file 9. OUTCAR: output file that contains detailed information about the progress of a calculation after the second geometry optimization has been run with the precision variable set to PREC=Normal in the INCAR file 10. rlx2.out: file with diagnostic information about the execution of the second geometry optimization with precision variable set to PREC=Normal in the INCAR file 11. vaspout.h5: hierarchical HDF5 file containing the inputs and outputs of a VASP calculation. To analyze the data in this file we recommend using py4vasp. This file is only produced if the VASP version used is compiled with HDF5 support 12. vasprun.xml: contains similar information to OUTCAR, but in an xml format. Subdirectories with name case-N, where N ranges between 1 and 10 (extremes included) contain all the files listed above except 'vaspout.h5'. Subdirectories with name case-N, where N ranges between 41 and 60 (extremes included), contain a duplicate copy of the files listed above except for KPOINTS. The names of the duplicate files end with -bis, and correspond to a second VASP calculation that has converged to a different optimized geometry. This research is sponsored by the Artificial Intelligence Initiative as part of the Laboratory Directed Research and Development (LDRD) Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the US Department of Energy under contract DE-AC05-00OR22725. This work used resources of the Oak Ridge Leadership Computing Facility, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC05-00OR22725, under Directorate Discretionary awards MAT025 (Materials Science) and LRN026 (Machine Learning), and INCITE award MAT201. This work also used resources of the National Energy Research Scientific Computing Center, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231, under award ERCAP0025216. REFERENCES (1) Kresse, G. and Hafner, J. Ab initio molecular dynamics for liquid metals. Phys. review B 47, 558 (1993). (2) Kresse, G. and Hafner, J. Ab initio molecular-dynamics simulation of the liquid-metal-amorphous-semiconductor transition in germanium. Phys. Rev. B 49, 14251 (1994) (3) Kresse, G. and Furthmüller, J. Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set. Comput. materials science 6, 15-50 (1996) (4) Kresse, G. and Furthmüller, J. Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. Phys. review B 54, 11169 (1996) (5) Kresse, G. and Joubert, D. From ultrasoft pseudopotentials to the projector augmented-wave method. Phys. review b 59, 1758 (1999)

36 MATERIALS SCIENCE↗
DOE OSTI2023

NbV_BCC_SolidSolution_128atoms_VASP6

We performed density functional theory (DFT) calculations for body-centered-cubic (BCC) structures with 128 lattices sites of solid solution binary alloys niobium-vanadium (Nb-V). The electronic structures of alloys have been calculated using Vienna Ab initio Simulation Package (VASP). Within this package the DFT approach is used to reduce many-body Schrodinger equation to set of single particle Kohn-Sham (KS) equations. The generalized electronic exchange-correlation functional is described by generalized gradient approximation with the Perdew-Burke-Ernzerhof parametrization. The electron-ion interactions is described by pseudopotentials developed within the plane-wave basis projector augmented-wave (PAW) approach \cite{PAW}. These pseudopotentials are available at the VASP portal (http://cms.mpi.univie.ac.at/vasp/). Our calculations have been run with the pseudopotentials treating s and p semi-core states as valence in case for the elements Nb and V. The electronic densities and potentials are expanded over plane-waves with energy cutoff of 350 eV. 2x2x2 k-mesh and normal precision were used. The alloys were modeled by supercell containing 128 randomly distributed atoms. At initial step the atoms occupy perfect bcc lattice cites. This initial structure was optimized until energy changes less than 1e-6 eV, while forces acting on atoms don't exceed 1e-2 eV/angstrom. The electron-ion interaction is described by PAW pseudopotentials. The calculations have been collected by sampling chemical compositions across the entire compositional range. The chemical compositions have been sampled by progressively changing the number of atoms per constituent by 4. For each chemical composition of binaries and ternaries, the first-principle calculations have been run for 100 randomized arrangements of the constituents on the BCC lattice sites. We collected data for a total of 3,100 randomized atomic structures over 31 chemical compositions. The calculations have been collected on NERSC-Perlmutter and OLCF-Summit using the VASP 6.3.2. The VASP calculations for every atomic structure have been performed in 2 main steps: 1. Starting from an ideal body-centered-cubic (BCC) structure, geometry optimization with low precision has been executed to perform a preliminary optimization of the atomic structure. The output for this calculations is available in the files 0.CONTCAR, 0.OUTCAR, rlx1.out. 2. Using the atomic structure resulting from the preliminary geometry optimization, a second geometry optimization has been performed using normal precision. The output for this calculations is available in the files CONTCAR, OUTCAR, rlx2.out, vaspout.h5, and vasprun.xml. Cases 1-10 have been run without generating the file 'vaspout.h5'. Every chemical composition sampled across the composition range in the dataset has its own directory. The convention used to name the directories for binary alloys is AXBY, where A and B refer to the constituents, whereas X and Y are positive integers that represent the number of atoms for each constituent and their values still sum up to 128. Each atomic structure associated with a specific chemical composition has its own sub-directory within the directory of the corresponding chemical composition. The sub-directories for each atomic structure for each chemical composition are named 'case-*', where * is a positive integer that spans all the values from 1 through 100, extremes included. The files contained in each sub-directory 'case-*' for each atomic structure are as follows: FILES contained in each subdirectory with name case-N where N ranges between 11 and 100, extremes included: 1. INCAR: input file that contains various parameters and settings for controlling the behavior of the electronic structure calculations 2. KPOINTS: input file that specifies the Bloch vectors (k points) used to sample the Brillouin zone 3. 0.POSCAR: input file that defines the atomic structure of a system 4. 0.CONTCAR: output file that provides the atomic positions and cell parameters after the first geometry optimization has been run with the precision variable set to PREC=Low in the INCAR file 5. 0.OUTCAR: output file that contains detailed information about the progress of a calculation after the first geometry optimization has been run with the precision variable set to PREC=Low in the INCAR file 6. rlx1.out: file with diagnostic information about the execution of the first geometry optimization with precision variable set to PREC=Low in the INCAR file 7. POSCAR: input file that defines the atomic structure of a system after the first geometry optimization has been run at low precision. This represents the input for the second geometry optimization run with the precision variable set to PREC=Normal in the INCAR file 8. CONTCAR: output file that provides the atomic positions and cell parameters after the second geometry optimization has been run with the precision variable set to PREC=Normal in the INCAR file 9. OUTCAR: output file that contains detailed information about the progress of a calculation after the second geometry optimization has been run with the precision variable set to PREC=Normal in the INCAR file 10. rlx2.out: file with diagnostic information about the execution of the second geometry optimization with precision variable set to PREC=Normal in the INCAR file 11. vaspout.h5: hierarchical HDF5 file containing the inputs and outputs of a VASP calculation. To analyze the data in this file we recommend using py4vasp. This file is only produced if the VASP version used is compiled with HDF5 support 12. vasprun.xml: contains similar information to OUTCAR, but in an xml format. Subdirectories with name case-N, where N ranges between 1 and 10 (extremes included) contain all the files listed above except 'vaspout.h5'. Subdirectories with name case-N, where N ranges between 41 and 60 (extremes included), contain a duplicate copy of the files listed above except for KPOINTS. The names of the duplicate files end with -bis, and correspond to a second VASP calculation that has converged to a different optimized geometry. This research is sponsored by the Artificial Intelligence Initiative as part of the Laboratory Directed Research and Development (LDRD) Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the US Department of Energy under contract DE-AC05-00OR22725. This work used resources of the Oak Ridge Leadership Computing Facility, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC05-00OR22725, under Directorate Discretionary awards MAT025 (Materials Science) and LRN026 (Machine Learning), and INCITE award MAT201. This work also used resources of the National Energy Research Scientific Computing Center, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231, under award ERCAP0025216. REFERENCES (1) Kresse, G. and Hafner, J. Ab initio molecular dynamics for liquid metals. Phys. review B 47, 558 (1993). (2) Kresse, G. and Hafner, J. Ab initio molecular-dynamics simulation of the liquid-metal-amorphous-semiconductor transition in germanium. Phys. Rev. B 49, 14251 (1994) (3) Kresse, G. and Furthmüller, J. Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set. Comput. materials science 6, 15-50 (1996) (4) Kresse, G. and Furthmüller, J. Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. Phys. review B 54, 11169 (1996) (5) Kresse, G. and Joubert, D. From ultrasoft pseudopotentials to the projector augmented-wave method. Phys. review b 59, 1758 (1999)

36 MATERIALS SCIENCE↗
DOE OSTI2024

NbZr_BCC_SolidSolution_128atoms_VASP6

We performed density functional theory (DFT) calculations for body-centered-cubic (BCC) structures with 128 lattices sites of solid solution binary alloys niobium-zirconium (Nb-Zr). The electronic structures of alloys have been calculated using Vienna Ab initio Simulation Package (VASP). Within this package the DFT approach is used to reduce many-body Schrodinger equation to set of single particle Kohn-Sham (KS) equations. The generalized electronic exchange-correlation functional is described by generalized gradient approximation with the Perdew-Burke-Ernzerhof parametrization. The electron-ion interactions is described by pseudopotentials developed within the plane-wave basis projector augmented-wave (PAW) approach \cite{PAW}. These pseudopotentials are available at the VASP portal (http://cms.mpi.univie.ac.at/vasp/). Our calculations have been run with the pseudopotentials treating s and p semi-core states as valence in case for the elements Nb and Zr. The electronic densities and potentials are expanded over plane-waves with energy cutoff of 350 eV. 2x2x2 k-mesh and normal precision were used. The alloys were modeled by supercell containing 128 randomly distributed atoms. At initial step the atoms occupy perfect bcc lattice cites. This initial structure was optimized until energy changes less than 1e-6 eV, while forces acting on atoms don't exceed 1e-2 eV/angstrom. The electron-ion interaction is described by PAW pseudopotentials. The calculations have been collected by sampling chemical compositions across the entire compositional range. The chemical compositions have been sampled by progressively changing the number of atoms per constituent by 4. For each chemical composition of binaries and ternaries, the first-principle calculations have been run for 100 randomized arrangements of the constituents on the BCC lattice sites. We collected data for a total of 3,100 randomized atomic structures over 31 chemical compositions. The calculations have been collected on NERSC-Perlmutter and OLCF-Summit using the VASP 6.3.2. The VASP calculations for every atomic structure have been performed in 2 main steps: 1. Starting from an ideal body-centered-cubic (BCC) structure, geometry optimization with low precision has been executed to perform a preliminary optimization of the atomic structure. The output for this calculations is available in the files 0.CONTCAR, 0.OUTCAR, rlx1.out. 2. Using the atomic structure resulting from the preliminary geometry optimization, a second geometry optimization has been performed using normal precision. The output for this calculations is available in the files CONTCAR, OUTCAR, rlx2.out, vaspout.h5, and vasprun.xml. Cases 1-10 have been run without generating the file 'vaspout.h5'. Every chemical composition sampled across the composition range in the dataset has its own directory. The convention used to name the directories for binary alloys is AXBY, where A and B refer to the constituents, whereas X and Y are positive integers that represent the number of atoms for each constituent and their values still sum up to 128. Each atomic structure associated with a specific chemical composition has its own sub-directory within the directory of the corresponding chemical composition. The sub-directories for each atomic structure for each chemical composition are named 'case-*', where * is a positive integer that spans all the values from 1 through 100, extremes included. The files contained in each sub-directory 'case-*' for each atomic structure are as follows: FILES contained in each subdirectory with name "case-N" where N ranges between 11 and 100, extremes included: 1. INCAR: input file that contains various parameters and settings for controlling the behavior of the electronic structure calculations 2. KPOINTS: input file that specifies the Bloch vectors (k points) used to sample the Brillouin zone 3. 0.POSCAR: input file that defines the atomic structure of a system 4. 0.CONTCAR: output file that provides the atomic positions and cell parameters after the first geometry optimization has been run with the precision variable set to PREC=Low in the INCAR file 5. 0.OUTCAR: output file that contains detailed information about the progress of a calculation after the first geometry optimization has been run with the precision variable set to PREC=Low in the INCAR file 6. rlx1.out: file with diagnostic information about the execution of the first geometry optimization with precision variable set to PREC=Low in the INCAR file 7. POSCAR: input file that defines the atomic structure of a system after the first geometry optimization has been run at low precision. This represents the input for the second geometry optimization run with the precision variable set to PREC=Normal in the INCAR file 8. CONTCAR: output file that provides the atomic positions and cell parameters after the second geometry optimization has been run with the precision variable set to PREC=Normal in the INCAR file 9. OUTCAR: output file that contains detailed information about the progress of a calculation after the second geometry optimization has been run with the precision variable set to PREC=Normal in the INCAR file 10. rlx2.out: file with diagnostic information about the execution of the second geometry optimization with precision variable set to PREC=Normal in the INCAR file 11. vaspout.h5: hierarchical HDF5 file containing the inputs and outputs of a VASP calculation. To analyze the data in this file we recommend using py4vasp. This file is only produced if the VASP version used is compiled with HDF5 support 12. vasprun.xml: contains similar information to OUTCAR, but in an xml format. 13. CHGCAR: contains the charge density data of a system. This data is crucial for analyzing electronic structures, calculating electrostatic potential, and studying the distribution of charge in a crystal or molecular system FILES contained in each subdirectory with name "case-N" where N ranges between 1 and 10, extremes included: 1. INCAR: input file that contains various parameters and settings for controlling the behavior of the electronic structure calculations 2. KPOINTS: input file that specifies the Bloch vectors (k points) used to sample the Brillouin zone 3. {ID}.POSCAR: input file that defines the atomic structure of a system at the beginning of ID execution of geometry optimization with PREC=LOW 4. {ID}.CONTCAR: output file that provides the atomic positions and cell parameters at the end of ID execution of geometry optimization with PREC=LOW in the INCAR file 5. {ID}.OUTCAR: output file that contains detailed information about the progress of a calculation after the ID execution of geometry optimization that has been run with the precision variable set to PREC=Low in the INCAR file 6. rlx1.{ID}.out: file with diagnostic information about the execution of the ID execution of the geometry optimization with precision variable set to PREC=Low in the INCAR file 7. N{ID}.POSCAR: input file that defines the atomic structure of a system after the geometry optimization run at low precision. This represents the input for the ID execution of the second geometry optimization run with the precision variable set to PREC=Normal in the INCAR file 8. N{ID}.CONTCAR: output file that provides the atomic positions and cell parameters after the ID execution of the geometry optimization run with the precision variable set to PREC=Normal in the INCAR file 9. N{ID}.OUTCAR: output file that contains detailed information about the progress of a calculation after the ID execution of the geometry optimization run with the precision variable set to PREC=Normal in the INCAR file 10. rlx2.{ID}.out: file with diagnostic information about the ID execution of geometry optimization with precision variable set to PREC=Normal in the INCAR file 11. vaspout.h5: hierarchical HDF5 file containing the inputs and outputs of a VASP calculation. To analyze the data in this file we recommend using py4vasp. This file is only produced if the VASP version used is compiled with HDF5 support 12. vasprun.xml: contains similar information to OUTCAR, but in an xml format. 13. CHGCAR: contains the charge density data of a system. This data is crucial for analyzing electronic structures, calculating electrostatic potential, and studying the distribution of charge in a crystal or molecular system This research is sponsored by the Artificial Intelligence Initiative as part of the Laboratory Directed Research and Development (LDRD) Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC, for the US Department of Energy under contract DE-AC05-00OR22725. This work used resources of the Oak Ridge Leadership Computing Facility, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC05-00OR22725, under Directorate Discretionary awards MAT025 (Materials Science) and LRN026 (Machine Learning), and INCITE award MAT201. This work also used resources of the National Energy Research Scientific Computing Center, which is supported by the Office of Science of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231, under award ERCAP0025216. REFERENCES (1) Kresse, G. & Hafner, J. Ab initio molecular dynamics for liquid metals. Phys. review B 47, 558 (1993). (2) Kresse, G. & Hafner, J. Ab initio molecular-dynamics simulation of the liquid-metal–amorphous-semiconductor transition in germanium. Phys. Rev. B 49, 14251 (1994) (3) Kresse, G. & Furthmüller, J. Efficiency of ab-initio total energy calculations for metals and semiconductors using a plane-wave basis set. Comput. materials science 6, 15–50 (1996) (4) Kresse, G. & Furthmüller, J. Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set. Phys. review B 54, 11169 (1996) (5) Kresse, G. & Joubert, D. From ultrasoft pseudopotentials to the projector augmented-wave method. Phys. review b 59, 1758 (1999)

36 MATERIALS SCIENCE↗
DOE OSTI2025

HfNb_BCC_SolidSolution_128atoms_VASP6

We performed density functional theory (DFT) calculations for body-centered-cubic (BCC) structures with 128 lattices sites of solid solution binary alloys hafnium-niobium (Hf-Nb). The electronic structures of alloys have been calculated using Vienna Ab initio Simulation Package (VASP). Within this package the DFT approach is used to reduce many-body Schrodinger equation to set of single particle Kohn-Sham (KS) equations. The generalized electronic exchange-correlation functional is described by generalized gradient approximation with the Perdew-Burke-Ernzerhof parametrization. The electron-ion interactions is described by pseudopotentials developed within the plane-wave basis projector augmented-wave (PAW) approach. These pseudopotentials are available at the VASP portal (http://cms.mpi.univie.ac.at/vasp/). Our calculations have been run with the pseudopotentials treating s and p semi-core states as valence in case for the elements Hf and Nb. The electronic densities and potentials are expanded over plane-waves with energy cutoff of 350 eV. 2x2x2 k-mesh and normal precision were used. The alloys were modeled by supercell containing 128 randomly distributed atoms. At initial step the atoms occupy perfect BCC lattice cites. This initial structure was optimized until energy changes less than 1e-6 eV, while forces acting on atoms don't exceed 1e-2 eV/angstrom. The electron-ion interaction is described by PAW pseudopotentials. The calculations have been collected by sampling chemical compositions across the entire compositional range. The chemical compositions have been sampled by progressively changing the number of atoms per constituent by 4. For each chemical composition of binaries and ternaries, the first-principle calculations have been run for 100 randomized arrangements of the constituents on the BCC lattice sites. We collected data for a total of 3,029 randomized atomic structures over 31 chemical compositions. Further methodological and structural information is contained in the dataset README.txt file.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on TaP by Materials Project

TaP is alpha Niobium phosphide structured and crystallizes in the tetragonal I4_1/amd space group. The structure is two-dimensional and consists of four TaP sheets oriented in the (0, 0, 1) direction. Ta3+ is bonded in a square co-planar geometry to four equivalent P3- atoms. All Ta–P bond lengths are 2.48 Å. P3- is bonded in a square co-planar geometry to four equivalent Ta3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on TaAs by Materials Project

TaAs is alpha Niobium phosphide structured and crystallizes in the tetragonal I4_1md space group. The structure is three-dimensional. Ta3+ is bonded to six equivalent As3- atoms to form a mixture of distorted face, edge, and corner-sharing TaAs6 pentagonal pyramids. There are two shorter (2.62 Å) and four longer (2.64 Å) Ta–As bond lengths. As3- is bonded to six equivalent Ta3+ atoms to form a mixture of distorted face, edge, and corner-sharing AsTa6 pentagonal pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on NbAs by Materials Project

NbAs is alpha Niobium phosphide structured and crystallizes in the tetragonal I4_1md space group. The structure is three-dimensional. Nb3+ is bonded to six equivalent As3- atoms to form a mixture of distorted corner, edge, and face-sharing NbAs6 pentagonal pyramids. All Nb–As bond lengths are 2.64 Å. As3- is bonded to six equivalent Nb3+ atoms to form a mixture of distorted corner, edge, and face-sharing AsNb6 pentagonal pyramids.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SbI3Cl8 by Materials Project

Sb(ICl4)2I is alpha Niobium phosphide-like structured and crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of one hydriodic acid molecule and one Sb(ICl4)2 cluster. In the Sb(ICl4)2 cluster, Sb5+ is bonded in an octahedral geometry to six Cl1- atoms. There are a spread of Sb–Cl bond distances ranging from 2.38–2.51 Å. I1+ is bonded in a linear geometry to two Cl1- atoms. There are one shorter (2.39 Å) and one longer (2.82 Å) I–Cl bond lengths. There are four inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a single-bond geometry to one Sb5+ atom. In the second Cl1- site, Cl1- is bonded in a single-bond geometry to one I1+ atom. In the third Cl1- site, Cl1- is bonded in a distorted bent 120 degrees geometry to one Sb5+ and one I1+ atom. In the fourth Cl1- site, Cl1- is bonded in a single-bond geometry to one Sb5+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ICl3 by Materials Project

ICl3 is alpha Niobium phosphide-derived structured and crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of one ICl3 cluster. I is bonded in a rectangular see-saw-like geometry to four Cl atoms. There are a spread of I–Cl bond distances ranging from 2.39–2.74 Å. There are three inequivalent Cl sites. In the first Cl site, Cl is bonded in a single-bond geometry to one I atom. In the second Cl site, Cl is bonded in an L-shaped geometry to two equivalent I atoms. In the third Cl site, Cl is bonded in a single-bond geometry to one I atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on AsXeF7 by Materials Project

XeAsF7 is alpha Niobium phosphide-derived structured and crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of four XeAsF7 clusters. Xe is bonded in a linear geometry to two F atoms. There are one shorter (2.00 Å) and one longer (2.22 Å) Xe–F bond lengths. As is bonded in an octahedral geometry to six F atoms. There are a spread of As–F bond distances ranging from 1.74–1.97 Å. There are seven inequivalent F sites. In the first F site, F is bonded in a single-bond geometry to one As atom. In the second F site, F is bonded in a single-bond geometry to one Xe atom. In the third F site, F is bonded in a bent 120 degrees geometry to one Xe and one As atom. In the fourth F site, F is bonded in a single-bond geometry to one As atom. In the fifth F site, F is bonded in a single-bond geometry to one As atom. In the sixth F site, F is bonded in a single-bond geometry to one As atom. In the seventh F site, F is bonded in a single-bond geometry to one As atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on I2(OF2)3 by Materials Project

I2(OF2)3 is alpha Niobium phosphide-derived structured and crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of two I2(OF2)3 clusters. there are three inequivalent O sites. In the first O site, O is bonded in a distorted bent 120 degrees geometry to two I atoms. There are one shorter (1.82 Å) and one longer (2.32 Å) O–I bond lengths. In the second O site, O is bonded in a distorted bent 120 degrees geometry to two I atoms. There are one shorter (1.83 Å) and one longer (2.28 Å) O–I bond lengths. In the third O site, O is bonded in a single-bond geometry to one I atom. The O–I bond length is 1.76 Å. There are two inequivalent I sites. In the first I site, I is bonded to three O and two F atoms to form distorted corner-sharing IO3F2 square pyramids. The corner-sharing octahedral tilt angles are 47°. There is one shorter (1.90 Å) and one longer (1.91 Å) I–F bond length. In the second I site, I is bonded to two O and four F atoms to form corner-sharing IO2F4 octahedra. There is one shorter (1.87 Å) and three longer (1.88 Å) I–F bond length. There are six inequivalent F sites. In the first F site, F is bonded in a single-bond geometry to one I atom. In the second F site, F is bonded in a single-bond geometry to one I atom. In the third F site, F is bonded in a single-bond geometry to one I atom. In the fourth F site, F is bonded in a single-bond geometry to one I atom. In the fifth F site, F is bonded in a single-bond geometry to one I atom. In the sixth F site, F is bonded in a single-bond geometry to one I atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Nb7(BC)4 by Materials Project

Nb(Nb3C2)2(B)4 crystallizes in the orthorhombic Immm space group. The structure is two-dimensional and consists of two niobium molecules; two B ribbons oriented in the (1, 0, 0) direction; and two Nb3C2 sheets oriented in the (0, 0, 1) direction. In each B ribbon, there are two inequivalent B sites. In the first B site, B is bonded in a 3-coordinate geometry to three B atoms. There is two shorter (1.83 Å) and one longer (1.85 Å) B–B bond length. In the second B site, B is bonded in a 2-coordinate geometry to two equivalent B atoms. In each Nb3C2 sheet, there are three inequivalent Nb+2.29+ sites. In the first Nb+2.29+ site, Nb+2.29+ is bonded in a single-bond geometry to one C4- atom. The Nb–C bond length is 2.14 Å. In the second Nb+2.29+ site, Nb+2.29+ is bonded to six C4- atoms to form NbC6 octahedra that share corners with four equivalent NbC6 octahedra, a cornercorner with one NbC5 square pyramid, edges with eight equivalent NbC6 octahedra, and edges with four equivalent NbC5 square pyramids. The corner-sharing octahedral tilt angles are 2°. There are a spread of Nb–C bond distances ranging from 2.19–2.29 Å. In the third Nb+2.29+ site, Nb+2.29+ is bonded to five C4- atoms to form NbC5 square pyramids that share a cornercorner with one NbC6 octahedra, corners with four equivalent NbC5 square pyramids, edges with four equivalent NbC6 octahedra, and edges with four equivalent NbC5 square pyramids. The corner-sharing octahedral tilt angles are 0°. There are one shorter (2.20 Å) and four longer (2.26 Å) Nb–C bond lengths. There are two inequivalent C4- sites. In the first C4- site, C4- is bonded to six Nb+2.29+ atoms to form a mixture of edge and corner-sharing CNb6 octahedra. The corner-sharing octahedra tilt angles range from 0–2°. In the second C4- site, C4- is bonded to six Nb+2.29+ atoms to form a mixture of edge and corner-sharing CNb6 octahedra. The corner-sharing octahedra tilt angles range from 0–1°.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ZrI4 by Materials Project

ZrI4 is alpha Niobium phosphide-derived structured and crystallizes in the triclinic P-1 space group. The structure is zero-dimensional and consists of one ZrI4 cluster. there are two inequivalent Zr4+ sites. In the first Zr4+ site, Zr4+ is bonded to six I1- atoms to form ZrI6 octahedra that share an edgeedge with one ZrI6 octahedra and an edgeedge with one ZrI5 trigonal bipyramid. There are a spread of Zr–I bond distances ranging from 2.73–3.08 Å. In the second Zr4+ site, Zr4+ is bonded to five I1- atoms to form edge-sharing ZrI5 trigonal bipyramids. There are a spread of Zr–I bond distances ranging from 2.71–3.07 Å. There are eight inequivalent I1- sites. In the first I1- site, I1- is bonded in a water-like geometry to two equivalent Zr4+ atoms. In the second I1- site, I1- is bonded in a water-like geometry to two Zr4+ atoms. In the third I1- site, I1- is bonded in a water-like geometry to two Zr4+ atoms. In the fourth I1- site, I1- is bonded in a single-bond geometry to one Zr4+ atom. In the fifth I1- site, I1- is bonded in a single-bond geometry to one Zr4+ atom. In the sixth I1- site, I1- is bonded in a single-bond geometry to one Zr4+ atom. In the seventh I1- site, I1- is bonded in a single-bond geometry to one Zr4+ atom. In the eighth I1- site, I1- is bonded in a single-bond geometry to one Zr4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on HoS by Materials Project

HoS is alpha Niobium phosphide-like structured and crystallizes in the monoclinic C2/m space group. The structure is two-dimensional and consists of two HoS sheets oriented in the (0, 0, 1) direction. Ho is bonded in a square co-planar geometry to four equivalent S atoms. There are three shorter (2.66 Å) and one longer (2.67 Å) Ho–S bond lengths. S is bonded in a square co-planar geometry to four equivalent Ho atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Te3I(OF5)3 by Materials Project

Te3I(OF5)3 is alpha Niobium phosphide-derived structured and crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of two Te3I(OF5)3 clusters. there are three inequivalent Te+5.33+ sites. In the first Te+5.33+ site, Te+5.33+ is bonded in an octahedral geometry to one O2- and five F1- atoms. The Te–O bond length is 1.89 Å. There are a spread of Te–F bond distances ranging from 1.87–1.92 Å. In the second Te+5.33+ site, Te+5.33+ is bonded in an octahedral geometry to one O2- and five F1- atoms. The Te–O bond length is 1.91 Å. There are a spread of Te–F bond distances ranging from 1.87–1.89 Å. In the third Te+5.33+ site, Te+5.33+ is bonded in an octahedral geometry to one O2- and five F1- atoms. The Te–O bond length is 1.97 Å. There are a spread of Te–F bond distances ranging from 1.86–1.88 Å. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to one Te+5.33+ and one I5+ atom. The O–I bond length is 2.06 Å. In the second O2- site, O2- is bonded in a bent 120 degrees geometry to one Te+5.33+ and one I5+ atom. The O–I bond length is 1.95 Å. In the third O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Te+5.33+ and one I5+ atom. The O–I bond length is 2.10 Å. I5+ is bonded in a distorted rectangular see-saw-like geometry to three O2- and one F1- atom. The I–F bond length is 2.91 Å. There are fifteen inequivalent F1- sites. In the first F1- site, F1- is bonded in a single-bond geometry to one Te+5.33+ atom. In the second F1- site, F1- is bonded in a single-bond geometry to one Te+5.33+ atom. In the third F1- site, F1- is bonded in a single-bond geometry to one Te+5.33+ and one I5+ atom. In the fourth F1- site, F1- is bonded in a single-bond geometry to one Te+5.33+ atom. In the fifth F1- site, F1- is bonded in a single-bond geometry to one Te+5.33+ atom. In the sixth F1- site, F1- is bonded in a single-bond geometry to one Te+5.33+ atom. In the seventh F1- site, F1- is bonded in a single-bond geometry to one Te+5.33+ atom. In the eighth F1- site, F1- is bonded in a single-bond geometry to one Te+5.33+ atom. In the ninth F1- site, F1- is bonded in a single-bond geometry to one Te+5.33+ atom. In the tenth F1- site, F1- is bonded in a single-bond geometry to one Te+5.33+ atom. In the eleventh F1- site, F1- is bonded in a single-bond geometry to one Te+5.33+ atom. In the twelfth F1- site, F1- is bonded in a single-bond geometry to one Te+5.33+ atom. In the thirteenth F1- site, F1- is bonded in a single-bond geometry to one Te+5.33+ atom. In the fourteenth F1- site, F1- is bonded in a single-bond geometry to one Te+5.33+ atom. In the fifteenth F1- site, F1- is bonded in a single-bond geometry to one Te+5.33+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on PH3CS3 by Materials Project

CPH3S3 is alpha Niobium phosphide-derived structured and crystallizes in the monoclinic P2_1/c space group. The structure is zero-dimensional and consists of two CPH3S3 clusters. C2- is bonded in a trigonal non-coplanar geometry to three H1+ and one S2- atom. All C–H bond lengths are 1.10 Å. The C–S bond length is 1.81 Å. P5+ is bonded to four S2- atoms to form edge-sharing PS4 tetrahedra. There are a spread of P–S bond distances ranging from 1.93–2.15 Å. There are three inequivalent H1+ sites. In the first H1+ site, H1+ is bonded in a single-bond geometry to one C2- atom. In the second H1+ site, H1+ is bonded in a single-bond geometry to one C2- atom. In the third H1+ site, H1+ is bonded in a single-bond geometry to one C2- atom. There are three inequivalent S2- sites. In the first S2- site, S2- is bonded in a single-bond geometry to one P5+ atom. In the second S2- site, S2- is bonded in a water-like geometry to one C2- and one P5+ atom. In the third S2- site, S2- is bonded in an L-shaped geometry to two equivalent P5+ atoms.

36 MATERIALS SCIENCE↗