Interatomic Potentials From First-Principles Calculations

1992 ◽  
Vol 291 ◽  
Author(s):  
Furio Ercolessi ◽  
James B. Adams

ABSTRACTWe propose a new scheme to extract “optimal” interatomic potentials starting from a large number of atomic configurations (and their forces) obtained from first-principles calculations. The method appears to be able to overcome the difficulties encountered by traditional fitting approaches when using rich and complex analytical forms, and constitute a step forward towards large-scale simulations of condensed matter systems with a degree of accuracy comparable to that obtained by ab initio methods. A first exploratory application to aluminum is presented.

1993 ◽  
Vol 321 ◽  
Author(s):  
C. Molteni ◽  
L. Colombo ◽  
L. Miglio

ABSTRACTWe investigate the short-range structural properties of a-GaAs as obtained in a computer experiment based on a tight-binding molecular dynamics simulation. The amorphous configuration is obtained by quenching a liquid sample well equilibrated at T=1600 K. A detailed characterization of the topology and defect distribution of the amorphous network is presented and discussed. The electronic structure of our sample is calculated as well. Finally, we discuss the reliability and transferability of the present computational scheme for large-scale simulations of compound semiconductor materials by comparing our results to first-principles calculations.


2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Fei Wang ◽  
Xuepeng Wang ◽  
Yi-Fan Zhao ◽  
Di Xiao ◽  
Ling-Jie Zhou ◽  
...  

AbstractThe Berry phase picture provides important insights into the electronic properties of condensed matter systems. The intrinsic anomalous Hall (AH) effect can be understood as the consequence of non-zero Berry curvature in momentum space. Here, we fabricate TI/magnetic TI heterostructures and find that the sign of the AH effect in the magnetic TI layer can be changed from being positive to negative with increasing the thickness of the top TI layer. Our first-principles calculations show that the built-in electric fields at the TI/magnetic TI interface influence the band structure of the magnetic TI layer, and thus lead to a reconstruction of the Berry curvature in the heterostructure samples. Based on the interface-induced AH effect with a negative sign in TI/V-doped TI bilayer structures, we create an artificial “topological Hall effect”-like feature in the Hall trace of the V-doped TI/TI/Cr-doped TI sandwich heterostructures. Our study provides a new route to create the Berry curvature change in magnetic topological materials that may lead to potential technological applications.


2019 ◽  
Vol 4 (2) ◽  
pp. 37 ◽  
Author(s):  
Jelena Pešić ◽  
Igor Popov ◽  
Andrijana Šolajić ◽  
Vladimir Damljanović ◽  
Kurt Hingerl ◽  
...  

Magnesium diboride gained significant interest in the materials science community after the discovery of its superconductivity, with an unusually high critical temperature of 39 K. Many aspects of the electronic properties and superconductivity of bulk MgB 2 and thin sheets of MgB 2 have been determined; however, a single layer of MgB 2 has not yet been fully theoretically investigated. Here, we present a detailed study of the structural, electronic, vibrational, and elastic properties of monolayer MgB 2 , based on ab initio methods. First-principles calculations reveal the importance of reduction of dimensionality on the properties of MgB 2 and thoroughly describe the properties of this novel 2D material. The presence of a negative Poisson ratio, higher density of states at the Fermi level, and a good dynamic stability under strain make the MgB 2 monolayer a prominent material, both for fundamental research and application studies.


1994 ◽  
Vol 357 ◽  
Author(s):  
M. W. Finnis ◽  
C. Kruse ◽  
U. SchÖnberger

AbstractWe discuss the recent first principles calculations of the properties of interfaces between metals and oxides. This type of calculation is parameter-free, and exploits the density functional theory in the local density approximation to obtain the electronic structure of the system. At the same time the equilibrium atomic structure is sought, which minimises the excess energy of the interface. Up to now calculations of this type have been made for a few model interfaces which are atomically coherent, that is with commensurate lattices. Examples are Ag/MgO and Nb/Al2O3. In these cases it has been possible to predict the structures observed by high resolution electron microscopy. The calculations are actually made in a supercell geometry, in which there are alternating nanolayers of metal and ceramic. Because of the effectiveness of metallic screening in particular, the interfaces between the nanolayers do not interfere much with each other.Besides the electronic structure of the interface, such calculations have provided values of the ideal work of adhesion. Electrostatic image forces in conjunction with the elementary ionic model provide a simple framework for understanding the results.An important role of such calculations is to develop intuition about the nature of the bonding, including the effects of charge transfer, which has formerly only been described in an empirical way. It may then be possible to build atomistic models of the metal/ceramic interaction which have a sound physical basis and can be calibrated against ab initio results. Simpler models are necessary if larger systems, including misfit dislocations and other defects, are to be simulated, with a view to understanding the atomic processes of growth and failure. Another area in which ab initio calculations can be expected to contribute is in the chemistry of impurity segregation and its effect at interfaces. Such theoretical tools are a natural partner to the experimental technique of high resolution electron energy loss spectroscopy for studying the local chemical environment at an interface.


2003 ◽  
Author(s):  
S. V. Piskunov ◽  
R. A. Evarestov ◽  
Eugene A. Kotomin ◽  
R. I. Eglitis ◽  
G. Borstel

2014 ◽  
Vol 16 (19) ◽  
pp. 8935-8939 ◽  
Author(s):  
Jahyun Koo ◽  
Minwoo Park ◽  
Seunghyun Hwang ◽  
Bing Huang ◽  
Byungryul Jang ◽  
...  

Functionalization of graphdiyne, a two-dimensional atomic layer of sp–sp2 hybrid carbon networks, was investigated through first-principles calculations.


Domain Walls ◽  
2020 ◽  
pp. 36-75
Author(s):  
J. Íñiguez

This chapter discusses representative first-principles studies of structural domain walls in ferroics, focusing on the compounds that have received most attention by the simulations community so far: perovskite oxides. It describes in some detail a reduced number of case studies that come handy to illustrate different effects and to highlight the added value of the first-principles investigations. As regards the simulation methods, the chapter focuses on applications of density functional theory (DFT), typically employing an approximation for an effective treatment of ionic cores. A discussion on the application to domain-wall problems of first-principles-based methods for large-scale simulations of ferroelectrics and ferroelastics is also included. Finally, this chapter briefly on the opportunities and challenges for first-principles research in this field.


2015 ◽  
Vol 30 (3) ◽  
pp. 588-598 ◽  
Author(s):  
C. Hogan ◽  
F. Da Pieve

First principles calculations explain the presence, colour, and photo-reactivity of Hg-containing compounds involved in vermilion degradation.


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