Conceptual Problem with Calculating Electron Densities in Finite Basis Density Functional Theory

2017 ◽  
Vol 13 (9) ◽  
pp. 3961-3963 ◽  
Author(s):  
István Mayer ◽  
Imre Pápai ◽  
Imre Bakó ◽  
Ágnes Nagy
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Finite Basis ◽  
Conceptual Problem ◽  
Electron Densities ◽  
Functional Theory

scholarly journals Accurate Calculation of CBED Patterns for 4D STEM Using Electron Densities Calculated by Density Functional Theory.

2018 ◽  
Vol 24 (S1) ◽  
pp. 116-117
Author(s):  
Mark P. Oxley ◽  
Axiel Yael Birenbaum ◽  
Tribhuwan Pandey ◽  
Valentino R. Cooper ◽  
Miaofang Chi
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Accurate Calculation ◽  
Electron Densities ◽  
Functional Theory

ALGEBRAIC EQUATION AND ITERATIVE OPTIMIZATION FOR THE OPTIMIZED EFFECTIVE POTENTIAL IN DENSITY FUNCTIONAL THEORY

2003 ◽  
Vol 02 (04) ◽  
pp. 627-638 ◽  
Author(s):  
QIN WU ◽  
WEITAO YANG
Keyword(s):  
Density Functional Theory ◽  
Algebraic Equation ◽  
Effective Potential ◽  
Density Functional ◽  
Finite Basis ◽  
Basis Set ◽  
Optimization Approach ◽  
Second Derivative ◽  
Functional Theory ◽  
Derivative Matrix

We further develop our recent direct method for the optimized effective potential (OEP) in density functional theory (DFT) [Yang and Wu, Phys. Rev. Lett.89, 143002 (2002)]. First, we show that the stationary condition in our optimization approach leads to a proper nonlinear algebraic equation for the OEP in a finite basis set, which differs from other finite basis set approaches. Then by constructing an approximate second derivative matrix of the energy functional in conjunction with the use of the Newton method, we significantly accelerate the convergence of the iterative optimization for OEP. Enhancement of the method is made in using the Tikhonov regularization method for the inversion of the second derivative matrix when it is singular or nearly singular and the direct inversion in the iterative space. It is shown that under a fixed stepsize condition, the optimization approach is equivalent to the self-consistent solution to the nonlinear algebraic equation for OEP. Because the approximate second derivatives are easy to compute and the iteration numbers are small now, the computation costs of OEP become comparable to that of regular DFT calculations as shown by calculations of some molecules, small and larger ones. We show how to find balanced results between energies and potentials when choosing a basis set for potentials.

Topological analysis of electron densities from Kohn-Sham and subsystem density functional theory

2008 ◽  
Vol 128 (4) ◽  
pp. 044114 ◽  
Author(s):  
Karin Kiewisch ◽  
Georg Eickerling ◽  
Markus Reiher ◽  
Johannes Neugebauer
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Topological Analysis ◽  
Electron Densities ◽  
Functional Theory

scholarly journals Kohn—Sham density-functional theory within a finite basis set

1992 ◽  
Vol 199 (6) ◽  
pp. 557-560 ◽  
Author(s):  
John A. Pople ◽  
Peter M.W. Gill ◽  
Benny G. Johnson
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Finite Basis ◽  
Basis Set ◽  
Functional Theory

scholarly journals Localizing electron density errors in density functional theory

2019 ◽  
Vol 21 (37) ◽  
pp. 20927-20938 ◽  
Author(s):  
Rubén Laplaza ◽  
Victor Polo ◽  
Julia Contreras-García
Keyword(s):  
Density Functional Theory ◽  
Electron Density ◽  
Quantum Chemical ◽  
Density Functional ◽  
Electron Densities ◽  
Functional Theory ◽  
Chemical Topology ◽  
Molecular Electron ◽  
Quantum Chemical Topology

The accuracy of different density functional approximations is assessed through the use of quantum chemical topology on molecular electron densities.

Simulation Investigation of Bis(pentaphospholyl) Metallocenes of Fe, Ru, and Os

2013 ◽  
Vol 763 ◽  
pp. 139-142
Author(s):  
Liang Fa Gong ◽  
Qi Qun Cao ◽  
Jia Wen ◽  
Hua Rong ◽  
Ming Lan Ge
Keyword(s):  
Density Functional Theory ◽  
Transition State ◽  
Density Functional ◽  
Global Minimum ◽  
Rotational Transition ◽  
Metal Ring ◽  
Electron Densities ◽  
Functional Theory ◽  
Metal Centers ◽  
Π Interactions

The structures, stabilities, and bonding features of neutral M(η5-P5)2 (M = Fe, Ru, and Os) and cationic M(η5-P5)+ have been investigated using density functional theory (DFT) (hybrid B3LYP and pure BP86 methods). The eclipsed (D5h) structure has been predicted to be the global minimum for this triad bis(pentaphospholyl) metallocenes, and the staggered (D5d) structure to be the rotational transition state. The distances between the metal and cyclo-P5 center in bis(pentaphospholyl) metallocenes are longer than in the corresponding M(η5-P5)+ by 0.28-0.38 Å. The M(η5-P5)+ complexes may be tighter binding with the shorter metal-ring distances, the possible reason is that there being stronger metal-ring π interactions in M(η5-P5)+ than in M(η5-P5)2, even though latter satisfies the 18-electron rule. The electron densities are found to accumulate at the metal centers, this novel situation may have an impact on the mechanism of some potential catalysis reactions.

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