scholarly journals The elusive magnetic ground state of sodium superoxide (NaO2)

2021 ◽  
Author(s):  
Sarajit Biswas ◽  
Molly De Raychaudhury
Keyword(s):  
Ground State ◽  
First Principles ◽  
Alternative Energy ◽  
Density Functional ◽  
Structural Phase ◽  
Li Ion Batteries ◽  
Structural Phase Transitions ◽  
Magnetic Ground State ◽  
Functional Theory ◽  
Li Ion

Abstract An alternative energy storage solution to Li-ion batteries is a higher alkali metal superoxide, namely NaO2. It is well-known that the transport properties of this alkali superoxide are governed by the transfer of charge between O2 dimers. Although it goes through a plethora of structural phase transitions, its electronic and magnetic ground state remains shrouded. In this work, we perform first-principles density functional theory (DFT) calculations in order to understand the electronic structure, the source of the ‘unconventional’ magnetic properties and its effect on conductivity in Na superoxide. Finally, we explore the connection between magnetogyration and the magnetic ground state of NaO2 remaining undetected till date.

Structural Phase Transition and Electronic Properties of MgCe under High Pressure from First-Principles Calculations

2014 ◽  
Vol 577 ◽  
pp. 102-107
Author(s):  
Qiu Xiang Liu ◽  
De Ping Lu ◽  
Rui Jun Zhang ◽  
Lei Lu ◽  
Shi Fang Xie
Keyword(s):  
Phase Transition ◽  
Ground State ◽  
First Principles ◽  
Electronic Structures ◽  
Density Functional ◽  
High Pressures ◽  
Local Density ◽  
Structural Phase ◽  
First Principles Calculations ◽  
Functional Theory

The structural stability of MgCe under high pressures has been investigated by using the first-principles plane-wave pseudopotential density functional theory within the local density approximation (LDA). The obtained results predict that MgCe in the Ba structure is predicted to be the most stable structure corresponding to the ground state, because of lowest total energy. MgCe undergoes a pressure-induced phase transition from the Ba structure to B32 structure at 36 GPa. And no further transition is found up to 120 GPa. In addition, the electronic structures of four structures of MgCe are also calculated and discussed.

scholarly journals First-Principles Study of the Structural Stability and Dynamic Properties of Li2MSiO4 (M = Mn, Co, Ni) Polymorphs

Energies ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 224 ◽  
Author(s):  
Ponniah Vajeeston ◽  
Federico Bianchini ◽  
Helmer Fjellvåg
Keyword(s):  
Structural Stability ◽  
First Principles ◽  
Density Functional ◽  
Mechanical Stability ◽  
Dynamic Properties ◽  
Structural Parameters ◽  
First Principles Calculations ◽  
Li Ion Batteries ◽  
Functional Theory ◽  
Li Ion

In recent years, the scientific community has shown an increasing interest in regards to the investigation of novel materials for the intercalation of lithium atoms, suitable for application as cathodes in the new generations of Li-ion batteries. Within this framework, we have computed the relative structural stability, the electronic structure, the elastic and dynamic properties of Li2MSiO4 compounds (M = Mn, Co, Ni) by means of first-principles calculations based on density functional theory. The so-obtained structural parameters of the examined phases are in agreement with previous reports. The energy differences between different polymorphs are found to be small, and most of these structures are dynamically stable. The band structures and density of states are computed to analyse the electronic properties and characterise the chemical bonding. The single crystal elastic constants are calculated for all the examined modifications, proving their mechanical stability. These Li2MSiO4 materials are found to present a ductile behaviour upon deformation. The diffusion coefficients of Li ions, calculated at room temperature for all the examined modifications, reveal a poor conductivity for this class of materials.

scholarly journals Application of DFT-based machine learning for developing molecular electrode materials in Li-ion batteries

RSC Advances ◽  
2018 ◽  
Vol 8 (69) ◽  
pp. 39414-39420 ◽  
Author(s):  
Omar Allam ◽  
Byung Woo Cho ◽  
Ki Chul Kim ◽  
Seung Soon Jang
Keyword(s):  
Machine Learning ◽  
Density Functional Theory ◽  
High Throughput Screening ◽  
Density Functional ◽  
Electrode Materials ◽  
Screening Method ◽  
Li Ion Batteries ◽  
Functional Theory ◽  
Learning Framework ◽  
Li Ion

In this study, we utilize a density functional theory-machine learning framework to develop a high-throughput screening method for designing new molecular electrode materials.

scholarly journals London dispersion forces without density distortion: a path to first principles inclusion in density functional theory

2020 ◽  
Vol 224 ◽  
pp. 145-165
Author(s):  
Derk Pieter Kooi ◽  
Paola Gori-Giorgi
Keyword(s):  
Ground State ◽  
First Principles ◽  
Density Functional ◽  
Dispersion Forces ◽  
Density Functionals ◽  
Functional Theory ◽  
Exchange Correlation ◽  
State Densities ◽  
London Dispersion ◽  
London Dispersion Forces

We analyse a path to construct density functionals for the dispersion interaction energy from an expression in terms of the ground state densities and exchange–correlation holes of the isolated fragments.

Computational and Experimental investigation of Nalipoite-Li2APO4 (A = Na, K) electrolytes for Li-ion batteries

2015 ◽  
Vol 1740 ◽  
Author(s):  
G. F. Ortiz ◽  
M C. López ◽  
M.E. Arroyo-de Dompablo ◽  
José L. Tirado
Keyword(s):  
Energy Barrier ◽  
Density Functional ◽  
Ionic Mobility ◽  
First Principles Calculations ◽  
Li Ion Batteries ◽  
Ionic Conductors ◽  
Functional Theory ◽  
The Density Functional Theory ◽  
Li Ion ◽  
Calculated Energy Barrier

ABSTRACTThe potential ionic conductors Li2APO4 (A = Na, K) are investigated combining experiments and first principles calculations at the Density Functional Theory level. A high ionic conductivity of 6.5 x10−6 and 1.5 x10−5 S cm−1 at 25 and 70°C, respectively, is found in Nalipoite-Li2NaPO4. For this mixed phosphate the energy barriers to Li motion are calculated. The lower energy barrier (0.7 eV) implies the inter-chain diffusion of Li in the b-c plane. We predict that ionic mobility is enhanced in the isostructural Li2KPO4, with the lowest calculated energy barrier being 0.4 eV.

Ab Initio Electronic Structure Studies of CuO Multiferroics

2012 ◽  
Vol 488-489 ◽  
pp. 129-132 ◽  
Author(s):  
C. Kanagaraj ◽  
Baskaran Natesan
Keyword(s):  
First Principles ◽  
Density Functional ◽  
Electronic Band Structure ◽  
Metallic State ◽  
Magnetic Ground State ◽  
Electronic Band ◽  
Functional Theory ◽  
High Tc ◽  
Band Structure Calculations ◽  
Structure Calculations

We have performed detailed structural, electronic and magnetic properties of high - TC multiferroic CuO using first principles density functional theory. The total energy results revealed that AFM is the most stable magnetic ground state of CuO. The DOS and electronic band structure calculations show that in the absence of on-site Coulomb interaction (U), AFM structure of CuO heads to a metallic state. However, upon incorporating U in the calculations, a band gap of 1.2 eV is recovered. Furthermore, the Born effective charges calculated on Cu does not show any anomalous character.This suggests that the polarization seen in CuO could be attributed to the spin induced AFM ordering effect.

scholarly journals Fe–Si networks and charge/discharge-induced phase transitions in Li2FeSiO4 cathode materials

2018 ◽  
Vol 20 (21) ◽  
pp. 14557-14563 ◽  
Author(s):  
Xiaobao Lv ◽  
Xin Zhao ◽  
Shunqing Wu ◽  
Manh Cuong Nguyen ◽  
Zizhong Zhu ◽  
...  
Keyword(s):  
Phase Transitions ◽  
Cathode Materials ◽  
Electrode Materials ◽  
Structural Phase ◽  
Li Ion Batteries ◽  
Structural Phase Transitions ◽  
Li Ion ◽  
Charge Discharge

Structural phase transitions of electrode materials are responsible for poor reversibility during charge/discharge cycling in Li-ion batteries.

Metallic FeSe monolayer as an anode material for Li and non-Li ion batteries: a DFT study

2020 ◽  
Vol 22 (16) ◽  
pp. 8902-8912 ◽  
Author(s):  
Xiaodong Lv ◽  
Fengyu Li ◽  
Jian Gong ◽  
Jinxing Gu ◽  
Shiru Lin ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Electrochemical Performance ◽  
Lithium Ion Batteries ◽  
Anode Material ◽  
Density Functional ◽  
Lithium Ion ◽  
Li Ion Batteries ◽  
Functional Theory ◽  
Li Ion ◽  
Density Functional Theory Computations

By means of density functional theory computations, we explored the electrochemical performance of an FeSe monolayer as an anode material for lithium and non-lithium ion batteries (LIBs and NLIBs).

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