scholarly journals Condensation energy of the homogeneous electron gas from density-functional theory for superconductors

2005 ◽  
Vol 71 (1) ◽  
Author(s):  
M. Wierzbowska ◽  
J. W. Krogh
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Electron Gas ◽  
Condensation Energy ◽  
Functional Theory

scholarly journals TIME-DEPENDENT CURRENT-DENSITY FUNCTIONAL THEORY FOR THE FRICTION OF IONS IN AN INTERACTING ELECTRON GAS

2008 ◽  
Vol 22 (22) ◽  
pp. 3813-3839 ◽  
Author(s):  
V. U. NAZAROV ◽  
J. M. PITARKE ◽  
Y. TAKADA ◽  
G. VIGNALE ◽  
Y.-C. CHANG
Keyword(s):  
Density Functional Theory ◽  
Current Density ◽  
Density Functional ◽  
Local Density ◽  
Electron Gas ◽  
Time Dependent ◽  
Functional Theory ◽  
A Value ◽  
Slow Ions ◽  
Nonlocal Nature

Due to the strongly nonlocal nature of fxc(r,r',ω), the scalar exchange and correlation (xc) kernel of the time-dependent density functional theory (TDDFT), the formula for Q the friction coefficient of an interacting electron gas (EG) for ions tends to give too large a value of Q for heavy ions in the medium- and low-density EG, if we adopt the local-density approximation (LDA) to fxc(r, r', ω), even though the formula itself is formally exact. We have rectified this unfavorable feature by reformulating the formula for Q in terms of the tensorialxc kernel of the time-dependent current-density functional theory, to which the LDA can be applied without intrinsic difficulty. Our numerical results find themselves in considerably better agreement with the experimental stopping power of Al and Au for slow ions than those previously obtained within the LDA to the TDDFT.

scholarly journals Properties of the Free-Standing Two-Dimensional Copper Monolayer

2016 ◽  
Vol 2016 ◽  
pp. 1-6 ◽  
Author(s):  
Li-Ming Yang ◽  
Thomas Frauenheim ◽  
Eric Ganz
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Valence Electron ◽  
Global Minimum ◽  
Electron Gas ◽  
Two Dimensional ◽  
Free Standing ◽  
Functional Theory ◽  
Hexagonal Close Packed ◽  
Dynamics Simulations

We use density functional theory to study a free-standing 2D copper monolayer. We find that the Cu monolayer is stable in 15 ps ab initio molecular dynamics simulations up to 1200 K. Due to the smaller number of bonds per atom in the 2D layer compared to the 3D bulk, we observe a significantly enhanced energy per bond (0.92 versus 0.58 eV/bond). This is similar to the increase in bond strength going from 3D diamond to 2D graphene. We predict various properties of this material, including band structure and density of states. The free-standing 2D Cu monolayer is hexagonal close packed and is the global minimum structure. One valence electron from each atom is delocalized and is donated into a 2D nearly free electron gas.

scholarly journals Approximate bounds and temperature dependence of adiabatic connection integrands for the uniform electron gas

2021 ◽  
Author(s):  
Brittany P. Harding ◽  
Zachary Mauri ◽  
Aurora Pribram-Jones
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Correlation Energy ◽  
Electron Gas ◽  
High Energy ◽  
Zero Temperature ◽  
Temperature Dependent ◽  
Functional Theory ◽  
Exchange Correlation ◽  
Uniform Electron Gas

Thermal density functional theory is commonly used in simulations of warm dense matter, a highly energetic phase characterized by substantial thermal effects and by correlated electrons demanding quantum mechanical treatment. The numerous approximations for the exchange-correlation energy component in zero-temperature density functional theory, though often used in these high-energy-density simulations with Fermi-weighted electronic densities, are known to miss temperature-dependent effects in the electronic structure of these systems. In this work, the temperature-dependent adiabatic connection is demonstrated and analyzed using a well-known parameterization of the uniform electron gas free energy. Useful tools based on this formalism for analyzing and constraining approximations of the exchange-correlation at zero temperature are leveraged for the finite-temperature case. Inspired by the Lieb-Oxford inequality, which provides a lower bound for the ground-state exchange-correlation energy, bounds for the exchange-correlation at finite temperatures are approximated for various degrees of electronic correlation.

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