Untangling the Raman spectrum of cubic and tetragonal BaZrO3 Permalink
Raman spectroscopy is a widely used experimental technique to study the vibrational properties of solids. Atomic scale simulations can be used to predict suc...
2024
Highly efficient path-integral molecular dynamics simulations with GPUMD using neuroevolution potentials: Case studies on thermal properties of materials Permalink
Path-integral molecular dynamics (PIMD) simulations are crucial for accurately capturing nuclear quantum effects in materials. However, their computational i...
Optical line shapes of color centers in solids from classical autocorrelation functions Permalink
Color centers play key roles in applications, including, e.g., solid state lighting and quantum information technology, for which the coupling between their ...
Machine Learning-Based Interpretation of Optical Properties of Colloidal Gold with Convolutional Neural Networks Permalink
Gold nanoparticles are used in a range of applications, but their properties depend on their shape, size, and polydispersity. A quick, easy, and accurate cha...
Investigating the missing-wedge problem in small-angle X-ray scattering tensor tomography across real and reciprocal space Permalink
Small-angle scattering tensor tomography is a technique for studying anisotropic nanostructures of millimeter-sized samples in a volume-resolved manner. It r...
Controlling Plasmonic Catalysis via Strong Coupling with Electromagnetic Resonators Permalink
Plasmonic excitations decay within femtoseconds, leaving non-thermal (often referred to as “hot”) charge carriers behind that can be injected into molecular ...
Origin of Macroscopic Observables of Strongly Coupled Metal Nanoparticle–Molecule Systems from Microscopic Electronic Properties Permalink
Strongly coupled light–matter systems are becoming a ubiquitous platform for investigating an increasing number of physical phenomena from modifying charge t...
Impact of Organic Spacers and Dimensionality on Templating of Halide Perovskites Permalink
Two-dimensional (2D) halide perovskites (HPs) are promising materials for various optoelectronic applications, yet a comprehensive understanding of their dyn...
Direct, indirect, and self-trapped excitons in Cs2AgBiBr6 Permalink
Cs2AgBiBr6 is a representative halide double perovskite which exhibits promising photovoltaic and light-emitting properties, making it a candidate for next-g...
Construction and sampling of alloy cluster expansions - A tutorial Permalink
Crystalline alloys and related mixed systems make up a large family of materials with high tunability which have been proposed as the solution to a large num...
Tensorial properties via the neuroevolution potential framework: Fast simulation of infrared and Raman spectra Permalink
Infrared and Raman spectroscopy are widely used for the characterization of gases, liquids, and solids, as the spectra contain a wealth of information concer...
Tailoring hot-carrier distributions of plasmonic nanostructures through surface alloying Permalink
Alloyed metal nanoparticles are a promising platform for plasmonically enabled hot-carrier generation, which can be used to drive photochemical reactions. Al...
calorine: A Python package for constructing and sampling neuroevolution potential models Permalink
Molecular dynamics (MD) simulations are a key tool in computational chemistry, physics, and materials science, aiding the understanding of microscopic proces...
Phonon-bottleneck enhanced exciton emission in 2D perovskites Permalink
Layered halide perovskites exhibit remarkable optoelectronic properties and technological promise, driven by strongly bound excitons. The interplay of spin-o...
Machine Learning for Polaritonic Chemistry: Accessing chemical kinetics Permalink
Altering chemical reactivity and material structure in confined optical environments is on the rise, and yet, a conclusive understanding of the microscopic m...
Quantitative predictions of the thermal conductivity in transition metal dichalcogenides: Impact of point defects in MoS2 and WS2 monolayers Permalink
Transition metal dichalcogenides are investigated for various applications at the nanoscale because of their unique combination of properties and dimensional...
Understanding correlations in BaZrO3: Structure and dynamics on the nano-scale Permalink
Barium zirconate BaZrO3 is one of few perovskites that is claimed to retain an average cubic structure down to 0 K at ambient pressure, while being energetic...
GPAW: open Python package for electronic-structure calculations Permalink
We review the GPAW open-source Python package for electronic structure calculations. GPAW is based on the projector-augmented wave method and can solve the s...
2023
Tuning the through-plane lattice thermal conductivity in van-der-Waals structures through rotational (dis)ordering Permalink
It has recently been demonstrated that MoS2 with irregular interlayer rotations can achieve an extreme anisotropy in the lattice thermal conductivity (LTC), ...
Accelerating Plasmonic Hydrogen Sensors for Inert Gas Environments by Transformer-Based Deep Learning Permalink
The ability to rapidly detect hydrogen gas upon occurrence of a leak is critical for the safe large-scale implementation of hydrogen (energy) technologies. H...
General-purpose machine-learned potential for 16 elemental metals and their alloys Permalink
Machine-learned potentials (MLPs) trained against quantum-mechanical reference data have demonstrated remarkable accuracy, surpassing empirical potentials. H...
The Fermi Energy as Common Parameter to Describe Charge Compensation Mechanisms: A Path to Fermi Level Engineering of Oxide Electroceramics Permalink
Chemical substitution, which can be iso- or heterovalent, is the primary strategy to tailor material properties. There are various ways how a material can re...
Revealing the free energy landscape of halide perovskites: Metastability and transition characters in CsPbBr3 and MAPbI3 Permalink
Halide perovskites have emerged as a promising class of materials for photovoltaic applications. A challenge in these applications is how to prevent the crys...
Phase transitions in inorganic halide perovskites from machine-learned potentials Permalink
The atomic scale dynamics of halide perovskites have a direct impact not only on their thermal stability but their optoelectronic properties. Progress in mac...
Limits of the phonon quasi-particle picture at the cubic-to-tetragonal phase transition in halide perovskites Permalink
The soft modes associated with continuous-order phase transitions are associated with strong anharmonicity. This leads to the overdamped limit where the phon...
Small-angle scattering tensor tomography algorithm for robust reconstruction of complex textures Permalink
The development of small-angle scattering tensor tomography has enabled the study of anisotropic nanostructures in a volume-resolved manner. It is of great v...
Quantifying Dynamic Tilting in Halide Perovskites: Chemical Trends and Local Correlations Permalink
Halide perovskites have emerged as one of the most interesting materials for optoelectronic applications due to their favorable properties, such as defect-to...
Electrostatic Boundary Conditions and (Electro)Chemical Interface Stability Permalink
Interface stability is a key factor for stable operation of electronic and electrochemical devices. This contribution introduces an approach for the operando...
2022
The Wulff construction goes low-symmetry Permalink
An apparent quirk of mathematics draws on asymmetry and resolves the issue of how to determine the equilibrium shape of crystals of two-dimensional materials...
The moiré potential in twisted transition metal dichalcogenide bilayers Permalink
Moiré superlattices serve as a playground for emerging phenomena, such as localization of band states, superconductivity, and localization of excitons. These...
Hot-carrier transfer across a nanoparticle-molecule junction: The importance of orbital hybridization and level alignment Permalink
While direct hot-carrier transfer can increase photo-catalytic activity, it is difficult to discern experimentally and competes with several other mechanisms...
High-throughput characterization of transition metal dichalcogenide alloys: Thermodynamic stability and electronic band alignment Permalink
Alloying offers a way to tune many of the properties of the transition metal dichalcogenide (TMD) monolayers. While these systems in many cases have been tho...
GPUMD: A package for constructing accurate machine-learned potentials and performing highly efficient atomistic simulations Permalink
We present our latest advancements of machine-learned potentials (MLPs) based on the neuroevolution potential (NEP) framework introduced in [Fan et al., Phys...
Self-consistent calculations of charge self-trapping energies: A comparative study of polaron formation and migration in PbTiO3 Permalink
This study presents a systematic assessment of the behavior of self-trapped electrons in PbTiO3, which is a prototypical ferroelectric material with a wide r...
Computational Design of Alloy Nanostructures for Optical Sensing of Hydrogen Permalink
Pd nanoalloys show great potential as hysteresis-free, reliable hydrogen sensors. Here, a multi-scale modeling approach is employed to determine optimal cond...
Ultrastrong Coupling of a Single Molecule to a Plasmonic Nanocavity: A First-Principles Study Permalink
Ultrastrong coupling (USC) is a distinct regime of light-matter interaction in which the coupling strength is comparable to the resonance energy of the cavit...
Quantitative predictions of thermodynamic hysteresis: Temperature-dependent character of the phase transition in Pd–H Permalink
The thermodynamics of phase transitions between phases that are size-mismatched but coherent differs from conventional stress-free thermodynamics. Most notab...
2021
Strategic optimization of the electronic transport properties of pseudo-ternary clathrates Permalink
While alloying is a powerful handle for materials engineering, it is an ongoing challenge to navigate the large and complex parameter space of these material...
Storing energy with molecular photoisomers Permalink
Some molecular photoisomers can be isomerized to a metastable high-energy state by exposure to light. These molecules can then be thermally or catalytically ...
Investigating the Chemical Ordering in Quaternary Clathrate Ba8AlxGa16-xGe30 Permalink
Recently there has been an increased interest in quaternary clathrate systems as promising thermoelectric materials. Owing to their increased complexity, the...
Efficient calculation of the lattice thermal conductivity by atomistic simulations with ab-initio accuracy Permalink
High-order force constant expansions can provide accurate representations of the potential energy surface relevant to vibrational motion. They can be efficie...
Extremely anisotropic van der Waals thermal conductors Permalink
The densification of integrated circuits requires thermal management strategies and high thermal conductivity materials. Recent innovations include the devel...
Exciton landscape in van der Waals heterostructures Permalink
Van der Waals heterostructures consisting of vertically stacked transition metal dichalcogenides (TMDs) exhibit a rich landscape of bright and dark intra- an...
First-principles study of order-disorder transitions in pseudo-binary clathrates Permalink
It has been recently demonstrated that the pseudo-ternary Ba8AlxGayGe46-x-y clathrate undergoes an order-disorder transition with increasing temperature that...
Vitrification of octonary perylene mixtures with ultralow fragility Permalink
Strong glass formers with a low fragility are highly sought-after because of the technological importance of vitrification. In the case of organic molecules ...
Hydrogen-driven Surface Segregation in Pd-alloys from Atomic Scale Simulations Permalink
The safe widespread application of hydrogen-based fuels requires sensors that are long-term stable, inexpensive, hydrogen specific and have a short response ...
Order–Disorder Transition in Inorganic Clathrates Controls Electrical Transport Properties Permalink
Inorganic clathrates have been extensively investigated owing to their unique and intriguing atomic structure as well as their potential as thermoelectric ma...
A tale of two phase diagrams: Interplay of ordering and hydrogen uptake in Pd-Au-H Permalink
Due to their ability to reversibly absorb/desorb hydrogen without hysteresis, Pd–Au nanoalloys have been proposed as materials for hydrogen sensing. For sens...
Vibrational signatures for the identification of single-photon emitters in hexagonal boron nitride Permalink
Color centers in h-BN are among the brightest emission centers known yet the origins of these emission centers are not well understood. Here, using first-pri...
Surface Functionalization of 2D MXenes: Trends in Distribution, Composition, and Electronic Properties Permalink
Using a multiscale computational scheme, we study the trends in distribution and composition of the surface functional groups −O, −OH, and −F on two-dimensio...
Photoluminescence line shapes for color centers in silicon carbide from density functional theory calculations Permalink
Silicon carbide with optically and magnetically active point defects offers unique opportunities for quantum technology applications. Since interaction with ...
Modeling of vibrational and configurational degrees of freedom in hexagonal and cubic tungsten carbide at high temperatures Permalink
Transition metal carbide is a class of materials characterized by high hardness, high melting points, and low chemical reactivity. It is widely used in indus...
To every rule there is an exception: A rational extension of Loewenstein’s rule Permalink
Loewenstein’ s rule states that Al–O–Al motifs are energetically unstable and is fundamental to the understanding and design of zeolites. Here, using a combi...
Relating Atomic Energy, Radius and Electronegativity Through Compression Permalink
Trends in atomic properties are well-established tools for guiding the analysis and discovery of materials. Here, we show how compression can reveal a long s...
Luminescence quenching via deep defect states: A recombination pathway via oxygen vacancies in Ce-doped YAG Permalink
Luminescence quenching via non-radiative recombination channels limits the efficiency of optical materials such as phosphors and scintillators and therefore ...
Dynasor - A tool for extracting dynamical structure factors and current correlation functions from molecular dynamics simulations Permalink
Perturbative treatments of the lattice dynamics are widely successful for many crystalline materials, their applicability is, however, limited for strongly a...
Dipolar coupling of nanoparticle-molecule assemblies: An efficient approach for studying strong coupling Permalink
Strong light-matter interactions facilitate not only emerging applications in quantum and non-linear optics but also modifications of materials properties. I...
2020
Small Electron Polarons in CsPbBr3: Competition between Electron Localization and Delocalization Permalink
We study the nature of excess electrons in CsPbBr3 and identify several single and double polaronic states. We emphasize the importance of proper inclusion o...
Non-bonded Radii of the Atoms Under Compression Permalink
We present quantum mechanical estimates for non-bonded, van der Waals-like, radii of 93 atoms in a pressure range from 0 to 300 gigapascal. Trends in radii a...
Tunable Phases of Moiré Excitons in van der Waals Heterostructures Permalink
Stacking monolayers of transition metal dichalcogenides into a heterostructure with a finite twist-angle gives rise to artificial moiré superlattices with a ...
Hot-Carrier Generation in Plasmonic Nanoparticles: The Importance of Atomic Structure Permalink
Metal nanoparticles are attractive for plasmon-enhanced generation of hot carriers, which may be harnessed in photochemical reactions. In this work, we analy...
Efficient construction of linear models in materials modeling and applications to force constant expansions Permalink
Linear models, such as force constant (FC) and cluster expansions, play a key role in physics and materials science. While they can in principle be parametri...
Defects from phonons: Atomic transport by concerted motion in simple crystalline metals Permalink
Point defects play a crucial role in crystalline materials as they do not only impact the thermodynamic properties but are also central to kinetic processes....
A Library of Late Transition Metal Alloy Dielectric Functions for Nanophotonic Applications Permalink
Accurate complex dielectric functions are critical to accelerate the development of rationally designed metal alloy systems for nanophotonic applications, an...
A Computational Assessment of the Efficacy of Halides as Shape-Directing Agents in Nanoparticle Growth Permalink
We report a comprehensive study of aqueous halide adsorption on nanoparticles of gold and palladium that addresses several limitations hampering the use of a...
Local vibrational modes of Si vacancy spin qubits in SiC Permalink
Silicon carbide is a very promising platform for quantum applications because of the extraordinary spin and optical properties of point defects in this techn...
Understanding Interactions Driving the Template-Directed Self-Assembly of Colloidal Nanoparticles at Surfaces Permalink
Controlled deposition of colloidal nanoparticles using self-assembly is a promising technique for, for example, manufacturing of miniaturized electronics, an...
WulffPack: A Python package for Wulff constructions Permalink
WulffPack is a Python package that carries out the Wulff construction and its generalizations using an efficient algorithm based on calculation of the convex...
Optimizing photon upconversion by decoupling excimer formation and triplet triplet annihilation Permalink
Perylene is a promising annihilator candidate for triplet-triplet annihilation photon upconversion, which has been successfully used in solar cells and in ph...
2019
Influence of Phase Separation and Spinodal Decomposition on Microstructure of Mg2Si1–xSnx Alloys Permalink
Mg2Si1–xSnx alloys with nominal values of x [0.03:0.18] were synthesized at 780°C by solid-state reaction from Mg2Si and Mg2Sn and subsequently annealed at e...
Energy level alignment of Cu(In,Ga)(S,Se)2 absorber compounds with In2S3, NaIn5S8, and CuIn5S8 buffer materials Permalink
Motivated by environmental reasons, In2S3 is a promising candidate for a Cd-free buffer layer in Cu(In,Ga)(S,Se)2 (CIGSSe)-based thin film solar cells. For a...
Thermal conductivity in intermetallic clathrates: A first-principles perspective Permalink
Inorganic clathrates such as Ba8GaxGe46−x and Ba8AlxSi46−x commonly exhibit very low thermal conductivities. A quantitative computational description of this...
Vibrationally induced color shift tuning of photoluminescence in Ce3+-doped garnet phosphors Permalink
A critical challenge in the field of phosphor converted white light emitting diodes (pc-WLEDs) pertains to understanding and controlling the variation of emi...
Effect of local chemistry and structure on thermal transport in doped GaAs Permalink
Using a first-principles approach, we analyze the impact of DX centers formed by S, Se, and Te dopant atoms on the thermal conductivity of GaAs. Our results ...
icet - A Python library for constructing and sampling alloy cluster expansions Permalink
Alloy cluster expansions (CEs) provide an accurate and computationally efficient mapping of the potential energy surface of multi-component systems that enab...
Structurally driven asymmetric miscibility in the phase diagram of W–Ti Permalink
Phase diagrams for multi-component systems represent crucial information for understanding and designing materials but are very time consuming to assess expe...
Strong plasmon-molecule coupling at the nanoscale revealed by first-principles modeling Permalink
Strong light-matter interactions in both the single-emitter and collective strong coupling regimes attract significant attention due to emerging quantum and ...
Solvent Effects on the Absorption Profile, Kinetic Stability, and Photoisomerization Process of the Norbornadiene-Quadricyclanes System Permalink
Molecular photoswitches based on the norbornadiene−quadricyclane (NBD-QC) couple can be used to store solar energy and to release the stored energy as heat o...
New insights on the nature of impurity levels in V-doped In2S3: why is it impossible to obtain a metallic intermediate band? Permalink
Generation of metallic intermediate bands (IBs) in a semiconductor material is a key challenge for increasing the efficiency of solar cells. The formation of...
Direct hot-carrier transfer in plasmonic catalysis Permalink
Plasmonic metal nanoparticles can concentrate optical energy and enhance chemical reactions on their surfaces. Plasmons can interact with adsorbate orbitals ...
The hiphive package for the extraction of high-order force constants by machine learning Permalink
The efficient extraction of force constants (FCs) is crucial for the analysis of many thermodynamic materials properties. Approaches based on the systematic ...
Plasmon-Induced Direct Hot-Carrier Transfer at Metal-Acceptor Interfaces Permalink
Plasmon-induced hot-carrier transfer from a metal nanostructure to an acceptor is known to occur via two key mechanisms: (i) indirect transfer, where the hot...
Interlayer exciton dynamics in van der Waals heterostructures Permalink
Exciton binding energies of hundreds of meV and strong light absorption in the optical frequency range make transition metal dichalcogenides (TMDs) promising...
A Record Chromophore Density in High-Entropy Liquids of Two Low-Melting Perylenes: A New Strategy for Liquid Chromophores Permalink
Liquid chromophores constitute a rare but intriguing class of molecules that are in high demand for the design of luminescent inks, liquid semiconductors, an...
Dithiafulvene derivatized donor-acceptor norbornadienes with redshifted absorption Permalink
Photoisomerization of norbornadiene (N) to its metastable isomer quadricyclane (Q) has attracted interest as a strategy for harvesting and storing solar ener...
2018
Understanding Chemical Ordering in Bimetallic Nanoparticles from Atomic Scale Simulations: The Competition between Bulk, Surface and Strain Permalink
Bimetallic nanoparticles are highly relevant for applications in, e.g., catalysis, sensing, and energy harvesting. Their properties are determined by their s...
Balancing Scattering Channels: A Panoscopic Approach toward Zero Temperature Coefficient of Resistance Using High-Entropy Alloys Permalink
Designing alloys with an accurate temperature‐independent electrical response over a wide temperature range, specifically a low temperature coefficient of re...
Impact of strain on the excitonic linewidth in transition metal dichalcogenides Permalink
Monolayer transition metal dichalcogenides (TMDs) are known to be highly sensitive to externally applied tensile or compressive strain. In particular, strain...
Electric-field-controlled reversible order-disorder switching of a metal tip surface Permalink
While it is well established that elevated temperatures can induce surface roughening of metal surfaces, the effect of a high electric field on the atomic st...
Norbornadiene-based photoswitches with exceptional combination of solar spectrum match and long term energy storage Permalink
Norbornadiene-quadricyclane (NBD-QC) photo-switches are candidates for applications in solar thermal energy storage. Functionally they rely on an intramolecu...
Molecular solar thermal energy storage in photoswitch oligomers increases energy densities and storage times Permalink
Molecular photoswitches can be used for solar thermal energy storage by photoisomerization into high-energy, meta-stable isomers; we present a molecular desi...
Inverted valley polarization in optically excited transition metal dichalcogenides Permalink
Large spin–orbit coupling in combination with circular dichroism allows access to spin-polarized and valley-polarized states in a controlled way in transitio...
Understanding the Interactions between Vibrational Modes and Excited State Relaxation in Y3-xCexAl5O12: Design Principles for Phosphors Based on 5d-4f Transitions Permalink
The oxide garnet Y3Al5O12 (YAG), when a few percent of the activator ions Ce3+ substitutes for Y3+, is a luminescent material widely used in phosphor-convert...
Exciton broadening and band renormalization due to Dexter-like intervalley coupling Permalink
A remarkable property of atomically thin transition metal dichalcogenides (TMDs) is the possibility to selectively address single valleys by circularly polar...
A Unifying Perspective on Oxygen Vacancies in Wide Band Gap Oxides Permalink
Wide band gap oxides are versatile materials with numerous applications in research and technology. Many properties of these materials are intimately related...
Liquid Norbornadiene Photoswitches for Solar Energy Storage Permalink
Due to high global energy demands, there is a great need for development of technologies for exploiting and storing solar energy. Closed cycle systems for st...
2017
Mechanism of Re precipitation in irradiated W-Re alloys from kinetic Monte Carlo simulations Permalink
High-temperature, high-dose, neutron irradiation of W results in the formation of Re-rich clusters at concentrations one order of magnitude lower than the th...
Kohn-Sham decomposition in real-time time-dependent density-functional theory: An efficient tool for analyzing plasmonic excitations Permalink
The real-time-propagation formulation of time-dependent density-functional theory (RT-TDDFT) is an efficient method for modeling the optical response of mole...
Understanding chemical ordering in intermetallic clathrates from atomic scale simulations Permalink
Intermetallic clathrates exhibit great variability with respect to elemental composition and distribution. While this provides a lot of flexibility for tunin...
Beyond Magic Numbers: Atomic Scale Equilibrium Nanoparticle Shapes for Any Size Permalink
In the pursuit of complete control over morphology in nanoparticle synthesis, knowledge of the thermodynamic equilibrium shapes is a key ingredient. While ap...
libvdwxc: A library for exchange-correlation functionals in the vdW-DF family Permalink
We present libvdwxc, a general library for evaluating the energy and potential for the family of vdW-DF exchange–correlation functionals. libvdwxc provides a...
Atomicrex - a general purpose tool for the construction of atomic interaction models Permalink
We introduce atomicrex, an open-source code for constructing interatomic potentials as well as more general types of atomic-scale models. Such effective mode...
Loss channels in triplet-triplet annihilation photon upconversion: importance of annihilator singlet and triplet surface shapes Permalink
Triplet-triplet annihilation photon upconversion (TTA-UC) can, through a number of energy transfer processes, efficiently combine two low frequency photons i...
Finite-temperature properties of nonmagnetic transition metals: Comparison of the performance of constraint-based semilocal and nonlocal functionals Permalink
We assess the performance of nonempirical, truly nonlocal, and semilocal functionals with regard to structural and thermal properties of 3d, 4d, and 5d nonma...
2016
Excitons in scintillator materials: Optical properties and electron-energy loss spectra of NaI, LaBr3, BaI2, and SrI2 Permalink
Materials for scintillator radiation detectors need to fulfill a diverse set of requirements such as radiation hardness and highly specific response to incom...
Thermal transport in van der Waals solids from first-principles calculations Permalink
The lattice thermal expansion and conductivity in bulk Mo and W-based transition metal dichalcogenides are investigated by means of density functional and Bo...
Optimization of the Thermoelectric Power Factor: Coupling between Chemical Order and Transport Properties Permalink
Many thermoelectric materials are multicomponent systems that exhibit chemical ordering, which can affect both thermodynamic and transport properties. Here, ...
Polaronic contributions to oxidation and hole conductivity in acceptor-doped BaZrO3 Permalink
Acceptor-doped perovskite oxides like BaZrO3 are showing great potential as materials for renewable energy technologies where hydrogen acts an energy carrier...
Low Molecular Weight Norbornadiene Derivatives for Molecular Solar-Thermal Energy Storage Permalink
Molecular solar-thermal energy storage systems are based on molecular switches that reversibly convert solar energy into chemical energy. Herein, we report t...
Ab initio prediction of fast non-equilibrium transport of nascent polarons in SrI2: a key to high-performance scintillation Permalink
The excellent light yield proportionality of europium-doped strontium iodide (SrI2:Eu) has resulted in state-of-the-art γ-ray detectors with remarkably high-...
The role of interstitial binding in radiation induced segregation in W-Re alloys Permalink
Due to their high strength and advantageous high-temperature properties, tungsten-based alloys are being considered as plasma-facing candidate materials in f...
Optimization of Norbornadiene Compounds for Solar Thermal Storage by First-Principles Calculations Permalink
Molecular photoswitches capable of storing solar energy are interesting candidates for future renewable energy applications. Here, using quantum mechanical c...
Understanding the Phase Diagram of Self-Assembled Monolayers of Alkanethiolates on Gold Permalink
Alkanethiolate monolayers on gold are important both for applications in nanoscience as well as fundamental studies of adsorption and self-assembly at metal ...
A Comparative Ab-Initio Study of Substituted Norbornadiene-Quadricyclane Compounds for Solar Thermal Storage Permalink
Molecular photoswitches that are capable of storing solar energy, so-called molecular solar thermal storage systems, are interesting candidates for future re...
2015
High-entropy alloys as high-temperature thermoelectric materials Permalink
Thermoelectric (TE) generators that efficiently recycle a large portion of waste heat will be an important complementary energy technology in the future. Whi...
Reversible metal-insulator transition of Ar-irradiated LaAlO3/SrTiO3 interfaces Permalink
The conducting state of a quasi-two-dimensional electron gas (q2DEG), formed at the heterointerface between the two wide-bandgap insulators LaAlO3 (LAO) and ...
High-Entropy Mixtures of Pristine Fullerenes for Solution-Processed Transistors and Solar Cells Permalink
The solubility of pristine fullerenes can be enhanced by mixing C60 and C70 due to the associated increase in configurational entropy. This “entropic dissolu...
Variational polaron self-interaction-corrected total-energy functional for charge excitations in insulators Permalink
We conduct a detailed investigation of the polaron self-interaction (pSI) error in standard approximations to the exchange-correlation (XC) functional within...
Microscopic Origin of Thermal Conductivity Reduction in Disordered van der Waals Solids Permalink
Films of layered substances like WSe2 can exhibit a reduction in the out-of-plane thermal conductivity of more than 1 order of magnitude compared to that of ...
Implications of the band gap problem on oxidation and hydration in acceptor-doped barium zirconate Permalink
Charge carrier concentrations in acceptor-doped proton-conducting perovskites are to a large extent determined by the hydration and oxidation of oxygen vacan...
First-principles study of codoping in lanthanum bromide Permalink
Codoping of Ce-doped LaBr3 with Ba, Ca, or Sr improves the energy resolution that can be achieved by radiation detectors based on these materials. Here, we p...
Dopants and dopant-vacancy complexes in tetragonal lead titanate: A systematic first principles study Permalink
A systematic investigation of dopants in tetragonal lead titanate is presented by screening elements from the third period including K, Ca and all 3d transit...
A first-principles investigation of interstitial defects in dilute tungsten alloys Permalink
The thermodynamic properties of intrinsic and extrinsic (Ti, V, Zr, Nb, Hf, Ta, Re) defects in tungsten have been investigated using density functional theor...
2014
Anisotropic growth of gold nanoparticles using cationic gemini surfactants: effects of structure variations in head and tail groups Permalink
A library of gemini surfactants is employed to study surfactant directed anisotropic growth of gold nanoparticles. The surfactants are modified with respect ...
Efficacy of the DFT+U formalism for modeling hole polarons in perovskite oxides Permalink
We investigate the formation of self-trapped holes (STH) in three prototypical perovskites (SrTiO3, BaTiO3, PbTiO3) using a combination of density functional...
Origin of resolution enhancement by co-doping of scintillators: Insight from electronic structure calculations Permalink
It was recently shown that the energy resolution of Ce-doped LaBr3 scintillator radiation detectors can be crucially improved by co-doping with Sr, Ca, or Ba...
Surface potential at a ferroelectric grain due to asymmetric screening of depolarization fields Permalink
Nonlinear screening of electric depolarization fields, generated by a stripe domain structure in a ferroelectric grain of a polycrystalline material, is stud...
Molecular dynamics simulations of shock-induced plasticity in tantalum Permalink
We present Non-Equilibrium Molecular Dynamics (NEMD) simulations of shock wave compression along the [001] direction in monocrystalline Tantalum, including p...
Intrinsic energy band alignment of functional oxides Permalink
The energy band alignment at interfaces between different materials is a key factor, which determines the function of electronic devices. While the energy ba...
Quasiparticle spectra, absorption spectra, and excitonic properties of NaI and SrI2 from many-body perturbation theory Permalink
We investigate the basic quantum-mechanical processes behind the nonproportional response of scintillators to incident radiation responsible for reduced reso...
2013
Energy Band Alignment between Anatase and Rutile TiO2 Permalink
Using photoelectron spectroscopy, the interface formation of anatase and rutile TiO2 with RuO2 and tin-doped indium oxide (ITO) is studied. It is consistentl...
Molecular dynamics simulations of shock-induced deformation twinning of a body-centered-cubic metal Permalink
Despite a number of previous nonequilibrium molecular dynamics (MD) studies into plasticity in face-centered-cubic metals, and phase transitions in body-cent...
Thermodynamic and mechanical properties of copper precipitates in α-iron from atomistic simulations Permalink
Precipitate hardening is commonly used in materials science to control strength by acting on the number density, size distribution, and shape of solute preci...
Low-Temperature Criticality of Martensitic Transformations of Cu Nanoprecipitates in α-Fe Permalink
Nanoprecipitates form during nucleation of multiphase equilibria in phase segregating multicomponent systems. In spite of their ubiquity, their size-dependen...
Formation and switching of defect dipoles in acceptor-doped lead titanate: A kinetic model based on first-principles calculations Permalink
The formation and field-induced switching of defect dipoles in acceptor doped lead titanate is described by a kinetic model representing an extension of the ...
Contributions of point defects, chemical disorder, and thermal vibrations to electronic properties of Cd1-xZnxTe alloys Permalink
We present a first-principles study based on density functional theory of thermodynamic and electronic properties of the most important intrinsic defects in ...
2012
Calculations of excess free energies of precipitates via direct thermodynamic integration across phase boundaries Permalink
We describe a technique for constraining macroscopic fluctuations in thermodynamic variables well-suited for Monte Carlo (MC) simulations of multiphase equil...
Scalable parallel Monte Carlo algorithm for atomistic simulations of precipitation in alloys Permalink
We present an extension of the semi-grand-canonical (SGC) ensemble that we refer to as the variance-constrained semi-grand-canonical (VC-SGC) ensemble. It al...
Electronic structure of LaBr3 from quasiparticle self-consistent GW calculations Permalink
Rare-earth-based scintillators in general and lanthanum bromide (LaBr3) in particular represent a challenging class of materials due to pronounced spin-orbit...
A first-principles study of helium storage in oxides and at oxide-iron interfaces Permalink
Density-functional theory calculations based on conventional as well as hybrid exchange-correlation functionals have been carried out to study the properties...
Potential barrier at the ferroelectric grain boundary due to asymmetric screening of depolarization fields Permalink
Electric depolarization fields generated by a stripe domain structure in ferroelectrics are considered within a semiconductor model. Field screening due to e...
2011
Batteryless Chemical Detection with Semiconductor Nanowires Permalink
A batteryless chemical sensor is developed by Xianying Wang, Yinmin Wang, and co-workers on p. 117. The nanosensor relies on dynamic interactions of molecule...
First-Principles Calculations of the Urbach Tail in the Optical Absorption Spectra of Silica Glass Permalink
We present density-functional theory calculations of the optical absorption spectra of silica glass for temperatures up to 2400 K. The calculated spectra exh...
Calculation of the substitutional fraction of ion-implanted He in an α-Fe target Permalink
Ion-implantation is a useful technique to study irradiation damage in nuclear materials. To study He effects in nuclear fusion conditions, He is co-implanted...
2010
Pressure-induced phase transition in the electronic structure of palladium nitride Permalink
We present a combined theoretical and experimental study of the electronic structure and equation of state (EOS) of crystalline PdN2. The compound forms abov...
Theory-guided growth of aluminum antimonide single crystals with optimal properties for radiation detection Permalink
First-principles calculations are used to study the thermodynamic and electronic properties of a large set of intrinsic and extrinsic defects in AlSb. The re...
Phonon instabilities in uniaxially compressed fcc metals as seen in molecular dynamics simulations Permalink
We show that the generation of stacking faults in perfect face-centered-cubic fcc crystals, uniaxially compressed along 001 , is due to transverse-acoustic p...
Extrinsic point defects in aluminum antimonide Permalink
We investigate thermodynamic and electronic properties of group IV (C, Si, Ge, Sn) and group VI (O, S, Se, Te) impurities as well as P and H in aluminum anti...
Charge carrier scattering by defects in semiconductors Permalink
A first-principles framework for calculating the rates of charge carrier scattering by defects in semiconductors is presented. First a quantitative formalism...
2009
The influence of short range order on the thermodynamics of Fe-Cr alloys Permalink
Using atomistic simulations of Fe-Cr alloys and computational thermodynamics techniques, we study the influence of short range order (SRO) on the location of...
Interatomic potentials for the Be-C-H system Permalink
Analytical bond-order potentials for beryllium, beryllium carbide and beryllium hydride are presented. The reactive nature of the formalism makes the potenti...
Geometry, electronic structure and thermodynamic stability of intrinsic point defects in indium oxide Permalink
Intrinsic point defects in indium oxide, including vacancies, interstitials as well as antisites, are studied by means of first-principles calculations withi...
Efficient implementation of the concentration-dependent embedded atom method for molecular dynamics and Monte-Carlo simulations Permalink
The concentration-dependent embedded atom method (CD-EAM) is a powerful model for atomistic simulation of concentrated alloys with arbitrarily complex mixing...
Composition-dependent interatomic potentials: A systematic approach to modelling multicomponent alloys Permalink
We propose a simple scheme to construct composition-dependent interatomic potentials for multicomponent systems that, when superposed onto the potentials for...
2008
Short-range order and precipitation in Fe-rich Fe-Cr alloys Permalink
Short-range order (SRO) in Fe-rich Fe-Cr alloys is investigated by means of atomistic off-lattice Monte Carlo simulations in the semi-grand-canonical ensembl...
Molecular dynamics simulations of shock compression of nickel: From monocrystals to nanocrystals Permalink
Shock compression of mono- and nanocrystalline (nc) nickel is simulated over a range of pressures (10-80 GPa) and compared with experimental results. Contrib...
Modeling the electrical conductivity in BaTiO3 on the basis of first-principles calculations Permalink
The dependence of the electrical conductivity on the oxygen partial pressure is calculated for the prototypical perovskite BaTiO3 based on data obtained from...
Intrinsic point defects in aluminum antimonide Permalink
Calculations within density functional theory on the basis of the local density approximation are carried out to study the properties of intrinsic point defe...
Defect-dipole formation in copper-doped PbTiO3 ferroelectrics Permalink
The defect structure of hard copper-modified polycrystalline PbTiO3 ferroelectrics is investigated by means of electron paramagnetic resonance and hyperfine ...
Are there stable long-range ordered Fe1-xCrx compounds? Permalink
The heat of formation of Fe-Cr alloys undergoes an anomalous change of sign at small Cr concentrations. This observation raises the question as to whether th...
2007
Thermodynamics of mono- and di-vacancies in barium titanate Permalink
The thermodynamic and kinetic properties of mono- and di-vacancy defects in cubic (para-electric) barium titanate BaTiO3 are studied by means of density-func...
Thermodynamics of L10 ordering in FePt nanoparticles studied by Monte Carlo simulations based on an analytic bond-order potential Permalink
The size dependence of the order-disorder transition in FePt nanoparticles with an L10 structure is investigated by means of Monte Carlo simulations based on...
Molecular dynamics simulations of hydrogen bombardment of tungsten carbide surfaces Permalink
The interaction between energetic hydrogen and tungsten carbide (WC) is of interest both due to the use of hydrogen-containing plasmas in thin-film manufactu...
First principles calculation of point defects and mobility degradation in bulk AlSb for radiation detection application Permalink
The development of high resolution, room temperature semiconductor radiation detectors requires the introduction of materials with increased carrier mobility...
Band structure of indium oxide: Indirect versus direct band gap Permalink
The nature of the band gap of indium oxide is still a matter of debate. Based on optical measurements the presence of an indirect band gap has been suggested...
Association of oxygen vacancies with impurity metal ions in lead titanate Permalink
Thermodynamic, structural, and electronic properties of isolated copper and iron atoms as well as their complexes with oxygen vacancies in tetragonal lead ti...
Analytic bond-order potential for bcc and fcc iron - comparison with established embedded-atom method potentials Permalink
A new analytic bond-order potential for iron is presented that has been fitted to experimental data and results from first-principles calculations. The angul...
2006
First-principles study of migration mechanisms and diffusion of oxygen in zinc oxide Permalink
We have performed density-functional theory calculations in conjunction with the climbing image nudged elastic band method in order to study the self-diffusi...
First-principles study of intrinsic point defects in ZnO: role of band structure, volume relaxation and finite size effects Permalink
Density-functional theory (DFT) calculations of intrinsic point defect properties in zinc oxide were performed in order to remedy the influence of finite siz...
Diffusion of zinc vacancies and interstitials in zinc oxide Permalink
The self-diffusion coefficient of zinc in ZnO is derived as a function of the chemical potential and Fermi level from first-principles calculations. Density ...
Analytic bond-order potential for atomistic simulations of zinc oxide Permalink
An interatomic potential for zinc oxide and its elemental constituents is derived based on an analytical bond-order formalism. The model potential provides a...
2005
Molecular Dynamics Simulations of Gas Phase Condensation of Silicon Carbide Nanoparticles Permalink
Gas phase condensation of silicon and silicon carbide nanoparticles is studied by molecular-dynamics simulations. By using a recently developed bond-order po...
First-principles study of the structure and stability of oxygen defects in zinc oxide Permalink
A comparative study on the structure and stability of oxygen defects in ZnO is presented. By means of first-principles calculations based on local density fu...
Atomistic modeling of shock-induced void collapse in copper Permalink
Nonequilibrium molecular-dynamics (MD) simulations show that shock-induced void collapse in copper occurs by emission of shear loops. These loops carry away ...
Atomistic mechanism of shock-induced void collapse in nanoporous metals Permalink
We have investigated the microstructural changes in ductile porous metals during high pressure-high strain rate loading employing atomistic simulations and e...
Analytical interatomic potential for modeling nonequilibrium processes in the W-C-H system Permalink
A reactive interatomic potential based on an analytical bond-order scheme is developed for the ternary system W-C-H. The model combines Brenner’s hydrocarbon...
Analytical Potential for Atomistic Simulations of Silicon and Silicon Carbide Permalink
We present an analytical bond-order potential for silicon, carbon and silicon carbide that has been optimized by a systematic fitting scheme. The functional ...
2004
The role of thermostats in modeling vapor phase condensation of silicon nanoparticles Permalink
Condensation of silicon nanoclusters from the vapor phase is investigated by means of atomic scale molecular dynamics simulations and discussed with respect ...
Atomistic shock Hugoniot simulation of single-crystal copper Permalink
Planar shock waves in single-crystal copper were simulated using nonequilibrium molecular dynamics with a realistic embedded atom potential. The simulation r...
2003
Modelling of compound semiconductors: Analytical bond-order potential for gallium, nitrogen and gallium nitride Permalink
An analytical bond-order potential for GaN is presented that describes a wide range of structural properties of GaN as well as bonding and structure of the p...