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Search results for: QUANTUM
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Photoresponsive Amide-Based Derivatives of Azobenzene-4,4′-Dicarboxylic Acid—Experimental and Theoretical Studies
PublicationAzobenzene derivatives are one of the most important molecular switches for biological and material science applications. Although these systems represent a well-known group of compounds, there remains a need to identify the factors influencing their photochemical properties in order to design azobenzene-based technologies in a rational way. In this contribution, we describe the synthesis and characterization of two novel amides...
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Experimental and Theoretical Screening for Green Solvents Improving Sulfamethizole Solubility
PublicationSolubility enhancement of poorly soluble active pharmaceutical ingredients is of crucial importance for drug development and processing. Extensive experimental screening is limited due to the vast number of potential solvent combinations. Hence, theoretical models can offer valuable hints for guiding experiments aimed at providing solubility data. In this paper, we explore the possibility of applying quantum-chemistry-derived...
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Review of Recent Advancement on Nature/Bio-inspired Antenna Designs
PublicationThis article presents an extensive examination of antennas rooted in nature and biology, showcasing their remarkable performance across a wide spectrum of frequencies—from microwave to terahertz. The limitations of traditional antenna design have become increasingly evident in the face of burgeoning demands for novel communication technologies. Conventional analytical-equation-based approaches struggle to deliver the combined performance...
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Magnetic anisotropy and structural flexibility in the f ield-induced single ion magnets [Co{(OPPh2) (EPPh2)N}2], E = S, Se, explored by experimental and computational methods
PublicationDuring the last few years, a large number of mononuclear Co(II) complexes of various coordination geometries have been explored as potential single ion magnets (SIMs). In the work presented herein, the Co(II) S = 3/2 tetrahedral [Co{(OPPh2)(EPPh2)N}2], E = S, Se, complexes (abbreviated as CoO2E2), bearing chalcogenated mixed donor-atom imidodiphosphinato ligands, were studied by both experimental and computational techniques. Specifically,...
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Nonconventional 1,8-Diazafluoren-9-One Aggregates for Green Light Enhancement in Hybrid Biocompatible Media
PublicationOrganic aggregates currently play a prominent role, mainly for their unique optoelectronic properties in the aggregated state. Such properties can be related to the aggregates’ structure and the molecular packing mode. In the literature, we have well-established models of H and J aggregates defined based on the molecular exciton model. However, unconventional aggregates, the most unrecognized forms, have been generating interest...
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The ONETEP linear-scaling density functional theory program
PublicationWe present an overview of the ONETEP program for linear-scaling density functional theory (DFT) calculations with large basis set (planewave) accuracy on parallel computers. The DFT energy is computed from the density matrix, which is constructed from spatially localized orbitals we call Non-orthogonal Generalized Wannier Functions (NGWFs), expressed in terms of periodic sinc (psinc) functions. During the calculation, both the...
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Two-body dissociation of isoxazole following double photoionization – an experimental PEPIPICO and theoretical DFT and MP2 study
PublicationThe dissociative double photoionization of isoxazole molecules has been investigated experimentally and theoretically. The experiment has been carried out in the 27.5–36 eV photon energy range using vacuum ultraviolet (VUV) synchrotron radiation excitation combined with ion time-of-flight (TOF) spectrometry and photoelectron–photoion–photoion coincidence (PEPIPICO) technique. Five wellresolved two-body dissociation channels have...
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Chemiluminogenic acridinium salts: A comparison study. Detection of intermediate entities appearing upon light generation
PublicationThe nine derivatives of acridine-9-carboxylic acid (CMADs) capable for chemiluminescence (CL), representing various classes of compounds were isolated in a chemically pure state (assessed by RP-HPLC) and identified using high resolution mass spectrometry (ESI-QTOF) and magnetic resonance (1H NMR) techniques. Among them are aryl acridinium esters, containing certainly selected and located substituents in both aromatic systems, an...
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Mono- and bimetallic (Pt/Cu) titanium(IV) oxide core–shell photocatalysts with UV/Vis light activity and magnetic separability
PublicationTitanium(IV) oxide is one of the most widely investigated photocatalysts. However, separation of nano-sized particulate titania might result in profitless technologies for commercial applications. Additionally, bare titania is almost inactive under the Vis range of solar spectrum due to its wide bandgap. Therefore, the present study aims to prepare novel coreinterlayer- shell TiO2 magnetic photocatalysts modified with metal nanoparticles...
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Density functional theory-based simulations of sum frequency generation spectra involving methyl stretching vibrations: effect of the molecular model on the deduced molecular orientation and comparison with an analytical approach
PublicationThe knowledge of the first hyperpolarizability tensor elements of molecular groups is crucial for a quantitative interpretation of the sum frequency generation (SFG) activity of thin organic films at interfaces. Here, the SFG response of the terminal methyl group of a dodecanethiol (DDT) monolayer has been interpreted on the basis of calculations performed at the density functional theory (DFT) level of approximation. In particular,...
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H2O˙+ and OH+ reactivity versus furan: experimental low energy absolute cross sections for modeling radiation damage
PublicationRadiotherapy is one of the most widespread and efficient strategies to fight malignant tumors. Despite its broad application, the mechanisms of radiation-DNA interaction are still under investigation. Theoretical models to predict the effects of a particular delivered dose are still in their infancy due to the difficulty of simulating a real cell environment, as well as the inclusion of a large variety of secondary processes. This...
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Performance of the AMOEBA Water Model in the Vicinity of QM Solutes: A Diagnosis Using Energy Decomposition Analysis
PublicationThe importance of incorporating solvent polarization effects into the modeling of solvation processes has been well-recognized, and therefore a new generation of hybrid quantum mechanics/molecular mechanics (QM/MM) approaches that accounts for this effect is desirable. We present a fully self-consistent, mutually polarizable QM/MM scheme using the AMOEBA force field, in which the total energy of the system is variationally minimized...
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Rhythm and Colours of the Angles
PublicationABSTRACT The game of space was and still is a crucial aspect of visual arts. The aim of this study is to examine how the arrangement of hues, rhythms and angles of various polygons can create an impression of depth and movement on a flat surface. The so-called Penrose tiling and Ulam's spiral are mathematical models that have been applied for the painting experiment. There is a vast amount of evidence gathered over the ages that...
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Adsorption behavior and corrosion inhibitive characteristics of newly synthesized cyano-benzylidene xanthenes on copper/sodium hydroxide interface: Electrochemical, X-ray photoelectron spectroscopy and theoretical studies
PublicationElegant process for synthesis of 3-(7H-dibenzo[c,h]xanthen-7-yl)benzaldehyde (3), as new starting material to create a set of novel xanthene analogues, 2-(3-(7H-dibenzo[c,h]xanthen-7-yl)benzylidene)malononitrile (4), 3-(3-(7H-dibenzo[c,h]xanthen-7-yl)phenyl)-2-cyanoacrylic acid (5), and Ethyl-3-(3-(7H-dibenzo[c,h]xanthen-7-yl)phenyl)-2-cyanoacrylate (6), was achieved starting with available materials under mild conditions. Various...
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Separability in terms of a single entanglement witness
PublicationThe separability problem is formulated in terms of a characterization of a single entanglement witness. More specifically, we show that any (in general multipartite) state rho is separable if and only if a specially constructed entanglement witness W-rho is weakly optimal, i.e., its expectation value vanishes on at least one product vector. Interestingly, the witness can always be chosen to be decomposable. Our result changes the...
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Nanoparticles preparation using microemulsion systems
PublicationMetallic nanoparticles become of current interests because they exhibit unique properties compared with those of metal atoms or bulk metal due to the quantum size effect and their large surface area, which make them attractive for applications in optics, electronics, catalysis biology and medicine. TiO2 has been used for environmental remediation purposes such as in the purification of water and air and also solar-to chemical energy...