Challenges Reconciling Theory and Experiments in the Prediction of Lattice Thermal Conductivity: The Case of Cu-Based Sulvanites.

The exploration of large chemical spaces in search of new thermoelectric materials requires the integration of experiments, theory, simulations, and data science. The development of high-throughput strategies that combine DFT calculations with machine learning has emerged as a powerful approach to discovering new materials. However, experimental validation is crucial to confirm the accuracy of these workflows.

Theoretical Investigation of the Lattice Thermal Conductivities of II-IV-V Pnictide Semiconductors.

Ternary pnictide semiconductors with II-IV-V stoichiometry hold potential as cost-effective thermoelectric materials with suitable electronic transport properties, but their lattice thermal conductivities (κ) are typically too high. Insights into their vibrational properties are therefore crucial to finding strategies to reduce κ and achieve improved thermoelectric performance. We present a theoretical exploration of the lattice thermal conductivities for a set of pnictide semiconductors with ABX composition (A = Zn, Cd; B = Si, Ge, Sn; and X = P, As) using machine-learning-based regression algorithms to extract force constants from a reduced number of density functional theory simulations and then solving the Boltzmann transport equation for phonons.

Design Principles Guided by DFT Calculations and High-Throughput Frameworks for the Discovery of New Diamond-like Chalcogenide Thermoelectric Materials.

Rational design principles are one pathway to discovering new materials. However, technological breakthroughs rarely occur in this way because these design principles are usually based on incremental advances that seldom lead to disruptive applications. The emergence of machine-learning (ML) and high-throughput (HT) techniques has changed the paradigm, opening up new possibilities for efficiently screening large chemical spaces and creating on-the-fly design principles for the discovery of novel materials with desired properties.

High-Throughput Prediction of the Thermal and Electronic Transport Properties of Large Physical and Chemical Spaces Accelerated by Machine Learning: Charting the of Binary Skutterudites.

Thermal and electronic transport properties are the keys to many technological applications of materials. Thermoelectric, TE, materials can be considered a singular case in which not only one but three different transport properties are combined to describe their performance through their TE figure of merit, . Despite the availability of high-throughput experimental techniques, synthesizing, characterizing, and measuring the properties of samples with numerous variables affecting are not a cost- or time-efficient approach to lead this strategy.

σ-Hole intermolecular interactions between carbon oxides and dihalogens: Ab-initio investigations.

Recently, halogen bonding (XB) has received increased attention as a new type of non-covalent interaction widely present in nature. In this work, quantum chemical calculations at DFT level have been carried out to investigate halogen bonding interactions between CO (n = 1 or 2) and dihalogen molecules XY (X = F, Cl, Br, I and Y = Cl, Br, I). Highly accurate all-electron data, estimated by CCSD(T) calculations, were used to benchmark the different levels of computational methods with the objective of finding the best accuracy/computational cost.

Plasma rich in growth factors versus Mitomycin C in photorefractive keratectomy.

To evaluate the efficacy and safety of plasma rich in growth factors (PRGF) in photorefractive keratectomy (PRK) versus Mitomycin C (MMC).This is a comparative, longitudinal and retrospective case-control study (MMC vs PRGF), in patients with a spherical correction from -0.25 to -8.

Periprocedural Direct Oral Anticoagulant Management: The RA-ACOD Prospective, Multicenter Real-World Registry.

 There is scarce real-world experience regarding direct oral anticoagulants (DOACs) perioperative management. No study before has linked bridging therapy or DOAC-free time (pre-plus postoperative time without DOAC) with outcome. The aim of this study was to investigate real-world management and outcomes.

Understanding the Photocatalytic Properties of Pt/CeO /TiO : Structural Effects on Electronic and Optical Properties.

Ceria-titania interfaces play a crucial role in different chemical processes but are especially promising for the photocatalytic splitting of water using light in the visible wavelength region when Pt is added to the system. However, the complexity of this hierarchical structure hampers the study of the origin of its outstanding properties. In this article, the structural, electronic and optoelectronic properties of CeO /TiO systems containing 1D, 2D, and 3D particles of ceria are analyzed by means of density functional calculations.

Effects of the capping ligands, linkers and oxide surface on the electron injection mechanism of copper sulfide quantum dot-sensitized solar cells.

Quantum dot-sensitized solar cells, QDSCs, are a clean and effective alternative to fossil fuels to reduce CO emissions. However, the different components that constitute the QDSCs and the difficulty of isolating experimentally their effects on the performance of the whole system slow down the development of more efficient devices. In this work, DFT calculations are combined with a bottom-up approach to differentiate the effect of each component on the electronic structure and absorption spectra.

Graphenes as Efficient Metal-Free Fenton Catalysts.

Reduced graphene oxide exhibits high activity as Fenton catalyst with HO(.) radical generation efficiency over 82 % and turnover numbers of 4540 and 15023 for phenol degradation and H2 O2 consumption, respectively. These values compare favorably with those achieved with transition metals, showing the potential of carbocatalysts for the Fenton reaction.

Effect of capping ligands and TiO2 supporting on the optical properties of a (CdSe)13 cluster.

The influence of different aliphatic and aromatic ligand molecules on the electronic properties of CdSe quantum dots (QDs) has been examined by employing density functional theory (DFT). Optical spectra were simulated with the real-time time-dependent DFT (RT-TDDFT) methodology. The assignment of the first absorption peak features that occur in these spectra was done by taking into account the composition of the frontier molecular orbitals (MOs) of the different systems.

Effect of dispersion correction on the Au(1 1 1)-H2O interface: a first-principles study.

A theoretical study of the H(2)O-Au(1 1 1) interface based on first principles density functional theory (DFT) calculations with and without inclusion of dispersion correction is reported. Three different computational approaches are considered. First, the standard generalized gradient approximation (GGA) functional PBE is employed.

Molecular modification of coumarin dyes for more efficient dye sensitized solar cells.

In this work, new coumarin based dyes for dye sensitized solar cells (DSSC) have been designed by introducing several substituent groups in different positions of the NKX-2311 structure. Two types of substitutions have been considered: the introduction of three electron-donating groups (-OH, -NH(2), and -OCH(3)) and two different substituents with steric effect: -CH(2)-CH(2)-CH(2)- and -CH(2)-HC=CH-. The electronic absorption spectra (position and width of the first band and absorption threshold) and the position of the LUMO level related to the conduction band have been used as theoretical criteria to evaluate the efficiency of the new dyes.

Communication: improving the density functional theory+U description of CeO2 by including the contribution of the O 2p electrons.

Density functional theory (DFT) based approaches within the local-density approximation or generalized gradient approximation frameworks fail to predict the correct electron localization in strongly correlated systems due to the lack of cancellation of the Coulomb self-interaction. This problem might be circumvented either by using hybrid functionals or by introducing a Hubbard-like term to account for the on site interactions. This latter DFT+U approach is less expensive and therefore more practical for extensive calculations in solid-state computational simulations.

Thiodiacetate-manganese chemistry with N ligands: unique control of the supramolecular arrangement over the metal coordination mode.

Compounds based on the Mn-tda unit (tda=S(CH(2)COO)(2)(-2) ) and N co-ligands have been analyzed in terms of structural, spectroscopic, magnetic properties and DFT calculations. The precursors [Mn(tda)(H(2)O)](n) (1) and [Mn(tda)(H(2)O)(3)]·H(2)O (2) have been characterized by powder and X-ray diffraction, respectively. Their derivatives with bipyridyl-type ligands have formulas [Mn(tda)(bipy)](n) (3), [{Mn(N-N)}(2)(μ-H(2)O)(μ-tda)(2)](n) (N-N=4,4'-Me(2)bipy (4), 5,5'-Me(2)bipy, (5)) and [Mn(tda){(MeO)(2)bipy}·2H(2)O](n) (6).

Nitrogen/gold codoping of the TiO2(101) anatase surface. A theoretical study based on DFT calculations.

The interaction between implanted nitrogen atoms, adsorbed gold atoms, and oxygen vacancies at the anatase TiO(2)(101) surface is investigated by means of periodic density functional theory calculations. Substitutional and interstitial configurations for the N-doping have been considered, as well as several adsorption sites for Au adatoms and different types of vacancies. Our total energy calculations suggest that a synergetic effect takes place between the nitrogen doping on one hand and the adsorption of gold and vacancy formation on the other hand.

CO oxidation on inverse CeO(x)/Cu(111) catalysts: high catalytic activity and ceria-promoted dissociation of O2.

A Cu(111) surface displays a low activity for the oxidation of carbon monoxide (2CO + O(2) → 2CO(2)). Depending on the temperature, background pressure of O(2), and the exposure time, one can get chemisorbed O on Cu(111) or a layer of Cu(2)O that may be deficient in oxygen. The addition of ceria nanoparticles (NPs) to Cu(111) substantially enhances interactions with the O(2) molecule and facilitates the oxidation of the copper substrate.

Comparative Study on the Performance of Hybrid DFT Functionals in Highly Correlated Oxides: The Case of CeO2 and Ce2O3.

The outstanding catalytic properties of cerium oxides rely on the easy Ce(3+) ↔ Ce(4+) redox conversion, which however constitutes a challenge in density functional based theoretical chemistry due to the strongly correlated nature of the 4f electrons present in the reduced materials. In this work, we report an analysis of the performance of five exchange-correlation functionals (HH, HHLYP, PBE0, B3LYP, and B1-WC) implemented in the CRYSTAL06 code to describe three properties of ceria: crystal structure, band gaps, and reaction energies of the CeO2 → Ce2O3 process. All five functionals give values for cell parameters that are in fairly good agreement with experiment, although the PBE0 hybrid functional is found to be the most accurate.

Real-Time TD-DFT Simulations in Dye Sensitized Solar Cells: The Electronic Absorption Spectrum of Alizarin Supported on TiO2 Nanoclusters.

The structural and electronic properties of the alizarin dye supported on TiO2 nanoclusters have been examined by means of time-dependent density-functional (TD-DFT) calculations performed in the time-domain framework. The calculated electronic absorption spectrum of free alizarin shows a first band centered at 2.67 eV that upon adsorption features a red shift by 0.

A theoretical insight into the catalytic effect of a mixed-metal oxide at the nanometer level: the case of the highly active metal/CeOx/TiO2(110) catalysts.

The structural and electronic properties of CeO(x) species supported on the rutile TiO(2)(110) surface have been examined by means of periodic density-functional calculations that use a generalized gradient approximation functional including a Hubbard-like type correction. Deposition of Ce atoms leads in a first step to Ce(3+) ions bound to the surface through bridge and in-plane oxygen atoms, the released electrons occupying the Ti 3d empty orbitals. Further addition of Ce and molecular oxygen gives place to Ce(2)O(3) dimers diagonally arranged on the surface, in agreement with the spots observed in the scanning tunnel microscope images.

On the difficulties of present theoretical models to predict the oxidation state of atomic Au adsorbed on regular sites of CeO2(111).

The electronic structure and oxidation state of atomic Au adsorbed on a perfect CeO(2)(111) surface have been investigated in detail by means of periodic density functional theory-based calculations, using the LDA+U and GGA+U potentials for a broad range of U values, complemented with calculations employing the HSE06 hybrid functional. In addition, the effects of the lattice parameter a(0) and of the starting point for the geometry optimization have also been analyzed. From the present results we suggest that the oxidation state of single Au atoms on CeO(2)(111) predicted by LDA+U, GGA+U, and HSE06 density functional calculations is not conclusive and that the final picture strongly depends on the method chosen and on the construction of the surface model.

Electronic charge transfer between ceria surfaces and gold adatoms: a GGA+U investigation.

We use density functional theory calculations with Hubbard corrections (DFT+U) to investigate electronic aspects of the interaction between ceria surfaces and gold atoms. Our results show that Au adatoms at the (111) surface of ceria can adopt Au(0), Au(+) or Au(-) electronic configurations depending on the adsorption site. The strongest adsorption sites are on top of the surface oxygen and in a bridge position between two surface oxygen atoms, and in both cases charge transfer from the gold atom to one of the Ce cations at the surface is involved.