Reinvestigation of the ideal atomic shell structure and its application in orbital-free density functional theory

2016 ◽  
Vol 135 (4) ◽  
Author(s):  
K. Finzel
Keyword(s):  
Density Functional Theory ◽  
Shell Structure ◽  
Density Functional ◽  
Atomic Shell ◽  
Functional Theory ◽  
Atomic Shell Structure ◽  
Orbital Free ◽  
The Ideal

scholarly journals ATLAS: A real-space finite-difference implementation of orbital-free density functional theory

2016 ◽  
Vol 200 ◽  
pp. 87-95 ◽  
Author(s):  
Wenhui Mi ◽  
Xuecheng Shao ◽  
Chuanxun Su ◽  
Yuanyuan Zhou ◽  
Shoutao Zhang ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Finite Difference ◽  
Density Functional ◽  
Real Space ◽  
Functional Theory ◽  
Orbital Free

Theoretical determination of the structures of CaSiO3 perovskites

2006 ◽  
Vol 62 (6) ◽  
pp. 1025-1030 ◽  
Author(s):  
Razvan Caracas ◽  
Renata M. Wentzcovitch
Keyword(s):  
Crystal Structure ◽  
Experimental Data ◽  
Density Functional Theory ◽  
Density Functional ◽  
Theoretical Determination ◽  
Functional Theory ◽  
Starting Point ◽  
Atomic Coordinates ◽  
The Ideal

Density functional theory is used to determine the possible crystal structure of the CaSiO3 perovskites and their evolution under pressure. The ideal cubic perovskite is considered as a starting point for studying several possible lower-symmetry distorted structures. The theoretical lattice parameters and the atomic coordinates for all the structures are determined, and the results are discussed with respect to experimental data.

Developing orbital-free quantum crystallography: the local potentials and associated partial charge densities

2021 ◽  
Vol 77 (4) ◽  
Author(s):  
Vladimir Tsirelson ◽  
Adam Stash
Keyword(s):  
Density Functional Theory ◽  
Electron Density ◽  
Density Functional ◽  
Electronic Energy ◽  
Physical Content ◽  
Functional Theory ◽  
Orbital Free ◽  
The One ◽  
Physical And Chemical ◽  
Quantum Crystallography

This work extends the orbital-free density functional theory to the field of quantum crystallography. The total electronic energy is decomposed into electrostatic, exchange, Weizsacker and Pauli components on the basis of physically grounded arguments. Then, the one-electron Euler equation is re-written through corresponding potentials, which have clear physical and chemical meaning. Partial electron densities related with these potentials by the Poisson equation are also defined. All these functions were analyzed from viewpoint of their physical content and limits of applicability. Then, they were expressed in terms of experimental electron density and its derivatives using the orbital-free density functional theory approximations, and applied to the study of chemical bonding in a heteromolecular crystal of ammonium hydrooxalate oxalic acid dihydrate. It is demonstrated that this approach allows the electron density to be decomposed into physically meaningful components associated with electrostatics, exchange, and spin-independent wave properties of electrons or with their combinations in a crystal. Therefore, the bonding information about a crystal that was previously unavailable for X-ray diffraction analysis can be now obtained.

scholarly journals Discontinuous Behavior of the Pauli Potential in Density Functional Theory as a Function of the Electron Number

2019 ◽  
Author(s):  
Eli Kraisler ◽  
Axel Schild
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Electron Systems ◽  
Electron Number ◽  
Functional Theory ◽  
Fractional Number ◽  
Finite Systems ◽  
Pauli Potential ◽  
Spin Polarized ◽  
Orbital Free

<div>The Pauli potential is an essential quantity in orbital-free density-functional theory (DFT) and in the exact electron factorization (EEF) method for many-electron systems. Knowledge of the Pauli potential allows the description of a system relying on the density alone, without the need to calculate the orbitals.</div><div>In this work we explore the behavior of the exact Pauli potential in finite systems as a function of the number of electrons, employing the ensemble approach in DFT. Assuming the system is in contact with an electron reservoir, we allow the number of electrons to vary continuously and to obtain fractional as well as integer values. We derive an expression for the Pauli potential for a spin-polarized system with a fractional number of electrons and find that when the electron number surpasses an integer, the Pauli potential jumps by a spatially uniform constant, similarly to the Kohn-Sham potential. The magnitude of the jump equals the Kohn-Sham gap. We illustrate our analytical findings by calculating the exact and approximate Pauli potentials for Li and Na atoms with fractional numbers of electrons.</div>

scholarly journals Orbital-free density functional theory implementation with the projector augmented-wave method

2014 ◽  
Vol 141 (23) ◽  
pp. 234102 ◽  
Author(s):  
Jouko Lehtomäki ◽  
Ilja Makkonen ◽  
Miguel A. Caro ◽  
Ari Harju ◽  
Olga Lopez-Acevedo
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Wave Method ◽  
Functional Theory ◽  
Orbital Free ◽  
Projector Augmented Wave
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