Determination of a Density Functional Tight Binding Model with an Extended Basis Set and Three-Body Repulsion for Carbon Under Extreme Pressures and Temperatures
Journal Article
·
· Journal of Physical Chemistry. C
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Physical and Life Sciences Directorate
- Pennsylvania State University, State College PA (United States). Department of Mechanical and Nuclear Engineering
- Univ. of Wisconsin, Madison, WI (United States). Department of Chemistry and Theoretical Chemistry Institute
- Karlsruhe Inst. of Technology (KIT) (Germany). Institute of Physical Chemistry
In this paper, we report here on development of a density functional tight binding (DFTB) simulation approach for carbon under extreme pressures and temperatures that includes an expanded basis set and an environmentally dependent repulsive energy. We find that including d-orbital interactions in the DFTB Hamiltonian improves determination of the electronic states at high pressure–temperature conditions, compared to standard DFTB implementations that utilize s- and p-orbitals only for carbon. We then determine a three-body repulsive energy through fitting to diamond, BC8, and simple cubic cold compression curve data, as well pressures from metallic liquid configurations from density functional theory (DFT) simulations. Our new model (DFTB-p3b) yields approximately 2 orders of magnitude increase in computational efficiency over standard DFT while retaining its accuracy for condensed phases of carbon under a wide range of conditions, including the metallic liquid phase at conditions up to 2000 GPa and 30 000 K. Finally, our results provide a straightforward method by which DFTB can be extended to studies of covalently bonded materials under extremely high pressures and temperatures such as the interiors of planets and other large celestial bodies.
- Research Organization:
- Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- USDOE National Nuclear Security Administration (NNSA)
- Grant/Contract Number:
- AC52-07NA27344
- OSTI ID:
- 1466147
- Report Number(s):
- LLNL-JRNL--608994; 709498
- Journal Information:
- Journal of Physical Chemistry. C, Journal Name: Journal of Physical Chemistry. C Journal Issue: 15 Vol. 117; ISSN 1932-7447
- Publisher:
- American Chemical SocietyCopyright Statement
- Country of Publication:
- United States
- Language:
- English
Similar Records
A Density Functional Tight Binding Model with an Extended Basis Set and Three-Body Repulsion for Hydrogen under Extreme Thermodynamic Conditions
Extending the Density Functional Tight Binding Method to Carbon Under Extreme Conditions
Density-Functional Tight-Binding Parameters for Bulk Zirconium: A Case Study for Repulsive Potentials
Journal Article
·
Mon Jun 23 20:00:00 EDT 2014
· Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory
·
OSTI ID:1466917
Extending the Density Functional Tight Binding Method to Carbon Under Extreme Conditions
Journal Article
·
Tue Nov 15 19:00:00 EST 2011
· Journal of Physical Chemistry. C
·
OSTI ID:1466116
Density-Functional Tight-Binding Parameters for Bulk Zirconium: A Case Study for Repulsive Potentials
Journal Article
·
Sun Feb 28 19:00:00 EST 2021
· Journal of Physical Chemistry. A, Molecules, Spectroscopy, Kinetics, Environment, and General Theory
·
OSTI ID:1777751