scholarly journals Density-Functional Tight-Binding Parameters for Bulk Zirconium: A Case Study for Repulsive Potentials

2021 ◽  
Vol 125 (10) ◽  
pp. 2184-2196
Author(s):  
Aulia Sukma Hutama ◽  
Chien-pin Chou ◽  
Yoshifumi Nishimura ◽  
Henryk A. Witek ◽  
Stephan Irle

2020 ◽  
Vol 16 (3) ◽  
pp. 1469-1481
Author(s):  
Néstor F. Aguirre ◽  
Amanda Morgenstern ◽  
M. J. Cawkwell ◽  
Enrique R. Batista ◽  
Ping Yang


2019 ◽  
Vol 43 (42) ◽  
pp. 16515-16523 ◽  
Author(s):  
Mohammad Qasemnazhand ◽  
Farhad Khoeini ◽  
Sima Shekarforoush

In this study, we first obtain the single-band tight-binding parameters of a B7 cluster in terms of matching the HOMO–LUMO levels obtained from density functional theory (DFT).



2019 ◽  
Author(s):  
Chiara Panosetti ◽  
Artur Engelmann ◽  
Lydia Nemec ◽  
Karsten Reuter ◽  
Johannes T. Margraf

The Density-Functional Tight Binding (DFTB) method is a popular semiempirical approximation to Density Functional Theory (DFT). In many cases, DFTB can provide comparable accuracy to DFT at a fraction of the cost, enabling simulations on length- and time-scales that are unfeasible with first principles DFT. At the same time (and in contrast to empirical interatomic potentials and force-fields), DFTB still offers direct access to electronic properties such as the band-structure. These advantages come at the cost of introducing empirical parameters to the method, leading to a reduced transferability compared to true first-principle approaches. Consequently, it would be very useful if the parameter-sets could be routinely adjusted for a given project. While fairly robust and transferable parameterization workflows exist for the electronic structure part of DFTB, the so-called repulsive potential Vrep poses a major challenge. In this paper we propose a machine-learning (ML) approach to fitting Vrep, using Gaussian Process Regression (GPR). The use of GPR circumvents the need for non-linear or global parameter optimization, while at the same time offering arbitrary flexibility in terms of the functional form. We also show that the proposed method can be applied to multiple elements at once, by fitting repulsive potentials for organic molecules containing carbon, hydrogen and oxygen. Overall, the new approach removes focus from the choice of functional form and parameterization procedure, in favour of a data-driven philosophy.



2018 ◽  
Vol 14 (5) ◽  
pp. 2341-2352 ◽  
Author(s):  
Julian J. Kranz ◽  
Maximilian Kubillus ◽  
Raghunathan Ramakrishnan ◽  
O. Anatole von Lilienfeld ◽  
Marcus Elstner


2020 ◽  
Vol 16 (4) ◽  
pp. 2181-2191 ◽  
Author(s):  
Chiara Panosetti ◽  
Artur Engelmann ◽  
Lydia Nemec ◽  
Karsten Reuter ◽  
Johannes T. Margraf


2011 ◽  
Vol 7 (7) ◽  
pp. 2262-2276 ◽  
Author(s):  
Sunandan Sarkar ◽  
Sougata Pal ◽  
Pranab Sarkar ◽  
A. L. Rosa ◽  
Th. Frauenheim


1997 ◽  
Vol 491 ◽  
Author(s):  
A. K. Mcmahan ◽  
J. E. Klepeis

ABSTRACTWe calculate ab initio values of tight-binding parameters for the /-electron metal Ce and various phases of Si, from local-density functional one-electron Hamiltonian and overlap matrix elements. Our approach allows us to unambiguously test the validity of the common minimal basis and two-center approximations as well as to determine the degree of transferability of both nonorthogonal and orthogonal hopping parameters in the cases considered.



2017 ◽  
Vol 23 (3) ◽  
Author(s):  
Jerome Cuny ◽  
Kseniia Korchagina ◽  
Chemseddine Menakbi ◽  
Tzonka Mineva


2019 ◽  
Author(s):  
Chiara Panosetti ◽  
Artur Engelmann ◽  
Lydia Nemec ◽  
Karsten Reuter ◽  
Johannes T. Margraf

The Density-Functional Tight Binding (DFTB) method is a popular semiempirical approximation to Density Functional Theory (DFT). In many cases, DFTB can provide comparable accuracy to DFT at a fraction of the cost, enabling simulations on length- and time-scales that are unfeasible with first principles DFT. At the same time (and in contrast to empirical interatomic potentials and force-fields), DFTB still offers direct access to electronic properties such as the band-structure. These advantages come at the cost of introducing empirical parameters to the method, leading to a reduced transferability compared to true first-principle approaches. Consequently, it would be very useful if the parameter-sets could be routinely adjusted for a given project. While fairly robust and transferable parameterization workflows exist for the electronic structure part of DFTB, the so-called repulsive potential Vrep poses a major challenge. In this paper we propose a machine-learning (ML) approach to fitting Vrep, using Gaussian Process Regression (GPR). The use of GPR circumvents the need for non-linear or global parameter optimization, while at the same time offering arbitrary flexibility in terms of the functional form. We also show that the proposed method can be applied to multiple elements at once, by fitting repulsive potentials for organic molecules containing carbon, hydrogen and oxygen. Overall, the new approach removes focus from the choice of functional form and parameterization procedure, in favour of a data-driven philosophy.



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