Adiabatic connection interaction strength interpolation method made accurate for the uniform electron gas.

The adiabatic connection interaction strength interpolation (ISI)-like method provides a high-level expression for the correlation energy, being, in principle, exact not only in the weak-interaction limit, where it recovers the second-order Görling-Levy perturbation term, but also in the strong-interaction limit that is described by the strictly correlated electron approach. In this work, we construct a genISI functional made accurate for the uniform electron gas, a solid-state physics paradigm that is a very difficult test for ISI-like correlation functionals. We assess the genISI functional for various jellium spheres with the number of electrons Z ≤ 912 and for the non-relativistic noble atoms with Z ≤ 290.

Semilocal Meta-GGA Exchange-Correlation Approximation from Adiabatic Connection Formalism: Extent and Limitations.

The incorporation of a strong-interaction regime within the approximate semilocal exchange-correlation functionals still remains a very challenging task for density functional theory. One of the promising attempts in this direction is the recently proposed adiabatic connection semilocal correlation (ACSC) approach [Constantin, L. A.

Density functional applications of jellium with a local gap model correlation energy functional.

We develop a realistic density functional approximation for the local gap, which is based on a semilocal indicator that shows good screening properties. The local band model has remarkable density scaling behaviors and works properly for the helium isoelectronic series for the atoms of the Periodic Table, as well as for the non-relativistic noble atom series (up to 2022 e-). Due to these desirable properties, we implement the local gap model in the jellium-with-gap correlation energy, developing the local-density-approximation-with-gap correlation functional (named LDAg) that correctly gives correlation energies of atoms comparable with the LDA ones but shows an improvement for ionization potential of atoms and molecules.

New Chelate Resins Prepared with Direct Red 23 for Cd, Ni, Cu and Pb Removal.

In this paper, two chelate resins prepared by a simple procedure were used for the removal of Cd2+, Ni2+, Cu2+, and Pb2+ (M2+) from aqueous solutions. Amberlite IRA 402 strongly basic anion exchange resin in Cl− form (IRA 402 (Cl−) together with Amberlite XAD7HP acrylic ester co-polymer (XAD7HP) were functionalized with chelating agent Direct red 23 (DR 23). The chelate resins (IRA 402-DR 23 and XAD7HP-DR 23) were obtained in batch mode.

Efficient and improved prediction of the band offsets at semiconductor heterojunctions from meta-GGA density functionals: A benchmark study.

Accurate theoretical prediction of the band offsets at interfaces of semiconductor heterostructures can often be quite challenging. Although density functional theory has been reasonably successful to carry out such calculations, efficient, accurate semilocal functionals are desirable to reduce the computational cost. In general, the semilocal functionals based on the generalized gradient approximation (GGA) significantly underestimate the bulk bandgaps.

Solid-state performance of a meta-GGA screened hybrid density functional constructed from Pauli kinetic enhancement factor dependent semilocal exchange hole.

The semilocal form of an exchange hole is highly useful in developing non-local range-separated hybrid density functionals for finite and extended systems. The way to construct the conventional exact exchange hole model is based on either the Taylor series expansion or the reverse engineering technique from the corresponding exchange energy functional. Although the latter technique is quite popular in the context of generalized gradient approximation (GGA) functionals, the same for the meta-GGA functionals is not so much explored.

Degradation of Carbamazepine from Aqueous Solutions via TiO-Assisted Photo Catalyze.

Photocatalytic degradation of carbamazepine (CBZ) from spiked aqueous solutions, via a UV/TiO system, was investigated, and the optimum photocatalyst type (P25 Degussa) and dose (500 mg/L), as well as irradiation time (45 min), were established. The degradation process kinetics was studied, and a degradation rate constant of 3.14 × 10 M min was calculated for CBZ, using the Langmuir-Hinshelwood equation.

Benchmark test of a dispersion corrected revised Tao-Mo semilocal functional for thermochemistry, kinetics, and noncovalent interactions of molecules and solids.

In the density functional theory, dispersion corrected semilocal approximations are often used to benchmark weekly interacting finite and extended systems. Here, the focus is on providing a broad overview of the performance of D3 dispersion corrected revised Tao-Mo (revTM) semilocal functionals [A. Patra et al.

Insights from the density functional performance of water and water-solid interactions: SCAN in relation to other meta-GGAs.

Accurate prediction of water properties in its gas and condensed phases, including the interaction of water with surfaces, is of prime importance for many scientific disciplines. However, accurate simulation of all water properties together within semilocal approximations of the density functional theory possesses great challenges. The Strongly Constrained and Appropriately Normed semilocal density functional, which satisfies 17 known exact constraints and includes the intermediate range van der Waals interaction, performs quite well for different properties of water including the correct energy ordering of isomers.

Generalizing Double-Hybrid Density Functionals: Impact of Higher-Order Perturbation Terms.

Connections between the Görling-Levy (GL) perturbation theory and the parameters of double-hybrid (DH) density functional are established via adiabatic connection formalism. Moreover, we present a more general DH density functional theory, where the higher-order perturbation terms beyond the second-order GL2 one, such as GL3 and GL4, also contribute. It is shown that a class of DH functionals including previously proposed ones can be formed using the present construction.

Efficient yet accurate dispersion-corrected semilocal exchange-correlation functionals for non-covalent interactions.

The meta-generalized-gradient approximation (meta-GGA) of the exchange-correlation energy functional can provide appealing performance for the wide range of quantum chemistry and solid-state properties. So far, several meta-GGAs are proposed by fitting to the test sets or/and satisfying as many as known exact constraints. Although the density overlap is treated by meta-GGA functionals efficiently, for non-covalent interactions, a long-range dispersion correction is essential.

Modified Interaction-Strength Interpolation Method as an Important Step toward Self-Consistent Calculations.

The modified point charge plus continuum (mPC) model [Constantin, L. A.; 2019, 99, 085117] solves the important failures of the original counterpart, namely, the divergences when the reduced gradient of the density is large, such as in the tail of the density and in quasi-dimensional density regimes.

Unveiling the Physics Behind Hybrid Functionals.

We show that accurate exchange-correlation hybrid functionals give very physically optimized effective-correlation potentials, capable of correctly describing the quantum oscillations of atoms and molecules. Based on this analysis and on understanding the error cancellation between semilocal exchange and correlation functionals, we propose a very simple, semilocal correlation potential model compatible with the exact exchange of density functional theory, which performs remarkably well for charge densities and orbital energies.

Improved transition metal surface energies from a generalized gradient approximation developed for quasi two-dimensional systems.

Nonuniform density scaling in the quasi-two-dimensional (quasi-2D) regime is an important and challenging aspect of the density functional theory. Semilocal exchange-correlation energy functionals, developed by solving the dimensional crossover criterion in the quasi-2D regime, have great theoretical and practical importance. However, the only semilocal generalized gradient approximation (GGA) that has been designed to satisfy this criterion is the Q2D-GGA [L.

Screened range-separated hybrid by balancing the compact and slowly varying density regimes: Satisfaction of local density linear response.

Due to their quantitative accuracy and ability to solve several difficulties, screened range-separated hybrid exchange-correlation functionals are now a standard approach for ab initio simulation of condensed matter systems. However, the screened range-separated hybrid functionals proposed so far are biased either toward compact or slowly varying densities. In this paper, we propose a screened range-separated hybrid functional, named HSEint, which can well describe these density regimes, achieving good accuracy for both molecular and solid-state systems.

Added value recyclability of glass fiber waste as photo-oxidation catalyst for toxic cytostatic micropollutants.

There is an increased interest in recycling valuable waste materials for usage in procedures with high added values. Silica microparticles are involved in the processes of catalysis, separation, immobilization of complexants, biologically active compounds, and different nanospecies, responding to restrictive requirements for selectivity of various chemical and biochemical processes. This paper presents the surface modification of accessible and dimensionally controlled recycled silica microfiber with titanium dioxide.

Accurate Water Properties from an Efficient ab Initio Method.

Accurate prediction of the water properties from a low-cost ab initio method is still a foremost problem for chemists and physicists. Although density functional approaches starting from semilocal to hybrid exchange-correlation functionals are tested, they are not efficiently performing for all the properties together, especially considering energies, conformal ranking, structures, and dynamics of water. Also, the inclusion of the long-range van der Waals interaction does not improve the ordering stability of isomers.

Performance of Semilocal Kinetic Energy Functionals for Orbital-Free Density Functional Theory.

We assess several generalized gradient approximations (GGAs) and Laplacian-level meta-GGAs (LL-MGGA) kinetic energy (KE) functionals for orbital-free density functional theory calculations of bulk metals and semiconductors, considering equilibrium distances, bulk moduli, total and kinetic energies, and the electron densities. We also considered the effects of the pseudopotentials, the vacancy formation energies, and the bond lengths of molecular dimers. We found that LL-MGGA KE functionals are distinctively superior to GGA functionals, showing the importance of the Laplacian of the density in the functional construction.

Modified Fourth-Order Kinetic Energy Gradient Expansion with Hartree Potential-Dependent Coefficients.

Using the semiclassical neutral atom theory, we developed a modified fourth-order kinetic energy (KE) gradient expansion (GE4m) that keeps unchanged all the linear-response terms of the uniform electron gas and gives a significant improvement with respect to the known semilocal functionals for both large atoms and jellium surfaces. On the other hand, GE4m is not accurate for light atoms; thus, we modified the GE4m coefficients making them dependent on a novel ingredient, the reduced Hartree potential, recently introduced in the Journal of Chemical Physics 2016, 145, 084110, in the context of exchange functionals. The resulting KE gradient expansion functional, named uGE4m, belongs to the novel class of u-meta-generalized-gradient-approximations (uMGGA) whose members depend on the conventional ingredients (i.

Laplacian-dependent models of the kinetic energy density: Applications in subsystem density functional theory with meta-generalized gradient approximation functionals.

The development of semilocal models for the kinetic energy density (KED) is an important topic in density functional theory (DFT). This is especially true for subsystem DFT, where these models are necessary to construct the required non-additive embedding contributions. In particular, these models can also be efficiently employed to replace the exact KED in meta-Generalized Gradient Approximation (meta-GGA) exchange-correlation functionals allowing to extend the subsystem DFT applicability to the meta-GGA level of theory.

Hartree potential dependent exchange functional.

We introduce a novel non-local ingredient for the construction of exchange density functionals: the reduced Hartree parameter, which is invariant under the uniform scaling of the density and represents the exact exchange enhancement factor for one- and two-electron systems. The reduced Hartree parameter is used together with the conventional meta-generalized gradient approximation (meta-GGA) semilocal ingredients (i.e.

Global hybrids from the semiclassical atom theory satisfying the local density linear response.

We propose global hybrid approximations of the exchange-correlation (XC) energy functional which reproduce well the modified fourth-order gradient expansion of the exchange energy in the semiclassical limit of many-electron neutral atoms and recover the full local density approximation (LDA) linear response. These XC functionals represent the hybrid versions of the APBE functional [Phys. Rev.