First-Principles Calculations in Real-Space Formalism

10.1142/p370 ◽  
2005 ◽  
Author(s):  
Kikuji Hirose ◽  
Tomoya Ono ◽  
Yoshitaka Fujimoto ◽  
Shigeru Tsukamoto
Keyword(s):  
First Principles ◽  
Real Space ◽  
First Principles Calculations ◽  
Space Formalism

Quantum Calculations of Carbon Nanotube Charging and Capacitance

2003 ◽  
Vol 789 ◽  
Author(s):  
Pawel Pomorski ◽  
Lars Pastewka ◽  
Christopher Roland ◽  
Hong Guo ◽  
Jian Wang
Keyword(s):  
Carbon Nanotube ◽  
First Principles ◽  
Density Functional ◽  
Real Space ◽  
Aluminum Surface ◽  
First Principles Calculations ◽  
Armchair Nanotubes ◽  
Real Material ◽  
Greens Function ◽  
Capacitance Matrix

ABSTRACTAlthough it has long been known that the classical notions of capacitance are altered at the nanoscale, few first principles calculations of these properties exist for real material systems. With a recently developed ab initio formalism, which combines nonequilibrium Greens function techniques with real-space density functional calculations, we have investigated charging effects for carbon nanotube systems, which are described by the capacitance coefficients. Specifically, the capacitance matrix of two nested nanotube armchair nanotubes, the insertion of one nanotube into another, and the properties of a nanotube acting as a probe over a flat aluminum surface were considered.

scholarly journals The Electronic Structure of Grain Boundaries in NB

1990 ◽  
Vol 209 ◽  
Author(s):  
Erik C. Sowa ◽  
A. Gonis ◽  
X. -G. Zhang
Keyword(s):  
Electronic Structure ◽  
Grain Boundary ◽  
Grain Boundaries ◽  
Multiple Scattering ◽  
First Principles ◽  
Scattering Theory ◽  
Real Space ◽  
First Principles Calculations ◽  
Densities Of States ◽  
Local Densities

ABSTRACTWe present first-principles calculations of the electronic structure of Nb grain boundaries. These are the first such calculations for a bcc metal using the real-space multiple-scattering theory (RSMST). Local densities of states near a Σ5 twist grain boundary are compared to those for bulk Nb.

scholarly journals Thermionic transport across gold-graphene-WSe2 van der Waals heterostructures

2019 ◽  
Vol 5 (11) ◽  
pp. eaax7827 ◽  
Author(s):  
Md Golam Rosul ◽  
Doeon Lee ◽  
David H. Olson ◽  
Naiming Liu ◽  
Xiaoming Wang ◽  
...  
Keyword(s):  
First Principles ◽  
Van Der Waals ◽  
Electrical Conductance ◽  
Electrical Energy ◽  
Real Space ◽  
Electronic Cooling ◽  
Cooling Curve ◽  
Hybrid Technique ◽  
First Principles Calculations ◽  
Theoretical Predictions

Solid-state thermionic devices based on van der Waals structures were proposed for nanoscale thermal to electrical energy conversion and integrated electronic cooling applications. We study thermionic cooling across gold-graphene-WSe2-graphene-gold structures computationally and experimentally. Graphene and WSe2 layers were stacked, followed by deposition of gold contacts. The I-V curve of the structure suggests near-ohmic contact. A hybrid technique that combines thermoreflectance and cooling curve measurements is used to extract the device ZT. The measured Seebeck coefficient, thermal and electrical conductance, and ZT values at room temperatures are in agreement with the theoretical predictions using first-principles calculations combined with real-space Green’s function formalism. This work lays the foundation for development of efficient thermionic devices.

Electron localization on dislocations in metals: Real-space first-principles calculations

2001 ◽  
Vol 64 (13) ◽  
Author(s):  
O. Yu. Kontsevoi ◽  
Yu. N. Gornostyrev ◽  
O. N. Mryasov ◽  
A. J. Freeman ◽  
M. I. Katsnelson ◽  
...  
Keyword(s):  
First Principles ◽  
Real Space ◽  
Electron Localization ◽  
First Principles Calculations

The Electronic Structure pf Σ5 Grain Boundaries in CU

1989 ◽  
Vol 159 ◽  
Author(s):  
Erik C. Sowa ◽  
A. Gonis ◽  
X.-G. Zhang
Keyword(s):  
Electronic Structure ◽  
Grain Boundaries ◽  
First Principles ◽  
Real Space ◽  
Embedded Atom Method ◽  
First Principles Calculations ◽  
Bulk Materials ◽  
Embedded Atom ◽  
Densities Of States ◽  
Self Consistent

ABSTRACTWe present first-principles calculations of the densities of states (DOS's) of unrelaxed and relaxed twist and tilt grain boundaries (GB's) in Cu. The relaxed configurations were obtained through the use of the Embedded Atom Method (EAM), while the DOS's were calculated using the real-space multiplescattering theory (RSMST) approach recently introduced in the literature. The DOS's of GB's are compared against those of bulk materials as well as against one another. Although the RSMST calculations are still not self-consistent, these comparisons allow us to verify certain expected trends in the DOS's, and to verify the usefulness and reliability of our method.

scholarly journals First principles modeling of pure black phosphorus devices under pressure

2019 ◽  
Vol 10 ◽  
pp. 1943-1951 ◽  
Author(s):  
Ximing Rong ◽  
Zhizhou Yu ◽  
Zewen Wu ◽  
Junjun Li ◽  
Bin Wang ◽  
...  
Keyword(s):  
First Principles ◽  
Pressure Ratio ◽  
Electronic Devices ◽  
Pressure Sensors ◽  
Real Space ◽  
Black Phosphorus ◽  
First Principles Calculations ◽  
Out Of Plane ◽  
Band Alignments ◽  
Low Dimensional

Black phosphorus (BP) has a pressure-dependent bandgap width and shows the potential for applications as a low-dimensional pressure sensor. We built two kinds of pure BP devices with zigzag or armchair conformation, and explored their pressure-dependent conductance in detail by using first principles calculations. The zigzag BP devices and the armchair BP devices exhibit different conductance–pressure relationships. For the zigzag BP devices conductance is robust against stress when the out-of-plane pressure ratio is less than 15%, and then increases rapidly until the conductive channels are fully opened. For the armchair pure BP devices conductance decreases at first by six orders of magnitude under increasing pressure and then increases quickly with further increase of pressure until the devices enter the on-state. This shows that the pure zigzag BP devices are more suitable for the application as flexible electronic devices with almost constant conductance under small pressure, while armchair BP devices can serve as bidirectional pressure sensors. Real-space distributions of band alignments were explored to understand the different pressure-related properties. We fitted a set of parameters based on the results from the empirical Wentzel–Kramers–Brillouin method, which provides an effortless approximation to quantitatively predict the pressure-related behaviors of large pure BP devices.

Real-space pseudopotential method for first principles calculations of general periodic and partially periodic systems

2008 ◽  
Vol 78 (7) ◽  
Author(s):  
Amir Natan ◽  
Ayelet Benjamini ◽  
Doron Naveh ◽  
Leeor Kronik ◽  
Murilo L. Tiago ◽  
...  
Keyword(s):  
First Principles ◽  
Real Space ◽  
Pseudopotential Method ◽  
Periodic Systems ◽  
First Principles Calculations

Electronic Structure and X-ray Absorption Spectra of Rutile TiO2 Using First-Principles Calculations

2014 ◽  
Vol 52 (12) ◽  
pp. 1025-1029
Author(s):  
Min-Wook Oh ◽  
Tae-Gu Kang ◽  
Byungki Ryu ◽  
Ji Eun Lee ◽  
Sung-Jae Joo ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Absorption Spectra ◽  
First Principles ◽  
First Principles Calculations ◽  
Rutile Tio2 ◽  
X Ray ◽  
X Ray Absorption
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