scholarly journals Benchmarking density functional tight binding models for barrier heights and reaction energetics of organic molecules

2017 ◽  
Vol 38 (25) ◽  
pp. 2171-2185 ◽  
Author(s):  
Maja Gruden ◽  
Ljubica Andjeklović ◽  
Akkarapattiakal Kuriappan Jissy ◽  
Stepan Stepanović ◽  
Matija Zlatar ◽  
...  
Keyword(s):  
Density Functional ◽  
Organic Molecules ◽  
Tight Binding ◽  
Barrier Heights ◽  
Binding Models

MODELING VIBRATIONAL SPECTRA USING THE SELF-CONSISTENT CHARGE DENSITY-FUNCTIONAL TIGHT-BINDING METHOD II: INFRARED SPECTRA

2005 ◽  
Vol 04 (spec01) ◽  
pp. 639-655 ◽  
Author(s):  
HENRYK A. WITEK ◽  
KEIJI MOROKUMA ◽  
ANNA STRADOMSKA
Keyword(s):  
Charge Density ◽  
Infrared Spectra ◽  
Density Functional ◽  
Organic Molecules ◽  
Tight Binding ◽  
Additional Term ◽  
Functional Theory ◽  
Molecular Electron ◽  
Self Consistent ◽  
Energy Formula

We present an extended self-consistent charge density-functional tight-binding (SCC-DFTB) method that allows for computing vibrational infrared spectra. The extension is based on introducing an additional term in the SCC-DFTB energy formula that describes effectively the interaction of external electric field with molecular electron density distribution. The extended SCC-DFTB method is employed to model vibrational infrared spectra of 16 organic molecules. The calculated spectra are compared to experiment and to spectra obtained with density functional theory. For most of the molecules, the SCC-DFTB method reproduces the experimental spectra in a very satisfactory manner. We discuss the drawbacks and possible applications of this new scheme.

Tight-binding models and density-functional theory

1989 ◽  
Vol 39 (17) ◽  
pp. 12520-12536 ◽  
Author(s):  
W. Matthew C. Foulkes ◽  
Roger Haydock
Keyword(s):  
Density Functional Theory ◽  
Density Functional ◽  
Tight Binding ◽  
Functional Theory ◽  
Binding Models

Dynamic Simulation of the Migration of Oxygen Vacancy Defects in Rutile TiO2

2012 ◽  
Vol 1430 ◽  
Author(s):  
Jan M. Knaup ◽  
Michael Wehlau ◽  
Thomas Frauenheim
Keyword(s):  
Oxygen Vacancy ◽  
Dynamic Simulation ◽  
Electric Fields ◽  
Density Functional ◽  
Diffusion Processes ◽  
Tight Binding ◽  
Dynamic Simulations ◽  
Vacancy Defects ◽  
Barrier Heights ◽  
Large Dielectric Constant

ABSTRACTWe simulate the thermodynamics and kinetics of the drift/diffusion of oxygen vacancy defects in rutile TiO2, using the density-functional based tight-binding (DFTB) method. Both static and dynamic simulations have been performed. Results indicate that DFTB is well suited to examine the dynamic behavior of oxygen vacancies in TiO2. Detailed analysis shows, that strong model size dependence in relative diffusion barrier heights between different diffusion processes requires great care in defect diffusion simulations in TiO2. Thermodynamic results on the influence of an external electric field show that, due to the large dielectric constant, the coulomb driving force on oxygen vacancy diffusion is very small. Dynamic simulation of the influence of electric fields on the diffusion requires the use of advanced molecular dynamics acceleration schemes.

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