Periodic Hartree–Fock and hybrid density functional calculations on the metallic and the insulating phase of (EDO-TTF)2PF6

2015 ◽  
Vol 17 (45) ◽  
pp. 30371-30377 ◽  
Author(s):  
Gerrit-Jan Linker ◽  
Paul H. M. van Loosdrecht ◽  
Piet Th. van Duijnen ◽  
Ria Broer
Keyword(s):  
Phase Transition ◽  
Quantum Chemical ◽  
Density Functional ◽  
Electronic Band ◽  
Metal Insulator ◽  
Hartree Fock ◽  
Insulator Phase Transition ◽  
Insulating Phase ◽  
Electronic Band Structures ◽  
Hybrid Density Functional

Electronic band structures obtained from quantum chemical calculations are used to discuss the metal–insulator phase transition in (EDO-TTF)2PF6 in terms of a Peierls mechanism.

A Study of Reactivity of Model Compounds of Lignin Biopolymer

2021 ◽  
Vol 316 ◽  
pp. 75-80
Author(s):  
Oleg Kh. Karimov ◽  
Galina Yu. Kolchina ◽  
Eldar M. Movsumzade
Keyword(s):  
Aromatic Ring ◽  
Quantum Chemical ◽  
Density Functional ◽  
Nucleophilic Attack ◽  
Hydroxyl Group ◽  
Model Compounds ◽  
Hartree Fock ◽  
Quantitative Characteristics ◽  
Derivatives Of ◽  
Hybrid Density Functional

In the framework of method of the B3LYP hybrid density functional and the restricted Hartree-Fock method, quantum-chemical calculations of model compounds of lignin, i.e. derivatives of p-hydroxycinnamic alcohol were carried out. The structures and reactivity of coumaric, coniferyl and synapol alcohols were studied. Quantitative characteristics of the reactivity of these acids are given. It is found that the electronic structure of lignin is determined primarily by the charge distribution in its structural phenylpropane unit. In the molecules of all model compounds of lignin, the center for nucleophilic attack is the carbon of aromatic ring (E-ring) with a hydroxyl group, and in the molecule of synapol alcohol, this center is also the carbon of the aromatic ring (E-ring) with a methoxy group. In all three compounds, a center with an increased electron density appears on the Сβ carbon atom.

The character of metal-insulator phase transition in V2O3 from the plasmon behaviour

1983 ◽  
Vol 48 (5) ◽  
pp. 471-474 ◽  
Author(s):  
S Stizza ◽  
I Davoli ◽  
R Bernardini ◽  
A Bianconi ◽  
M Benfatto
Keyword(s):  
Phase Transition ◽  
Metal Insulator ◽  
Insulator Phase Transition

First-principles study on the heterostructure of twisted graphene/hexagonal boron nitride/graphene sandwich structure

2021 ◽  
Author(s):  
Yiheng Chen ◽  
Wen-Ti Guo ◽  
Zi-si Chen ◽  
Suyun Wang ◽  
Jian-Min Zhang
Keyword(s):  
Phase Transition ◽  
Boron Nitride ◽  
Charge Density ◽  
First Principles ◽  
Sandwich Structure ◽  
Hexagonal Boron Nitride ◽  
Mulliken Population ◽  
Metal Insulator ◽  
Insulator Phase Transition ◽  
Twisted Graphene

Abstract In recent years, the discovery of "magic angle" graphene has given new inspiration to the formation of heterojunctions. Similarly, the use of hexagonal boron nitride, known as white graphene, as a substrate for graphene devices has more aroused great interest in the graphene/hexagonal boron nitride (G/hBN) heterostructure system. Based on the first principles method of density functional theory, the band structure, density of states, Mulliken population, and differential charge density of a tightly packed model of twisted graphene/hexagonal boron nitride/graphene (G/hBN/G) sandwich structure have been studied. Through the establishment of heterostructure models TBG inserting hBN with different twisted angles, it was found that the band gap, Mulliken population, and charge density, exhibited specific evolution regulars with the rotation angle of the upper graphene, showing novel electronic properties and realizing metal-insulator phase transition. We find that the particular value of the twist angle at which the metal-insulator phase transition occurs and propose a rotational regulation mechanism with angular periodicity. Our results have guiding significance for the practical application of heterojunction electronic devices.

The metal-insulator phase transition in the strained GdBiTe3

2013 ◽  
Vol 113 (17) ◽  
pp. 17A934 ◽  
Author(s):  
Tran Van Quang ◽  
Miyoung Kim
Keyword(s):  
Phase Transition ◽  
Metal Insulator ◽  
Insulator Phase Transition

scholarly journals Magnetic field driven metal-insulator phase transition in planar systems

2002 ◽  
Vol 66 (4) ◽  
Author(s):  
E. V. Gorbar ◽  
V. P. Gusynin ◽  
V. A. Miransky ◽  
I. A. Shovkovy
Keyword(s):  
Magnetic Field ◽  
Phase Transition ◽  
Metal Insulator ◽  
Insulator Phase Transition ◽  
Planar Systems

Disappearance of the quasi-one-dimensional plasmon at the metal-insulator phase transition of indium atomic wires

2008 ◽  
Vol 77 (20) ◽  
Author(s):  
Canhua Liu ◽  
Takeshi Inaoka ◽  
Shin Yaginuma ◽  
Tomonobu Nakayama ◽  
Masakazu Aono ◽  
...  
Keyword(s):  
Phase Transition ◽  
Metal Insulator ◽  
One Dimensional ◽  
Atomic Wires ◽  
Insulator Phase Transition

Study of the phase transition properties and electronic band structures of VO2 thin films grown on different substrates

2018 ◽  
Vol 6 (2) ◽  
pp. 026409
Author(s):  
Yunfeng Guo ◽  
Yuzhi Zhang ◽  
Liangmiao Zhang ◽  
Xinrui Lv ◽  
Lingnan Wu ◽  
...  
Keyword(s):  
Thin Films ◽  
Phase Transition ◽  
Band Structures ◽  
Electronic Band ◽  
Vo2 Thin Films ◽  
Electronic Band Structures

First-principles investigation of the electronic band structures and optical properties of quaternary ABaMQ4 (A = Rb, Cs; M = P, V; and Q = S) metal chalcogenides

2018 ◽  
Vol 32 (30) ◽  
pp. 1850337
Author(s):  
Shahid Ullah ◽  
Hayat Ullah ◽  
Abdullah Yar ◽  
Sikander Azam ◽  
A. Laref
Keyword(s):  
Optical Properties ◽  
First Principles ◽  
Density Functional ◽  
Correlation Energy ◽  
Electronic Charge ◽  
Electromagnetic Spectrum ◽  
Metal Chalcogenides ◽  
Electronic Band ◽  
Charge Densities ◽  
Electronic Band Structures

In this paper, we study the optoelectronic properties of quaternary metal chalcogenide semiconductor ABaMQ4 (A = Rb, Cs; M = P, V; and Q = S) compounds using state-of-the-art density functional theory (DFT) with TB-mBJ approximation for the treatment of exchange-correlation energy. In particular, the electronic and optical properties of the relaxed geometries of these compounds are investigated. Our first-principles ab-initio calculations show that the CsBaPS4 and RbBaPS4 compounds have direct bandgaps whereas the CsBaVS4 compound exhibits indirect bandgap nature. Importantly, the theoretically calculated values of the bandgaps of the compounds are consistent with experiment. Furthermore, our analysis of the electronic charge densities of these compounds indicates that the above quaternary chalcogenides have mixed covalent and ionic bonding characters. The effective masses of these compounds are also calculated which provide very useful information about the band structure and transport characteristics of the investigated compounds. Similarly, high absorptivity in the visible and ultraviolet regions of the electromagnetic spectrum possibly predicts and indicates the importance of these materials for potential optoelectronic applications in this range.

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