Solid-liquid interfaces are at the heart of many modern-day technologies and provide a challenge to materials simulation methods. A realistic first-principles computational study such systems entails inclusion solvent effects. In this work, we implement an implicit solvation model that has firm theoretical foundation into widely used density-functional code Vienna ab initio Software Package. The follows framework joint density functional theory. We describe framework, our algorithm...

The ab initio computational treatment of electrochemical systems requires an appropriate the solid/liquid interfaces. A fully quantum mechanical interface is computationally demanding due to large number degrees freedom involved. In this work, we develop a efficient model where electrode part described at density-functional theory (DFT) level, and electrolyte represented through implicit solvation based on Poisson-Boltzmann equation. We describe implementation linearized equation into Vienna...

The recent synthesis of single-layer GaS and GaSe opens the question stability for other group-III monochalcogenides (MX, M = Ga In, X S, Se, Te) how dimension reduction affects properties these materials. Using a first-principles design approach, we determine that exhibit low formation energies are suitable photocatalytic water splitting. First, density-functional calculations using van der Waals functional reveal have similar to MoS2, implying ease mechanically extracting from their...

Two-dimensional (2D) materials exhibit a range of extraordinary electronic, optical, and mechanical properties different from their bulk counterparts with potential applications for 2D emerging in energy storage conversion technologies. In this Perspective, we summarize the recent developments field solar water splitting using review computational screening approach to rapidly efficiently discover more that possess suitable splitting. Computational tools based on density-functional theory...

Some of the members family single-layer transition-metal dichalcogenides have recently received a lot attention for their promising electronic properties, with potential applications in devices. In this work, we focus on stability and determine photocatalytic water splitting. Using first-principles design approach, perform systematic theoretical study MX2 (M = Nb, Mo, Ta, W, Ti, V, Zr, Hf, Pt; X S, Se, Te). First, use van der Waals functional to accurately calculate formation energies. The...

Two-dimensional (2D) materials present many unique concepts, including material properties that sometimes differ dramatically from those of their bulk counterparts. One these properties, piezoelectricity, is important for micro- and nanoelectromechanical systems applications. Using symmetry analysis, we determine the independent piezoelectric coefficients four groups predicted synthesized 2D materials. We calculate with density-functional perturbation theory stiffness tensors in-plane...

We present a simple, robust, and highly efficient method for optimizing all parameters of many-body wave functions in quantum Monte Carlo calculations, applicable to continuum systems lattice models. Based on strong zero-variance principle, diagonalization the Hamiltonian matrix space spanned by function its derivatives determines optimal parameters. It systematically reduces fixed-node error, as demonstrated calculation binding energy small but challenging ${\mathrm{C}}_{2}$ molecule...

Computationally characterizing magnetic properies of novel two-dimensional (2D) materials serves as an important first step exploring possible applications. Using density-functional theory, we show that single-layer ${\mathrm{Fe}}_{3}{\mathrm{GeTe}}_{2}$ is a potential 2D material with sufficiently low formation energy to be synthesized by mechanical exfoliation from the bulk phase van der Waals layered structure. In addition, calculated phonon dispersion demonstrating dynamically stable....

We use atomic force microscopy to image grain boundaries and ripples in graphene membranes obtained by chemical vapor deposition. Nanoindentation measurements reveal that out-of-plane effectively soften graphene's in-plane stiffness. Furthermore, significantly decrease the breaking strength of these membranes. Molecular dynamics simulations are especially weakening when subnanometer voids present lattice. Finally, we demonstrate two brought together form with higher resistance breaking.

Single-layer materials open up tremendous opportunities for nanoelectronic devices. Using a first-principles design approach we identify previously unrecognized family of single-layer III-V materials. We determine their energetic and dynamical stability, surprising reconstruction, calculate electronic properties using hybrid density functional the ${G}_{0}{W}_{0}$ method. Finally, find that metal substrates stabilize these as-yet hypothetical Our results provide guidance experimental...

Few-layer graphene is a prototypical layered material, whose properties are determined by the relative orientations and interactions between layers. Exciting electrical optical phenomena have been observed for special case of Bernal-stacked few-layer graphene, but structure–property correlations in which deviates from this structure not well understood. Here, we combine two direct imaging techniques, dark-field transmission electron microscopy (DF-TEM) widefield Raman imaging, to establish...

The rechargeable lithium-sulfur (Li-S) battery is an attractive platform for high-energy, low-cost electrochemical energy storage. Practical Li-S cells are limited by several fundamental issues, including the low conductivity of sulfur and its reduction compounds with Li dissolution long-chain lithium polysulfides (LiPS) into electrolyte. We report on approach that allows high-performance sulfur-carbon cathodes to be designed based tethering polyethylenimine (PEI) polymers bearing large...

The Materials Project crystal structure database has been searched for materials possessing layered motifs in their structures using a topology-scaling algorithm. algorithm identifies and measures the sizes of bonded atomic clusters structure's unit cell, determines scaling with cell size. search yielded 826 stable that are considered as candidates formation two-dimensional monolayers via exfoliation. Density-functional theory was used to calculate exfoliation energy each material 680 emerge...

Density functional calculations determine the structure, stability, and electronic properties of two-dimensional materials in family group-IV monochalcogenides, MX (M = Ge, Sn, Pb; X O, S, Se, Te). Calculations with a van der Waals show that IV-VI compounds are most stable either highly distorted NaCl-type structure or single-layer litharge type tetragonal structure. Their formation energies comparable to MoS2, indicating ease mechanical exfoliation from their layered bulk structures. The...

Surface energies are important for predicting the shapes of nanocrystals and describing faceting roughening surfaces. Copper surfaces particular interest in recent years since they preferred growing graphene using chemical vapor deposition. In this study we calculate surface copper three low-index facets (111), (100), (110) one high-index facet, (210), density-functional theory with both local-density approximation various parametrizations generalized-gradient to exchange-correlation...

We present a first-principles study of the photocatalytic properties single-layer SnS${}_{2}$. First, we calculate formation energy and phonon spectrum, verifying static dynamical stability, respectively. In addition, our calculated solvation suggests that SnS${}_{2}$ is stable in aqueous solution. Next, by solving Bethe-Salpeter equation, obtain an optical band gap 2.75 eV, consistent with measured gap. The resulting exciton binding 0.41 eV Mott-Wannier model. Finally, aligning edges redox...

Density functional calculations for the binding energy of oleic acid-based ligands on Pb-rich {100} and {111} facets PbSe nanocrystals determine surface energies as a function ligand coverage. Oleic acid is expected to bind nanocrystal in form lead oleate. The Wulff construction predicts thermodynamic equilibrium shape nanocrystals. coverage, which can be controlled by changing concentration during synthesis. different results coverages facets, transition from octahedral cubic predicted when...

First-principles calculations are used to compare the binding energies of O, OH, and F on two-dimensional, metal carbide nitride, or MXene, surfaces in order predict dependence thermodynamic stability these compounds their chemical composition. Solvation effects implicitly included reproduce experimental conditions as closely possible. The results indicate that all MXene saturated with oxygen when exposed H2O/HF solutions at low hydrogen potential, μH, Sc-based MXenes can also be fluorinated...

CrSiTe3 has attracted recent interest as a candidate single-layer ferromagnetic semiconductor, but relatively little is known about the bulk properties of this material. Here, we report single-crystal X-ray diffraction, magnetic properties, thermal conductivity, vibrational, and optical spectroscopies compare our findings with complementary electronic structure lattice dynamics principles calculations. The high temperature paramagnetic phase characterized by strong spin-lattice interactions...

van der Waals epitaxial growth of graphene on c-plane (0001) sapphire by CVD without a metal catalyst is presented. The effects CH(4) partial pressure, temperature, and H(2)/CH(4) ratio were investigated conditions optimized. formation monolayer was shown Raman spectroscopy, optical transmission, grazing incidence X-ray diffraction (GIXRD), low voltage transmission electron microscopy (LVTEM). Electrical analysis revealed that room temperature Hall mobility above 2000 cm(2)/V·s achieved, the...

Single-layer transition metal dichalcogenides exhibit a variety of atomic structures and associated exotic electronic magnetic properties. Density-functional calculations using the LDA+$U$ approximation show that single-layer ${\mathrm{VS}}_{2}$ is strongly correlated material, where stability, phonon spectra, moments octahedral ($1T$) trigonal prismatic ($2H$) significantly depend on effective Hubbard $U$ parameter, ${U}_{\mathrm{eff}}$. Comparison with HSE06 hybrid density functional used...

Through a systematic search of all layered bulk compounds combined with density functional calculations employing hybrid exchange-correlation functionals, we predict family three magnetic two-dimensional (2D) materials half-metallic band structures. The 2D materials, FeCl2, FeBr2, and FeI2, are sufficiently stable to be exfoliated from compounds. Fe2+ ions in these high-spin octahedral d6 configuration leading large moment 4 μB. Calculations the anisotropy show an easy-plane for moment. A...

Synthetic two-dimensional polymorphs of boron, or borophene, have attracted attention because their anisotropic metallicity, correlated-electron phenomena, and diverse superlattice structures. Although borophene heterostructures been realized, ordered chemical modification has not yet reported. Here, we synthesize "borophane" by hydrogenating with atomic hydrogen in ultrahigh vacuum. Through atomic-scale imaging, spectroscopy, first-principles calculations, the most prevalent borophane...

Abstract Motivated by the recent observation of superconductivity with T c ~ 80 K in pressurized La 3 Ni 2 O 7 1 , we explore structural and electronic properties A bilayer nickelates ( = La-Lu, Y, Sc) as a function pressure (0–150 GPa) from first principles including Coulomb repulsion term. At 20 GPa, observe an orthorhombic-to-tetragonal transition at variance x-ray diffraction data, which points to so-far unresolved complexities onset superconductivity, e.g., charge doping variations...