Toward Accurate Two-Photon Absorption Spectrum Simulations: Exploring the Landscape beyond the Generalized Gradient Approximation.

In this Letter, we present a pioneering analysis of the density functional approximations (DFAs) beyond the generalized gradient approximation (GGA) for predicting two-photon absorption (2PA) strengths of a set of push-pull π-conjugated molecules. In more detail, we have employed a variety of meta-generalized gradient approximation (meta-GGA) functionals, including SCAN, MN15, and M06-2X, to assess their accuracy in describing the 2PA properties of a chosen set of 48 organic molecules. Analytic quadratic response theory is employed for these functionals, and their performance is compared against the previously studied DFAs and reference data obtained at the coupled-cluster CC2 level combined with the resolution-of-identity approximation (RI-CC2).

Radiation-Driven Polymerisation of Methacrylic Acid in Aqueous Solution: A Chemical Events Monte Carlo Study.

This study employed a coarse-grained Monte Carlo (MC) simulation to investigate the radiation-induced polymerisation of methacrylic acid (MAA) in an aqueous solution. This method provides an alternative to traditional kinetic models, enabling a detailed examination of the micro-structure and growth patterns of MAA polymers, which are often not captured in other approaches. In this work, we generated multiple clones of a simulation box, each containing a specific chemical composition.

A polarizable coarse-grained model for metal, metal oxide and composite metal/metal oxide nanoparticles: development and implementation.

We present a polarizable coarse-grained model for metal, metal oxide, and composite metal/metal oxide nanoparticles with well-defined crystalline surfaces. The developed model uses a low-resolution polarizable "surface beads" representation of the nanoparticle's geometry and pairwise cross nanoparticle potential consisting of van der Waals and electrostatic interaction terms. The electrostatic interaction term of the cross nanoparticle potential incorporates a crucial physical aspect of electrostatic interaction into the metal and metal oxide systems, such as induced surface charges, making it possible to explore the nanoparticles' behavior in complex environments as well as investigate the interplay between electrostatic and van der Waals interactions in nanoparticle systems.

A polarizable coarse-grained model for metal, metal oxide and composite metal/metal oxide nanoparticles and its applications.

We present a selected set of exemplifying applications of the novel polarizable coarse-grained model [see the first part] to various outstanding problems in the physics and chemistry of nanoparticles: electrostatic potential around silver and gold nanoparticles; spontaneous and external electric field-driven self-organization of gold and silver nanoparticle systems; and physisorption of carbon dioxide on titanium dioxide nanoparticles decorated with a gold catalyst. In the first application, the developed model has shown capabilities of predicting long-range potential with accuracy comparable to the tight-binding density functional theory methods. Furthermore, the electrostatic potential analysis in hot spot regions allowed us to identify twin defect lines in a silver nanostar as a promising candidate for an enhancer in surface-enhanced Raman spectroscopy.

Antibacterial Activity of Silver and Gold Particles Formed on Titania Thin Films.

Metal-based nanoparticles with antimicrobial activity are gaining a lot of attention in recent years due to the increased antibiotics resistance. The development and the pathogenesis of oral diseases are usually associated with the formation of bacteria biofilms on the surfaces; therefore, it is crucial to investigate the materials and their properties that would reduce bacterial attachment and biofilm formation. This work provides a systematic investigation of the physical-chemical properties and the antibacterial activity of TiO thin films decorated by Ag and Au nanoparticles (NP) against and species associated with oral diseases.