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Generalized nonlocal kinetic energy density functionals based on the von Weizsäcker functional
David García-Aldea1, José E Alvarellos
1Department of Physics and Astronomy, University of California Los Angeles, Los Angeles, CA 90095-1547, USA. dga@physics.ucla.edu
Physical Chemistry Chemical Physics : PCCP
|December 24, 2011
Summary
Researchers developed new nonlocal kinetic energy density functionals. These generalized von Weizsäcker functionals improve accuracy for localized systems and offer computational efficiency.
Area of Science:
- Computational physics
- Quantum chemistry
- Materials science
Background:
- Kinetic energy density functionals are crucial for electronic structure calculations.
- Existing methods like the von Weizsäcker functional have limitations in accuracy for localized systems.
- Nonlocal functionals aim to improve upon semilocal approximations.
Purpose of the Study:
- To generalize the von Weizsäcker functional by incorporating nonlocal terms.
- To develop new kinetic energy density functionals that accurately describe the linear response of the homogeneous electron gas.
- To assess the performance of these generalized functionals in localized systems.
Main Methods:
- Generalizing the von Weizsäcker functional using a parameter β to control electron density dependence.
- Constructing nonlocal terms that satisfy the linear response function of the homogeneous electron gas.
- Performing benchmark calculations on localized systems to evaluate relative errors and local behavior.
Main Results:
- The generalized nonlocal von Weizsäcker functionals yield competitive results compared to semilocal and previous nonlocal functionals.
- These new functionals provide very good estimates for total kinetic energies.
- Significant improvement in the description of the local behavior of the kinetic energy density was observed.
Conclusions:
- The developed generalized nonlocal von Weizsäcker functionals offer a promising approach for accurate electronic structure calculations.
- These functionals demonstrate improved accuracy and better local behavior compared to existing methods.
- The proposed functionals allow for efficient computation with quasilinear scaling, making them suitable for large systems.
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