Structure of Hydrated Microporous Aluminophosphates:  Static and Molecular Dynamics Approaches of AlPO4-34 from First Principles Calculations

2002 ◽  
Vol 106 (34) ◽  
pp. 8599-8608 ◽  
Author(s):  
Guillaume Poulet ◽  
Philippe Sautet ◽  
Alain Tuel
Keyword(s):  
Molecular Dynamics ◽  
First Principles ◽  
First Principles Calculations

Discrete breathers modeling from first principles in graphene and in classical approximation in fcc Ni: Comparison

2019 ◽  
Vol 04 (02) ◽  
pp. 1950002 ◽  
Author(s):  
Ivan P. Lobzenko
Keyword(s):  
Molecular Dynamics ◽  
First Principles ◽  
High Frequency ◽  
Normal Modes ◽  
Nonlinear Normal Modes ◽  
First Principles Calculations ◽  
Discrete Breathers ◽  
Points Of View ◽  
Nonlinear Normal ◽  
Dynamics Simulations

Properties of discrete breathers are discussed from two points of view: (I) the ab initio modeling in graphene and (II) classical molecular dynamics simulations in the ace-centered cubic (fcc) Ni. In the first (I) approach, the possibility of exciting breathers depends on the strain applied to the graphene sheet. The uniaxial strain leads to opening the gap in the phonon band and, therefore, the existence of breathers with frequencies within the gap. In the second (II) approach, the structure of fcc Ni supports breathers of another kind, which possess a hard nonlinearity type. It is shown that particular high frequency normal mode can be used to construct the breather by means of overlaying a spherically symmetrical function, the maximum of which coincides with the breather core. The approach of breathers excitation based on nonlinear normal modes is independent of the level of approximation. Even though breathers could be obtained both in classical and first-principles calculations, each case has advantages and shortcomings, that are compared in the present work.

Preparation, Structure, And Electronic Properties Of Amorphous Gaas By Tight-Binding Molecular Dynamics

1993 ◽  
Vol 321 ◽  
Author(s):  
C. Molteni ◽  
L. Colombo ◽  
L. Miglio
Keyword(s):  
Molecular Dynamics ◽  
First Principles ◽  
Large Scale ◽  
Tight Binding ◽  
Computer Experiment ◽  
Dynamics Simulation ◽  
First Principles Calculations ◽  
Amorphous Network ◽  
Large Scale Simulations

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.

Peeling Silicene From Model Silver Substrates in Molecular Dynamics Simulations

2015 ◽  
Vol 82 (10) ◽  
Author(s):  
Zhao Qin ◽  
Zhiping Xu ◽  
Markus J. Buehler
Keyword(s):  
Molecular Dynamics ◽  
First Principles ◽  
Electronic Devices ◽  
Honeycomb Structure ◽  
Atomistic Simulations ◽  
Two Dimensional ◽  
First Principles Calculations ◽  
Semiconducting Properties ◽  
Silver Substrate ◽  
Dynamics Simulations

Silicene is a two-dimensional (2D) allotrope of silicon with a rippled or corrugated honeycomb structure in analogy to graphene. Its semiconducting properties make it attractive for developing future nano-electronic devices. However, it has been challenging to obtain its naked form by using a mechanical exfoliation method as what has been applied to graphene. Here, we use fully atomistic simulations with an effective potential for the silver substrate derived from first-principles calculations to investigate possible ways of peeling silicene solely by mechanical force. We find that the peeling direction is critical for exfoliating silicene and the peeling at a 45 deg angle with the substrate is the most efficient one to detach silicene. Our study could help to understand the mechanics of silicene on substrates and guide the technology of isolation of silicene from the substrate on which it is synthesized.

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