The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform

Julien Toulouse - One of the best experts on this subject based on the ideXlab platform.

  • relativistic short range exchange Energy Functionals beyond the local density approximation
    Journal of Chemical Physics, 2020
    Co-Authors: Julien Paquier, Emmanuel Giner, Julien Toulouse
    Abstract:

    We develop relativistic short-range exchange Energy Functionals for four-component relativistic range-separated density-functional theory using a Dirac-Coulomb Hamiltonian in the no-pair approximation. We show how to improve the short-range local-density approximation exchange functional for large range-separation parameters by using the on-top exchange pair density as a new variable. We also develop a relativistic short-range generalized-gradient approximation exchange functional that further increases the accuracy for small range-separation parameters. Tests on the helium, beryllium, neon, and argon isoelectronic series up to high nuclear charges show that the latter functional gives exchange energies with a maximal relative percentage error of 3%. The development of this exchange functional represents a step forward for the application of four-component relativistic range-separated density-functional theory to chemical compounds with heavy elements.

  • Relativistic short-range exchange Energy Functionals beyond the local-density approximation
    Journal of Chemical Physics, 2020
    Co-Authors: Julien Paquier, Emmanuel Giner, Julien Toulouse
    Abstract:

    We develop relativistic short-range exchange Energy Functionals for four-component relativistic range-separated density-functional theory using a Dirac-Coulomb Hamiltonian in the no-pair approximation. We show how to improve the short-range local-density approximation exchange functional for large range-separation parameters by using the on-top exchange pair density as a new variable. We also develop a relativistic short-range generalized-gradient approximation exchange functional which further increases the accuracy for small range-separation parameters. Tests on the helium, beryllium, neon, and argon isoelectronic series up to high nuclear charges show that this latter functional gives exchange energies with a maximal relative percentage error of 3 %. The development of this exchange functional represents a step forward for the application of four-component relativistic range-separated density-functional theory to chemical compounds with heavy elements.

Julien Paquier - One of the best experts on this subject based on the ideXlab platform.

  • relativistic short range exchange Energy Functionals beyond the local density approximation
    Journal of Chemical Physics, 2020
    Co-Authors: Julien Paquier, Emmanuel Giner, Julien Toulouse
    Abstract:

    We develop relativistic short-range exchange Energy Functionals for four-component relativistic range-separated density-functional theory using a Dirac-Coulomb Hamiltonian in the no-pair approximation. We show how to improve the short-range local-density approximation exchange functional for large range-separation parameters by using the on-top exchange pair density as a new variable. We also develop a relativistic short-range generalized-gradient approximation exchange functional that further increases the accuracy for small range-separation parameters. Tests on the helium, beryllium, neon, and argon isoelectronic series up to high nuclear charges show that the latter functional gives exchange energies with a maximal relative percentage error of 3%. The development of this exchange functional represents a step forward for the application of four-component relativistic range-separated density-functional theory to chemical compounds with heavy elements.

  • Relativistic short-range exchange Energy Functionals beyond the local-density approximation
    Journal of Chemical Physics, 2020
    Co-Authors: Julien Paquier, Emmanuel Giner, Julien Toulouse
    Abstract:

    We develop relativistic short-range exchange Energy Functionals for four-component relativistic range-separated density-functional theory using a Dirac-Coulomb Hamiltonian in the no-pair approximation. We show how to improve the short-range local-density approximation exchange functional for large range-separation parameters by using the on-top exchange pair density as a new variable. We also develop a relativistic short-range generalized-gradient approximation exchange functional which further increases the accuracy for small range-separation parameters. Tests on the helium, beryllium, neon, and argon isoelectronic series up to high nuclear charges show that this latter functional gives exchange energies with a maximal relative percentage error of 3 %. The development of this exchange functional represents a step forward for the application of four-component relativistic range-separated density-functional theory to chemical compounds with heavy elements.

Emmanuel Giner - One of the best experts on this subject based on the ideXlab platform.

  • relativistic short range exchange Energy Functionals beyond the local density approximation
    Journal of Chemical Physics, 2020
    Co-Authors: Julien Paquier, Emmanuel Giner, Julien Toulouse
    Abstract:

    We develop relativistic short-range exchange Energy Functionals for four-component relativistic range-separated density-functional theory using a Dirac-Coulomb Hamiltonian in the no-pair approximation. We show how to improve the short-range local-density approximation exchange functional for large range-separation parameters by using the on-top exchange pair density as a new variable. We also develop a relativistic short-range generalized-gradient approximation exchange functional that further increases the accuracy for small range-separation parameters. Tests on the helium, beryllium, neon, and argon isoelectronic series up to high nuclear charges show that the latter functional gives exchange energies with a maximal relative percentage error of 3%. The development of this exchange functional represents a step forward for the application of four-component relativistic range-separated density-functional theory to chemical compounds with heavy elements.

  • Relativistic short-range exchange Energy Functionals beyond the local-density approximation
    Journal of Chemical Physics, 2020
    Co-Authors: Julien Paquier, Emmanuel Giner, Julien Toulouse
    Abstract:

    We develop relativistic short-range exchange Energy Functionals for four-component relativistic range-separated density-functional theory using a Dirac-Coulomb Hamiltonian in the no-pair approximation. We show how to improve the short-range local-density approximation exchange functional for large range-separation parameters by using the on-top exchange pair density as a new variable. We also develop a relativistic short-range generalized-gradient approximation exchange functional which further increases the accuracy for small range-separation parameters. Tests on the helium, beryllium, neon, and argon isoelectronic series up to high nuclear charges show that this latter functional gives exchange energies with a maximal relative percentage error of 3 %. The development of this exchange functional represents a step forward for the application of four-component relativistic range-separated density-functional theory to chemical compounds with heavy elements.

Prasanjit Samal - One of the best experts on this subject based on the ideXlab platform.

  • adiabatic connection in density functional theory in two dimensions a semi analytic wavefunction based study for two electron atomic systems
    Journal of Chemical Physics, 2019
    Co-Authors: Rabeet Singh, Abhilash Patra, Bikash Patra, Manoj K Harbola, Prasanjit Samal
    Abstract:

    This work focuses on studying the adiabatic-connection in density functional theory in two dimensions. It employs a recently developed accurate form of wavefunction for two-electron systems. The explicit semianalytic form of the wavefunction makes it possible to calculate ground state wavefunctions, energies, densities, and the resulting properties for the scaled Coulomb interaction between the electrons at fixed density accurately. The results so obtained for the correlation energies are then used as the reference values for studying the performance of two-dimensional correlation Energy Functionals.

  • inhomogeneity induced and appropriately parameterized semilocal exchange and correlation Energy Functionals in two dimensions
    Journal of Chemical Physics, 2018
    Co-Authors: Abhilash Patra, Subrata Jana, Prasanjit Samal
    Abstract:

    The construction of meta generalized gradient approximations based on the density matrix expansion (DME) is considered as one of the most accurate techniques to design semilocal exchange Energy Functionals in two-dimensional density functional formalism. The exchange holes modeled using DME possess unique features that make it a superior entity. Parameterized semilocal exchange Energy Functionals based on the DME are proposed. The use of different forms of the momentum and flexible parameters is to subsume the non-uniform effects of the density in the newly constructed semilocal Functionals. In addition to the exchange Functionals, a suitable correlation functional is also constructed by working upon the local correlation functional developed for 2D homogeneous electron gas. The non-local effects are induced into the correlation functional by a parametric form of one of the newly constructed exchange Energy Functionals. The proposed Functionals are applied to the parabolic quantum dots with a varying numb...

  • inhomogeneity induced and appropriately parameterized semilocal exchange and correlation Energy Functionals in two dimensions
    arXiv: Materials Science, 2017
    Co-Authors: Abhilash Patra, Subrata Jana, Prasanjit Samal
    Abstract:

    The construction of meta generalized gradient approximations based on the density matrix expansion (DME) is considered as one of the most accurate technique to design semilocal exchange Energy Functionals in two-dimensional density functional formalism. The exchange holes modeled using DME possess unique features that make it a superior entity. Parameterized semilocal exchange Energy Functionals based on the DME are proposed. The use of different forms of the momentum and flexible parameters is to subsume the non-uniform effects of the density in the newly constructed semilocal Functionals. In addition to the exchange Functionals, a suitable correlation functional is also constructed by working upon the local correlation functional developed for 2D homogeneous electron gas (2D-HEG). The non-local effects are induced into the correlation functional by a parametric form of one of the newly constructed exchange Energy Functionals. The proposed Functionals are applied to the parabolic quantum dots with a varying number of confined electrons and the confinement strength. The results obtained with the aforementioned Functionals are quite satisfactory which indicates why these are suitable for two-dimensional quantum systems.

Abhilash Patra - One of the best experts on this subject based on the ideXlab platform.

  • adiabatic connection in density functional theory in two dimensions a semi analytic wavefunction based study for two electron atomic systems
    Journal of Chemical Physics, 2019
    Co-Authors: Rabeet Singh, Abhilash Patra, Bikash Patra, Manoj K Harbola, Prasanjit Samal
    Abstract:

    This work focuses on studying the adiabatic-connection in density functional theory in two dimensions. It employs a recently developed accurate form of wavefunction for two-electron systems. The explicit semianalytic form of the wavefunction makes it possible to calculate ground state wavefunctions, energies, densities, and the resulting properties for the scaled Coulomb interaction between the electrons at fixed density accurately. The results so obtained for the correlation energies are then used as the reference values for studying the performance of two-dimensional correlation Energy Functionals.

  • inhomogeneity induced and appropriately parameterized semilocal exchange and correlation Energy Functionals in two dimensions
    Journal of Chemical Physics, 2018
    Co-Authors: Abhilash Patra, Subrata Jana, Prasanjit Samal
    Abstract:

    The construction of meta generalized gradient approximations based on the density matrix expansion (DME) is considered as one of the most accurate techniques to design semilocal exchange Energy Functionals in two-dimensional density functional formalism. The exchange holes modeled using DME possess unique features that make it a superior entity. Parameterized semilocal exchange Energy Functionals based on the DME are proposed. The use of different forms of the momentum and flexible parameters is to subsume the non-uniform effects of the density in the newly constructed semilocal Functionals. In addition to the exchange Functionals, a suitable correlation functional is also constructed by working upon the local correlation functional developed for 2D homogeneous electron gas. The non-local effects are induced into the correlation functional by a parametric form of one of the newly constructed exchange Energy Functionals. The proposed Functionals are applied to the parabolic quantum dots with a varying numb...

  • inhomogeneity induced and appropriately parameterized semilocal exchange and correlation Energy Functionals in two dimensions
    arXiv: Materials Science, 2017
    Co-Authors: Abhilash Patra, Subrata Jana, Prasanjit Samal
    Abstract:

    The construction of meta generalized gradient approximations based on the density matrix expansion (DME) is considered as one of the most accurate technique to design semilocal exchange Energy Functionals in two-dimensional density functional formalism. The exchange holes modeled using DME possess unique features that make it a superior entity. Parameterized semilocal exchange Energy Functionals based on the DME are proposed. The use of different forms of the momentum and flexible parameters is to subsume the non-uniform effects of the density in the newly constructed semilocal Functionals. In addition to the exchange Functionals, a suitable correlation functional is also constructed by working upon the local correlation functional developed for 2D homogeneous electron gas (2D-HEG). The non-local effects are induced into the correlation functional by a parametric form of one of the newly constructed exchange Energy Functionals. The proposed Functionals are applied to the parabolic quantum dots with a varying number of confined electrons and the confinement strength. The results obtained with the aforementioned Functionals are quite satisfactory which indicates why these are suitable for two-dimensional quantum systems.