scholarly journals Response to Comment on “Insulator-metal transition in dense fluid deuterium”

Science ◽  
2019 ◽  
Vol 363 (6433) ◽  
pp. eaaw1970 ◽  
Author(s):  
Peter M. Celliers ◽  
Marius Millot ◽  
Stephanie Brygoo ◽  
R. Stewart McWilliams ◽  
Dayne E. Fratanduono ◽  
...  
Keyword(s):  
First Principles ◽  
Temperature Drop ◽  
First Principles Calculations ◽  
Small Temperature ◽  
Isentropic Compression ◽  
First Order ◽  
Original Estimate ◽  
Insulator Metal Transition ◽  
Dense Fluid

In their comment, Desjarlais et al. claim that a small temperature drop occurs after isentropic compression of fluid deuterium through the first-order insulator-metal transition. We show that their calculations do not correspond to the experimental thermodynamic path, and that thermodynamic integrations with parameters from first-principles calculations produce results in agreement with our original estimate of the temperature drop.

scholarly journals Comment on “Insulator-metal transition in dense fluid deuterium”

Science ◽  
2019 ◽  
Vol 363 (6433) ◽  
pp. eaaw0969 ◽  
Author(s):  
Michael P. Desjarlais ◽  
Marcus D. Knudson ◽  
Ronald Redmer
Keyword(s):  
Specific Heat ◽  
First Principles ◽  
First Principles Calculations ◽  
Temperature Analysis ◽  
Insulator Metal Transition ◽  
Dense Fluid

Celliers et al. (Reports, 17 August 2018, p. 677), in an attempt to reconcile differences in inferred metallization pressures, provide an alternative temperature analysis of the Knudson et al. experiments (Reports, 26 June 2015, p. 1455). We show that this reanalysis implies an anomalously low specific heat for the metallic fluid that is clearly inconsistent with first-principles calculations.

STRUCTURAL AND MAGNETIC PHASE TRANSITIONS OF BiFeO3 INDUCED BY PRESSURE

2013 ◽  
Vol 06 (03) ◽  
pp. 1350026 ◽  
Author(s):  
HONG-JIAN FENG ◽  
XIAOYUN HU ◽  
HUIJUAN CHEN
Keyword(s):  
Phase Transitions ◽  
First Principles ◽  
Magnetic Phase ◽  
Structural Phase ◽  
Orthorhombic Phase ◽  
Magnetic Phase Transitions ◽  
Ferromagnetic Transition ◽  
First Principles Calculations ◽  
First Order ◽  
Pressure Region

First-principles calculations on BiFeO3 under low-pressure region show that the rhombohedral-monoclinic and rhombohedral-orthorhombic phase transitions can be found around the critical pressure value, ~9 GPa.We suggest that the structure involve the combination of these three phases and change to the pure orthorhombic phase gradually as pressure is beyond the critical value. Moreover, it is a first-order structural phase transition, accompanied with antiferromagnetic–ferromagnetic transition.

Structural, Electronic, Elastic and Mechanical Properties of ScNi, ScPd and ScPt: A FP-LAPW Study

2014 ◽  
Vol 1047 ◽  
pp. 27-34 ◽  
Author(s):  
Bushra Fatima ◽  
Sunil Singh Chouhan ◽  
Nikita Acharya ◽  
S.P. Sanyal
Keyword(s):  
Mechanical Properties ◽  
Band Structure ◽  
Bulk Modulus ◽  
Ground State ◽  
First Principles ◽  
First Principles Calculations ◽  
Fermi Surfaces ◽  
First Order ◽  
Cauchy Pressure ◽  
Metallic Bonding

Systematic first principles calculations have been carried out to study the structural, electronic, elastic and mechanical properties of ScNi, ScPd and ScPt using FP-LAPW method within GGA. The ground state properties such as lattice constant, bulk modulus and first order pressure derivates of bulk modulus, were evaluated. The electronic and bonding patterns of these compounds have been analysed quantitatively from band structure and Fermi surfaces. It is clear from band structures that these compounds are metallic in nature. Ductility for these compounds is analysed by using Pugh’s criteria, Cauchy pressure (C12–C44) and Frantsevich rule. Amongst all these Sc compounds, ScNi is found to be most ductile due to the presence of strong metallic bonding.

First order transition in Dy5Si3Ge: Transport and thermal properties, and first principles calculations

2011 ◽  
Vol 109 (7) ◽  
pp. 07A923 ◽  
Author(s):  
R. Nirmala ◽  
Durga Paudyal ◽  
V. K. Pecharsky ◽  
K. A. Gschneidner ◽  
A. K. Nigam
Keyword(s):  
Thermal Properties ◽  
First Principles ◽  
Order Transition ◽  
First Principles Calculations ◽  
First Order ◽  
First Order Transition

NMR and Computational Studies of Ba8Ga16Sn30 Clathrates

2010 ◽  
Vol 1267 ◽  
Author(s):  
Sergio Yanuen Rodriguez ◽  
Xiang Zheng ◽  
Laziz Saribaev ◽  
Joseph H Ross
Keyword(s):  
Bond Length ◽  
Electron Microprobe ◽  
First Principles ◽  
Type I ◽  
Computational Studies ◽  
First Principles Calculations ◽  
Broad Resonance ◽  
Type Viii ◽  
First Order ◽  
Atomic Displacements

AbstractWe have synthesized type-VIII and type-I Ba8Ga16Sn30 clathrates by using different annealing treatments, confirmed with XRD and electron microprobe measurements. NMR lineshape measurements identified a broad resonance corresponding to first-order-shifted satellites. Simulations for the type I structure based on first principles calculations provided an excellent fit to the data, with the best agreement provided by the calculated lowest-energy configuration, having no Ga-Ga bonds. These results allow us to address local configurations within the random type-I alloy, as well as atomic displacements and bond-length distributions, which we compare to experiment.

Electronic Structure and X-ray Absorption Spectra of Rutile TiO2 Using First-Principles Calculations

2014 ◽  
Vol 52 (12) ◽  
pp. 1025-1029
Author(s):  
Min-Wook Oh ◽  
Tae-Gu Kang ◽  
Byungki Ryu ◽  
Ji Eun Lee ◽  
Sung-Jae Joo ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Absorption Spectra ◽  
First Principles ◽  
First Principles Calculations ◽  
Rutile Tio2 ◽  
X Ray ◽  
X Ray Absorption

To Bend or Not to Bend, the Dilemma of Multiple Bonds

2019 ◽  
Author(s):  
Michele Pizzocchero ◽  
Matteo Bonfanti ◽  
Rocco Martinazzo
Keyword(s):  
First Principles ◽  
2D Materials ◽  
Main Group ◽  
First Principles Calculations ◽  
Group 14 ◽  
Multiple Bonds ◽  
Main Group Elements ◽  
Structural Distortions

The manuscript addresses the issue of the structural distortions occurring at multiple bonds between high main group elements, focusing on group 14. These distortions are known as trans-bending in silenes, disilenes and higher group analogues, and buckling in 2D materials likes silicene and germanene. A simple but correlated \sigma + \pi model is developed and validated with first-principles calculations, and used to explain the different behaviour of second- and higher- row elements.

Thermodynamic Stability of Hexagonal and Rhombohedral Bn at Cvd Conditions from Van der Waals Corrected First Principles Calculations

2019 ◽  
Author(s):  
Henrik Pedersen ◽  
Björn Alling ◽  
Hans Högberg ◽  
Annop Ektarawong
Keyword(s):  
Thin Films ◽  
Thermodynamic Stability ◽  
First Principles ◽  
Thermal Equilibrium ◽  
Density Functional ◽  
Van Der Waals ◽  
Chemical Vapor ◽  
First Principles Calculations ◽  
Functional Theory ◽  
The Stability

Thin films of boron nitride (BN), particularly the sp<sup>2</sup>-hybridized polytypes hexagonal BN (h-BN) and rhombohedral BN (r-BN) are interesting for several electronic applications given band gaps in the UV. They are typically deposited close to thermal equilibrium by chemical vapor deposition (CVD) at temperatures and pressures in the regions 1400-1800 K and 1000-10000 Pa, respectively. In this letter, we use van der Waals corrected density functional theory and thermodynamic stability calculations to determine the stability of r-BN and compare it to that of h-BN as well as to cubic BN and wurtzitic BN. We find that r-BN is the stable sp<sup>2</sup>-hybridized phase at CVD conditions, while h-BN is metastable. Thus, our calculations suggest that thin films of h-BN must be deposited far from thermal equilibrium.

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