Extending the Domain of Application of Constrained Density Functional Theory to Large Molecular Systems

2020 ◽  
pp. 236-255
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Functional Theory ◽  
Molecular Systems

ATOMIC STRUCTURE STUDY OF THE Ag/MgO(100) SURFACE BY AN AB INITIO, TOTAL ENERGY MOLECULAR CLUSTER METHOD USING DENSITY FUNCTIONAL THEORY

1996 ◽  
Vol 03 (03) ◽  
pp. 1365-1375 ◽  
Author(s):  
LAURENT SPIESS
Keyword(s):  
Density Functional Theory ◽  
Total Energy ◽  
Ab Initio ◽  
Density Functional ◽  
Structure Study ◽  
Cluster Method ◽  
Molecular Cluster ◽  
Functional Theory ◽  
Molecular Systems ◽  
Coverage Dependence

The clean and Ag-covered MgO(100) surface is investigated by an all-electron, total energy, ab initio DMol molecular method (Density functional theory for Molecular systems). A large cluster of 100 atoms (including 50 oxygen and 50 magnesium) is built to represent the surface. A point charge embedding is used to investigate the electronic properties. The small relaxation of the surface, referred to as rumpling, is exhibited and shown to have barely no effect on the adsorption of Ag on the surface. The oxygen site is found to be the most stable for Ag atom adsorption, in good agreement with previous ab initio theoretical studies. The adsorption of a five-Ag-atom layer on the MgO(100) surface provides new and interesting results concerning the surface coverage dependence. We have used the unique ability of cluster methods to study the structural effects of the 3% mismatch at the Ag/MgO(100) interface, and we show that Ag atoms are likely to grow on the surface without epitaxy at low coverages.

An efficient density-functional-theory force evaluation for large molecular systems

2010 ◽  
Vol 133 (4) ◽  
pp. 044102 ◽  
Author(s):  
Simen Reine ◽  
Andreas Krapp ◽  
Maria Francesca Iozzi ◽  
Vebjørn Bakken ◽  
Trygve Helgaker ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Functional Theory ◽  
Molecular Systems

Non‐Born–Oppenheimer density functional theory of molecular systems

1982 ◽  
Vol 76 (1) ◽  
pp. 568-573 ◽  
Author(s):  
Joseph F. Capitani ◽  
Roman F. Nalewajski ◽  
Robert G. Parr
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Functional Theory ◽  
Molecular Systems

Assessing accuracy of exchange-correlation functionals for electron affinities

2017 ◽  
Vol 16 (06) ◽  
pp. 1750052 ◽  
Author(s):  
Katarzyna Pustuła ◽  
Marcin Makowski
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Electron Affinities ◽  
Functional Theory ◽  
Molecular Systems ◽  
Exchange Correlation ◽  
Large Improvement

The performance of exchange-correlation (xc) functionals for the description of electron affinities of atomic and molecular systems is investigated. A benchmark set is constructed and experimental adiabatic electron affinities are compared to Density Functional Theory (DFT) predictions. The results show that although good overall accuracy may be achieved from DFT-based approaches, there still exist outliers for any of the approximations applied. Apart from employing the standard DFT models, the possibility of the optimization of range-separated xc functionals has also been tested, however, no large improvement in accuracy is observed.

scholarly journals Efficient Linear-Scaling Density Functional Theory for Molecular Systems

2013 ◽  
Vol 9 (10) ◽  
pp. 4421-4427 ◽  
Author(s):  
Rustam Z. Khaliullin ◽  
Joost VandeVondele ◽  
Jürg Hutter
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Linear Scaling ◽  
Functional Theory ◽  
Molecular Systems

An ab initio and density functional theory study on neutral pterin radicals

Pteridines ◽  
2015 ◽  
Vol 26 (4) ◽  
pp. 135-142 ◽  
Author(s):  
Gilbert Reibnegger
Keyword(s):  
Density Functional Theory ◽  
Gas Phase ◽  
Electronic Structures ◽  
Density Functional ◽  
Electron System ◽  
Hydrogen Atoms ◽  
Functional Theory ◽  
Molecular Systems ◽  
Phase Water ◽  
Planar Transition

AbstractThe electronic structures of the five radicals resulting from homolytic elimination of one of the hydrogen atoms from the most stable tautomeric form of neutral pterin were investigated in gas phase as well as in aqueous solution. Molecular wave functions obtained by density functional theory were analysed by quantum theory of atoms in molecules and electron localisation functions (ELF). Spin densities of the radicals as well as electrostatic potential functions were analysed. Radicals resulting from elimination of N-bonded hydrogen atoms are more stable in comparison with radicals obtained after abstraction of C-bonded hydrogen atoms. N-centred radicals show strong delocalisation of spin density over both heteroaromatic rings; in C-centred radicals delocalisation does not occur. ELF analyses showed that in N-derived radicals particularly the lone electron pair at N2′ is strongly involved into the bicyclic heteroaromatic π-electron system. Thereby, bonding geometry at N2′ in these radicals changes from pyramidal to planar. Transition from gas phase to solution phase (water) generally leads to increased polarity of the structures. Pterin-derived free radicals have been implicated in several biologically important reactions; so this investigation provides first insights into the detailed electronic structures of such molecular systems.

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