We introduce density functional theory and review recent progress in its application to transition metal chemistry. Topics covered include local, meta, hybrid, hybrid meta, and range-separated functionals, band theory, software, validation tests, and applications to spin states, magnetic exchange coupling, spectra, structure, reactivity, and catalysis, including molecules, clusters, nanoparticles, surfaces, and solids.

Density functional theory for transition metals and transition metal chemistry

Gibbs2: A new version of the quasiharmonic model code. II. Models for solid-state thermodynamics, features and implementation ☆ ☆☆

In the search for new functional materials, quantum mechanics is an exciting starting point. The fundamental laws that govern the behaviour of electrons have the possibility, at the other end of the scale, to predict the performance of a material for a targeted application. In some cases, this is achievable using density functional theory (DFT). In this Review, we highlight DFT studies predicting energy-related materials that were subsequently confirmed experimentally. The attributes and limitations of DFT for the computational design of materials for lithium-ion batteries, hydrogen production and storage materials, superconductors, photovoltaics and thermoelectric materials are discussed. In the future, we expect that the accuracy of DFT-based methods will continue to improve and that growth in computing power will enable millions of materials to be virtually screened for specific applications. Thus, these examples represent a first glimpse of what may become a routine and integral step in materials discovery. Density functional theory has become an indispensable tool in the design of new materials. This Review details the principles of computational materials design, highlighting examples of the successful prediction and subsequent experimental verification of materials for energy harvesting, conversion and storage.

/pdf/computational-predictions-of-energy-materials-using-density-2nzdli7e85.pdf

Computational predictions of energy materials using density functional theory

Material properties emerge from phenomena on scales ranging from Angstroms to millimeters, and only a multiscale treatment can provide a complete understanding. Materials researchers must therefore understand fundamental concepts and techniques from different fields, and these are presented in a comprehensive and integrated fashion for the first time in this book. Incorporating continuum mechanics, quantum mechanics, statistical mechanics, atomistic simulations and multiscale techniques, the book explains many of the key theoretical ideas behind multiscale modeling. Classical topics are blended with new techniques to demonstrate the connections between different fields and highlight current research trends. Example applications drawn from modern research on the thermo-mechanical properties of crystalline solids are used as a unifying focus throughout the text. Together with its companion book, Continuum Mechanics and Thermodynamics (Cambridge University Press, 2011), this work presents the complete fundamentals of materials modeling for graduate students and researchers in physics, materials science, chemistry and engineering.

Modeling Materials: Continuum, Atomistic and Multiscale Techniques

Chemists and material scientists have often focused on the properties of previously reported compounds, but neglect numerous unreported but chemically plausible compounds that could have interesting properties. For example, the 18-valence electron ABX family of compounds features examples of topological insulators, thermoelectrics and piezoelectrics, but only 83 out of 483 of these possible compounds have been made. Using first-principles thermodynamics we examined the theoretical stability of the 400 unreported members and predict that 54 should be stable. Of those previously unreported 'missing' materials now predicted to be stable, 15 were grown in this study; X-ray studies agreed with the predicted crystal structure in all 15 cases. Among the predicted and characterized properties of the missing compounds are potential transparent conductors, thermoelectric materials and topological semimetals. This integrated process-prediction of functionality in unreported compounds followed by laboratory synthesis and characterization-could be a route to the systematic discovery of hitherto missing, realizable functional materials.

Prediction and accelerated laboratory discovery of previously unknown 18-electron ABX compounds

This research has been motivated by geophysics and materials physics. The objective of this research has been to advance materials theory and computations for high pressure and high temperature applications to the point that it can make a difference in our understanding of the Earth. Understanding of the mineralogy, composition, and thermal structure of the Earth evolves by close interaction of three fields: seismology, geodynamics, and mineral physics. Earth’s structure is imaged by seismology, which obtains body wave velocities and density throughout the Earth’s interior (Fig. 1⇓). Interpretation of this data relies on knowledge of aggregate properties of Earth forming materials either measured in laboratory or calculated, in many cases by both. However, the conditions of the Earth’s interior, especially at the core, may be challenging for important experiments, and materials computations have emerged to contribute decisively to this field. Earth’s evolution is simulated by geodynamics, but these simulations need as input information about rheological and thermodynamic properties of minerals, including phase transformation properties such as Clapeyron slopes. Our research has concentrated on the phases of the Earth’s mantle, particularly the deep mantle whose conditions are more challenging for experiments. The mantle accounts for ~83% of the Earth’s volume. In this article we will review the essential first-principles approach used to investigate solids at high temperatures and pressures, summarize their performance for mantle minerals (Fig. 2⇓), and point to critical results that have stirred us in the current research path. The success is remarkable, but some limitations point the way to future developments in this field.



 Figure 1. 
(a) Velocities and density profiles (Kennett et al. 1995), (b) Earth’s cross section, and (c) composition and mineralogy of Earth’s layers.





 Figure 2. 
Phases proportions versus depth and or pressure. Ol = (Mg,Fe)2SiO4 olivine, also known as α-phase; β = (Mg,Fe) …

Thermodynamic Properties and Phase Relations in Mantle Minerals Investigated by First Principles Quasiharmonic Theory

Materials that are both electrically conducting and transparent to light are vital for optoelectronic devices, but are rare. Here, the authors perform a quantum mechanical search for such materials and identify the compound TaIrGe as an unexpected possibility, which they then synthesize.

/pdf/design-and-discovery-of-a-novel-half-heusler-transparent-3xa90aqi1g.pdf

Design and discovery of a novel half-Heusler transparent hole conductor made of all-metallic heavy elements

Spin transition in (Mg,Fe)SiO3 perovskite under pressure

[1] We have investigated the dissociation of iron free ringwoodite, Mg2SiO4γ-spinel, into MgO periclase and MgSiO3 perovskite using quasi-harmonic free energy computations within the local density approximation (LDA) and generalized gradient approximation (GGA). The transition pressure, Ptr, obtained from GGA is higher and in much better agreement with experimental measurements than its LDA counterpart. This can be rationalized by close inspection of GGA and LDA functional forms. The Clapeyron slope obtained from this calculation is −2.9 − −2.6 MPa/K. Surprisingly, we find a small decrease in bulk sound velocity across this transition. Our results are consistent with 64 ± 12% ringwoodite volume fraction at the bottom of the transition zone.

https://agupubs.onlinelibrary.wiley.com/doi/pdf/10.1029/2007GL029462

Yonggang G. Yu

Papers

Thermodynamic Properties and Phase Relations in Mantle Minerals Investigated by First Principles Quasiharmonic Theory

Design and discovery of a novel half-Heusler transparent hole conductor made of all-metallic heavy elements

Spin transition in (Mg,Fe)SiO3 perovskite under pressure

First principles investigation of the postspinel transition in Mg2SiO4

Spin crossover of iron in aluminous MgSiO3 perovskite and post-perovskite