A STUDY OF CARBON NANOTUBES ENERGETICS USING ORBITAL FREE METHOD IN THE FRAME-WORK OF THE DENSITY FUNCTIONAL THEORY

2020 ◽  
Vol 7 (3) ◽  
pp. 29-36
Author(s):  
VICTOR ZAVODINSKY ◽  
◽  
OLGA GORKUSHA
Keyword(s):  
Density Functional Theory ◽  
Binding Energy ◽  
Density Functional ◽  
Tube Diameter ◽  
Tube Length ◽  
Functional Theory ◽  
The Third ◽  
The Density Functional Theory ◽  
Frame Work ◽  
Orbital Free

Dependence of the binding energy of carbon atoms in nanotubes on the tube diameter is studied. The full-electron orbital free modeling method, developed by us in the framework of the density functional theory, was used for calculation of the binding energy. Nanotubes of limited lengths with the armchair ends were investigated. The tube diameter D, was varied from 0,68 nm up to 1,50 nm; numbers of included atoms were changed from 80 up to 320. Three sets of tubes were studied: the tube length was 0,87 nm in the first set, 1,36 nm in second set, and 1,86 nm in the third set. For the first set the energy minimum (-7.50 eV) was found at Dmin = 1,22 nm, for the second set (-7.62 eV) at Dmin = 1.00 nm, and for the third set (-8.01 eV) at Dmin = 1.06 eV.

scholarly journals Dependence of Energy of Carbon Nanotubes on Tube Diameter: Orbital Free Simulations

2020 ◽  
Vol 4 (4) ◽  
Keyword(s):  
Experimental Data ◽  
Density Functional Theory ◽  
Binding Energy ◽  
Density Functional ◽  
Tube Diameter ◽  
Energy Minimum ◽  
Functional Theory ◽  
Electron Orbital ◽  
The Density Functional Theory ◽  
Orbital Free

A full-electron orbital free modeling method, developed in the framework of the density functional theory, was used for calculation of the binding energy. Nanotubes of limited lengths with the armchair ends were investigated. The tube diameter (D) was varied from 0.68 nm up to 1.50 nm; numbers of included atoms were changed from 80 up to 320. The binding energy minimum was found at D ≈ 1 nm in accordance with experimental data.

scholarly journals Interaction of sulfur with impurities in bcc iron

2021 ◽  
Vol 2103 (1) ◽  
pp. 012071
Author(s):  
A V Verkhovykh ◽  
A A Mirzoev ◽  
Yu K Okishev ◽  
N S Dyuryagina
Keyword(s):  
Density Functional Theory ◽  
Software Package ◽  
Density Functional ◽  
Functional Theory ◽  
The Third ◽  
Bcc Iron ◽  
The Density Functional Theory ◽  
Coordination Spheres ◽  
Strong Repulsion ◽  
Substitutional Impurities

Abstract In this work, the modeling of the sulfur interaction with substitutional impurities (Mn, P) and interstitial (C) has been carried out. All calculations were performed using the density functional theory in the WIEN2k software package. For the first two coordination spheres, there is a strong repulsion between carbon and sulfur, but in the third relative position, a slight attraction arises between the atoms. When sulfur interacts with manganese, attraction occurs only for the first coordination sphere, while the dissolution energy of both manganese and sulfur decreases. In the case of the S-P interaction, the binding energy is negative, and the dissolution energy of both sulfur and phosphorus decreases for all configurations, although the distance between phosphorus and sulfur increases. It can be assumed that the presence of phosphorus leads to the accumulation of sulfur in the material.

scholarly journals Adsorption Properties of Oxygen onH-Capped (5, 5) Boron Nitride Nanotube (BNNT)- A Density Functional Theory

2011 ◽  
Vol 8 (2) ◽  
pp. 609-614 ◽  
Author(s):  
Mohammad T. Baei ◽  
F. Kaveh ◽  
P. Torabi ◽  
S. Zahra Sayyad- Alangi
Keyword(s):  
Density Functional Theory ◽  
Binding Energy ◽  
Boron Nitride ◽  
Density Functional ◽  
Stable State ◽  
Adsorption Properties ◽  
Boron Nitride Nanotube ◽  
Vertical Orientation ◽  
Functional Theory ◽  
The Density Functional Theory

The density functional theory (DFT) has been used to simultaneously investigate physic/chemi-sorption properties of oxygen on the (5, 5) boron nitride nanotube (BNNT). Geometry optimizations were carried out at B3LYP/6-31G*level of theory using gaussian 98 suites of program. physisorption of O2outside the BNNT with a vertical orientation to the tube axis above a boron atom is the most stable state of physisorption and its binding energy is -0.775 kcal/mol. In the chemisorption of O2molecule, the most stable state is above two adjacent B and N atoms of a hexagon with a B-N bond length of 2.503 Å and the binding energy of adsorbed oxygen atoms -14.389 kcal/mol. Based on these results, We also provide the effects of O2adsorption on the electronic properties of BNNTs.

Assessing the Density Functional Theory in the Hydrogen Storage Problem

2008 ◽  
Vol 8 (6) ◽  
pp. 3091-3096 ◽  
Author(s):  
Giannis Mpourmpakis ◽  
George E. Froudakis
Keyword(s):  
Density Functional Theory ◽  
Binding Energy ◽  
Hydrogen Storage ◽  
Density Functional ◽  
Low Density ◽  
Theoretical Level ◽  
Density Region ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Storage Problem

A variety of high and low level ab-initio calculations have been performed to calculate hydrogen's physisorption binding energy on carbon nanotube's walls. This study focuses on the performance of several functionals on treating the H2-carbon nanotube interaction within the Density Functional Theory. Our results show that the behavior of the exchange functional in the low density region plays an important role in describing this weak van der Waals type of interaction. By comparing the binding energy values obtained on each theoretical level and interpreting the results in terms of %wt percentages of hydrogen storage using the Langmuir isotherms, we proposed possible ways to treat computationally the hydrogen storage problem within the DFT.

A quantum biochemistry investigation of willardiine partial agonism in AMPA receptors

2015 ◽  
Vol 17 (19) ◽  
pp. 13092-13103 ◽  
Author(s):  
José X. Lima Neto ◽  
Umberto L. Fulco ◽  
Eudenilson L. Albuquerque ◽  
Gilberto Corso ◽  
Eveline M. Bezerra ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Binding Energy ◽  
Ampa Receptor ◽  
Ampa Receptors ◽  
Density Functional ◽  
Functional Theory ◽  
Partial Agonism ◽  
The Density Functional Theory

We employ quantum biochemistry methods based on the Density Functional Theory (DFT) approach to unveil detailed binding energy features of willardiines co-crystallized with the AMPA receptor.

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