Structural Phase Stability Studies on MBeH3(M = Li, Na, K, Rb, Cs) from Density Functional Calculations

2008 ◽  
Vol 47 (2) ◽  
pp. 508-514 ◽  
Author(s):  
P. Vajeeston ◽  
P. Ravindran ◽  
H. Fjellvåg
Keyword(s):  
Phase Stability ◽  
Density Functional Calculations ◽  
Density Functional ◽  
Structural Phase ◽  
Stability Studies

Correct Structural Phase Stability of FeS2, TiO2, and MnO2 from a Semilocal Density Functional

2021 ◽  
Vol 125 (7) ◽  
pp. 4284-4291
Author(s):  
Bikash Patra ◽  
Subrata Jana ◽  
Lucian A. Constantin ◽  
Prasanjit Samal
Keyword(s):  
Phase Stability ◽  
Density Functional ◽  
Structural Phase

scholarly journals Phase Stability in heavy f-Electron Metals from First-Principles Theory

2005 ◽  
Vol 893 ◽  
Author(s):  
Per Söderlind
Keyword(s):  
Phase Stability ◽  
Density Functional ◽  
Structural Phase ◽  
New Physics ◽  
Functional Theory ◽  
Higher Symmetry ◽  
Peierls Distortion ◽  
Breaking Mechanism ◽  
Ground State Structures ◽  
Volume Range

AbstractThe structural phase stability of heavy f-electron metals is studied by means of density-functional theory (DFT). These include temperature-induced transitions in plutonium metal as well as pressure-induced transitions in the trans-plutonium metals Am, Cm, Bk, and Cf. The early actinides (Th-Np) display phases that could be rather well understood from the competition of a crystal-symmetry breaking mechanism (Peierls distortion) of the 5f states and electrostatic forces, while for the trans-plutonium metals (Am-Cf) the ground-state structures are governed by 6d bonding. We show in this paper that new physics is needed to understand the phases of the actinides in the volume range of about 15-30 Å3. At these volumes one would expect, from theoretical arguments made in the past, to encounter highly complex crystal phases due to a Peierls distortion. Here we argue that the symmetry reduction associated with spin polarization can make higher symmetry phases competitive. Taking this into account, DFT is shown to describe the well-known phase diagram of plutonium and also the recently discovered complex and intriguing high-pressure phase diagrams of Am and Cm. The theory is further applied to investigate the behaviors of Bk and Cf under compression.

Phase Stability of Carbides and Nitrides in Steel

2006 ◽  
Vol 979 ◽  
Author(s):  
Marcel Sluiter
Keyword(s):  
Phase Stability ◽  
Density Functional Calculations ◽  
Density Functional ◽  
Great Influence ◽  
Alloyed Steel ◽  
Complex Structures ◽  
Atomic Size ◽  
Fundamental Level ◽  
Low Alloyed Steel

AbstractCarbides, nitrides, and carbonitrides have great influence on the properties of steel but are relatively little studied at a fundamental level: experimentally because of small dimensions of the precipitates and other difficulties, theoretically because of complex structures and poorly defined compositions. Modern density functional calculations reveal significant trends that can be partially summarized in terms of atomic size, carbon affinity, and hybridization de-magnetization concepts. Phase stability and order-disorder phenomena in widely occurring Cr-based M23C6 carbides and Mo-based M6C carbides are used to illustrate predictions relevant to low alloyed steel.

scholarly journals Hybrid-functional calculations of electronic structure and phase stability of MO (M = Zn, Cd, Be, Mg, Ca, Sr, Ba) and related ternary alloy MxZn1−xO

RSC Advances ◽  
2019 ◽  
Vol 9 (15) ◽  
pp. 8507-8514 ◽  
Author(s):  
Jinying Yu ◽  
Mingke Zhang ◽  
Zihan Zhang ◽  
Shangwei Wang ◽  
Yelong Wu
Keyword(s):  
Electronic Structure ◽  
Ternary Alloy ◽  
Phase Stability ◽  
Density Functional Calculations ◽  
Density Functional ◽  
Hybrid Functional ◽  
Hybrid Density Functional

MxZn1−xO ternary alloy formations were explored through the application of the SQS method and hybrid density functional calculations.

Density Functional Calculations of EPR Parameter g Tensors of Some Transition Metal Complexes

2011 ◽  
Vol 2 (2) ◽  
pp. 139-141
Author(s):  
Vinita Prajapati ◽  
◽  
P.L.Verma P.L.Verma ◽  
Dhirendra Prajapati ◽  
B.K.Gupta B.K.Gupta
Keyword(s):  
Transition Metal ◽  
Metal Complexes ◽  
Transition Metal Complexes ◽  
Density Functional Calculations ◽  
Density Functional

scholarly journals On the Effects of Doping on the Catalytic Performance of (La,Sr)CoO3. A DFT Study of CO Oxidation

Catalysts ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 312 ◽  
Author(s):  
Antonella Glisenti ◽  
Andrea Vittadini
Keyword(s):  
Catalytic Activity ◽  
Co Oxidation ◽  
Density Functional Calculations ◽  
Density Functional ◽  
Formation Energy ◽  
Oxygen Vacancies ◽  
Catalytic Performance ◽  
Energy Profiles ◽  
High Concentrations ◽  
3D Impurities

The effects of modifying the composition of LaCoO3 on the catalytic activity are predicted by density functional calculations. Partially replacing La by Sr ions has benefical effects, causing a lowering of the formation energy of O vacancies. In contrast to that, doping at the Co site is less effective, as only 3d impurities heavier than Co are able to stabilize vacancies at high concentrations. The comparison of the energy profiles for CO oxidation of undoped and of Ni-, Cu-m and Zn-doped (La,Sr)CoO3(100) surface shows that Cu is most effective. However, the effects are less spectacular than in the SrTiO3 case, due to the different energetics for the formation of oxygen vacancies in the two hosts.

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