The Experts below are selected from a list of 285 Experts worldwide ranked by ideXlab platform
Matthias Ernzerhof - One of the best experts on this subject based on the ideXlab platform.
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Erratum: “Hybrid functionals based on a screened Coulomb Potential” [J. Chem. Phys. 118, 8207 (2003)]
The Journal of Chemical Physics, 2006Co-Authors: Jochen Heyd, Gustavo E Scuseria, Matthias ErnzerhofAbstract:Hybrid density functionals are very successful in describing a wide range of molecular properties accurately. In large molecules and solids, however, calculating the exact (Hartree-Fock) exchange is computationally expensive, especially for systems with metallic characteristics. In the present work, we develop a new hybrid density functional based on a screened Coulomb Potential for the exchange interaction which circumvents this bottleneck. The results obtained for structural and thermodynamic properties of molecules are comparable in quality to the most widely used hybrid functionals. In addition, we present results of periodic boundary condition calculations for both semiconducting and metallic single wall carbon nanotubes. Using a screened Coulomb Potential for Hartree-Fock exchange enables fast and accurate hybrid calculations, even of usually difficult metallic systems. The high accuracy of the new screened Coulomb Potential hybrid, combined with its computational advantages, makes it widely applicable to large molecules and periodic systems. (C) 2003 American Institute of Physics.
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hybrid functionals based on a screened Coulomb Potential
Journal of Chemical Physics, 2003Co-Authors: Jochen Heyd, Gustavo E Scuseria, Matthias ErnzerhofAbstract:Hybrid density functionals are very successful in describing a wide range of molecular properties accurately. In large molecules and solids, however, calculating the exact (Hartree–Fock) exchange is computationally expensive, especially for systems with metallic characteristics. In the present work, we develop a new hybrid density functional based on a screened Coulomb Potential for the exchange interaction which circumvents this bottleneck. The results obtained for structural and thermodynamic properties of molecules are comparable in quality to the most widely used hybrid functionals. In addition, we present results of periodic boundary condition calculations for both semiconducting and metallic single wall carbon nanotubes. Using a screened Coulomb Potential for Hartree–Fock exchange enables fast and accurate hybrid calculations, even of usually difficult metallic systems. The high accuracy of the new screened Coulomb Potential hybrid, combined with its computational advantages, makes it widely applicable to large molecules and periodic systems.
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Hybrid functionals based on a screened Coulomb Potential
The Journal of Chemical Physics, 2003Co-Authors: Jochen Heyd, Gustavo E Scuseria, Matthias ErnzerhofAbstract:Hybrid density functionals are very successful in describing a wide range of molecular properties accurately. In large molecules and solids, however, calculating the exact (Hartree–Fock) exchange is computationally expensive, especially for systems with metallic characteristics. In the present work, we develop a new hybrid density functional based on a screened Coulomb Potential for the exchange interaction which circumvents this bottleneck. The results obtained for structural and thermodynamic properties of molecules are comparable in quality to the most widely used hybrid functionals. In addition, we present results of periodic boundary condition calculations for both semiconducting and metallic single wall carbon nanotubes. Using a screened Coulomb Potential for Hartree–Fock exchange enables fast and accurate hybrid calculations, even of usually difficult metallic systems. The high accuracy of the new screened Coulomb Potential hybrid, combined with its computational advantages, makes it widely applica...
Jochen Heyd - One of the best experts on this subject based on the ideXlab platform.
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Erratum: “Hybrid functionals based on a screened Coulomb Potential” [J. Chem. Phys. 118, 8207 (2003)]
The Journal of Chemical Physics, 2006Co-Authors: Jochen Heyd, Gustavo E Scuseria, Matthias ErnzerhofAbstract:Hybrid density functionals are very successful in describing a wide range of molecular properties accurately. In large molecules and solids, however, calculating the exact (Hartree-Fock) exchange is computationally expensive, especially for systems with metallic characteristics. In the present work, we develop a new hybrid density functional based on a screened Coulomb Potential for the exchange interaction which circumvents this bottleneck. The results obtained for structural and thermodynamic properties of molecules are comparable in quality to the most widely used hybrid functionals. In addition, we present results of periodic boundary condition calculations for both semiconducting and metallic single wall carbon nanotubes. Using a screened Coulomb Potential for Hartree-Fock exchange enables fast and accurate hybrid calculations, even of usually difficult metallic systems. The high accuracy of the new screened Coulomb Potential hybrid, combined with its computational advantages, makes it widely applicable to large molecules and periodic systems. (C) 2003 American Institute of Physics.
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hybrid functionals based on a screened Coulomb Potential
Journal of Chemical Physics, 2003Co-Authors: Jochen Heyd, Gustavo E Scuseria, Matthias ErnzerhofAbstract:Hybrid density functionals are very successful in describing a wide range of molecular properties accurately. In large molecules and solids, however, calculating the exact (Hartree–Fock) exchange is computationally expensive, especially for systems with metallic characteristics. In the present work, we develop a new hybrid density functional based on a screened Coulomb Potential for the exchange interaction which circumvents this bottleneck. The results obtained for structural and thermodynamic properties of molecules are comparable in quality to the most widely used hybrid functionals. In addition, we present results of periodic boundary condition calculations for both semiconducting and metallic single wall carbon nanotubes. Using a screened Coulomb Potential for Hartree–Fock exchange enables fast and accurate hybrid calculations, even of usually difficult metallic systems. The high accuracy of the new screened Coulomb Potential hybrid, combined with its computational advantages, makes it widely applicable to large molecules and periodic systems.
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Hybrid functionals based on a screened Coulomb Potential
The Journal of Chemical Physics, 2003Co-Authors: Jochen Heyd, Gustavo E Scuseria, Matthias ErnzerhofAbstract:Hybrid density functionals are very successful in describing a wide range of molecular properties accurately. In large molecules and solids, however, calculating the exact (Hartree–Fock) exchange is computationally expensive, especially for systems with metallic characteristics. In the present work, we develop a new hybrid density functional based on a screened Coulomb Potential for the exchange interaction which circumvents this bottleneck. The results obtained for structural and thermodynamic properties of molecules are comparable in quality to the most widely used hybrid functionals. In addition, we present results of periodic boundary condition calculations for both semiconducting and metallic single wall carbon nanotubes. Using a screened Coulomb Potential for Hartree–Fock exchange enables fast and accurate hybrid calculations, even of usually difficult metallic systems. The high accuracy of the new screened Coulomb Potential hybrid, combined with its computational advantages, makes it widely applica...
I V Mamsurov - One of the best experts on this subject based on the ideXlab platform.
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planar density of vacuum charge induced by a supercritical Coulomb Potential
Physics Letters B, 2017Co-Authors: V R Khalilov, I V MamsurovAbstract:Abstract Analytical expressions for the planar density of an induced vacuum charge are obtained in a strong Coulomb Potential in coordinate space. Treatment is based on a self-adjoint extension approach for constructing of the Green's function of a charged fermion in an external electromagnetic field. Induced vacuum charge density is calculated and analyzed in subcritical and supercritical Coulomb Potentials for massless and massive fermions. We argue that the virtual and so-called real vacuum polarizations contribute in an induced vacuum charge in a supercritical Coulomb Potential. The behavior of the polarization vacuum charge density is investigated at long and short distances from the Coulomb center. The induced vacuum charge has a screening sign. Screening of a Coulomb impurity in graphene is briefly discussed. The real vacuum polarization charge density that acquires the quantum electrodynamics vacuum in a supercritical Coulomb Potential due to the real vacuum polarization is calculated. It is shown that the vacuum charge densities essentially differ in massive and massless cases. We expect that our results can, as a matter of principle, be tested in graphene with a supercritical Coulomb impurity.
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Vacuum polarization of planar Dirac fermions by a superstrong Coulomb Potential
arXiv: Quantum Physics, 2016Co-Authors: V R Khalilov, I V MamsurovAbstract:We study the vacuum polarization of planar charged Dirac fermions by a strong Coulomb Potential. Induced vacuum charge density is calculated and analyzed at the subcritical and supercritical Coulomb Potentials for massless and massive fermions. For the massless case the induced vacuum charge density is localized at the origin when the Coulomb center charge is subcritical while it has a power-law tail when the Coulomb center charge is supercritical. The finite mass contribution into the induced charge due to the vacuum polarization is small and insignificantly distorts the Coulomb Potential only at distances of order of the Compton length. The induced vacuum charge has a screening sign. As is known the quantum electrodynamics vacuum becomes unstable when the Coulomb center charge is increased from subcritical to supercritical values. In the supercritical Coulomb Potential the quantum electrodynamics vacuum acquires the charge due to the so-called real vacuum polarization. We calculate the real vacuum polarization charge density. Screening of the Coulomb center charge are briefly discussed. We expect that our results will be helpful for more deep understanding of the fundamental problem of quantum electrodynamics and can as a matter of principle be tested in graphene with a supercritical Coulomb impurity.
Gustavo E Scuseria - One of the best experts on this subject based on the ideXlab platform.
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Erratum: “Hybrid functionals based on a screened Coulomb Potential” [J. Chem. Phys. 118, 8207 (2003)]
The Journal of Chemical Physics, 2006Co-Authors: Jochen Heyd, Gustavo E Scuseria, Matthias ErnzerhofAbstract:Hybrid density functionals are very successful in describing a wide range of molecular properties accurately. In large molecules and solids, however, calculating the exact (Hartree-Fock) exchange is computationally expensive, especially for systems with metallic characteristics. In the present work, we develop a new hybrid density functional based on a screened Coulomb Potential for the exchange interaction which circumvents this bottleneck. The results obtained for structural and thermodynamic properties of molecules are comparable in quality to the most widely used hybrid functionals. In addition, we present results of periodic boundary condition calculations for both semiconducting and metallic single wall carbon nanotubes. Using a screened Coulomb Potential for Hartree-Fock exchange enables fast and accurate hybrid calculations, even of usually difficult metallic systems. The high accuracy of the new screened Coulomb Potential hybrid, combined with its computational advantages, makes it widely applicable to large molecules and periodic systems. (C) 2003 American Institute of Physics.
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hybrid functionals based on a screened Coulomb Potential
Journal of Chemical Physics, 2003Co-Authors: Jochen Heyd, Gustavo E Scuseria, Matthias ErnzerhofAbstract:Hybrid density functionals are very successful in describing a wide range of molecular properties accurately. In large molecules and solids, however, calculating the exact (Hartree–Fock) exchange is computationally expensive, especially for systems with metallic characteristics. In the present work, we develop a new hybrid density functional based on a screened Coulomb Potential for the exchange interaction which circumvents this bottleneck. The results obtained for structural and thermodynamic properties of molecules are comparable in quality to the most widely used hybrid functionals. In addition, we present results of periodic boundary condition calculations for both semiconducting and metallic single wall carbon nanotubes. Using a screened Coulomb Potential for Hartree–Fock exchange enables fast and accurate hybrid calculations, even of usually difficult metallic systems. The high accuracy of the new screened Coulomb Potential hybrid, combined with its computational advantages, makes it widely applicable to large molecules and periodic systems.
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Hybrid functionals based on a screened Coulomb Potential
The Journal of Chemical Physics, 2003Co-Authors: Jochen Heyd, Gustavo E Scuseria, Matthias ErnzerhofAbstract:Hybrid density functionals are very successful in describing a wide range of molecular properties accurately. In large molecules and solids, however, calculating the exact (Hartree–Fock) exchange is computationally expensive, especially for systems with metallic characteristics. In the present work, we develop a new hybrid density functional based on a screened Coulomb Potential for the exchange interaction which circumvents this bottleneck. The results obtained for structural and thermodynamic properties of molecules are comparable in quality to the most widely used hybrid functionals. In addition, we present results of periodic boundary condition calculations for both semiconducting and metallic single wall carbon nanotubes. Using a screened Coulomb Potential for Hartree–Fock exchange enables fast and accurate hybrid calculations, even of usually difficult metallic systems. The high accuracy of the new screened Coulomb Potential hybrid, combined with its computational advantages, makes it widely applica...
Armen Nersessian - One of the best experts on this subject based on the ideXlab platform.
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spherical calogero model with oscillator Coulomb Potential quantum case
Physical Review D, 2016Co-Authors: Francisco Correa, Tigran Hakobyan, Olaf Lechtenfeld, Armen NersessianAbstract:We consider the quantum mechanics of Calogero models in an oscillator or Coulomb Potential on the N-dimensional sphere. Their Hamiltonians are obtained by an appropriate Dunkl deformation of the oscillator/Coulomb system on the sphere and its restriction to (Coxeter reflection) symmetric wave functions. By the same method we also find the symmetry generators and compute their algebras.
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superintegrability of generalized calogero models with oscillator or Coulomb Potential
Physical Review D, 2014Co-Authors: Tigran Hakobyan, Olaf Lechtenfeld, Armen NersessianAbstract:We deform N-dimensional (Euclidean, spherical and hyperbolic) oscillator and Coulomb systems, replacing their angular degrees of freedom by those of a generalized rational Calogero model. Using the action-angle description, it is established that maximal superintegrability is retained. For the rational Calogero model with Coulomb Potential, we present all constants of motion via matrix model reduction. In particular, we construct the analog of the Runge-Lenz vector.
