Article
Chemistry, Physical
Pierre Beaujean, Benoit Champagne, Stefan Grimme, Marc de Wergifosse
Summary: A new quantum mechanics methodology is proposed to compute the second-harmonic generation (SHG) of large systems, utilizing recent implementations for geometry optimization and evaluation of response functions, along with a new configuration selection scheme to reduce computational costs. The methodology was successfully tested on evaluating the SHG of proteins iLOV and bacteriorhodopsin (bR).
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Optics
Tikaram Neupane, Hua Wang, William W. Yu, Bagher Tabibi, Felix Jaetae Seo
Summary: The study characterized the averaged second-order hyperpolarizability of pervoskite quantum dots using intensity-dependent spatial self-phase modulation (SSPM), revealing the nonlinear refraction coefficients of the QDs and the all-optical switching characteristics. The input intensity of optical switching was estimated to be around 1.05 MW/m(2).
OPTICS AND LASER TECHNOLOGY
(2021)
Article
Spectroscopy
Omer Tamer, Merve Simsek, Davut Avci, Yusuf Atalay
Summary: This study evaluated the hyperpolarizability parameters of seventeen flavonol derivatives and characterized their spectroscopic properties and quantum chemical parameters. The results suggest that flavonol derivatives with rational substitution may have potential applications in nonlinear optics.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2022)
Article
Chemistry, Multidisciplinary
Ria Sinha Roy, Avik Ghosh, Tamalika Ash, Soumadip Banerjee, Abhijit K. Das
Summary: The effects of complexant number on the static and dynamic second hyperpolarizability of diffuse electron systems comprising aziridine and alkaline earth metal dopant are explored theoretically. The results show that increasing the number of complexants can enhance the second hyperpolarizability values of the complexes.
STRUCTURAL CHEMISTRY
(2023)
Article
Spectroscopy
Guohua Yao, Shuju Guo, Wenjie Yu, Muhammad Muhammad, Jianguo Liu, Qing Huang
Summary: Astaxanthin is a xanthophyll carotenoid widely found in aquatic animals, with various physiological functions. Different optical isomers of astaxanthin have differences in physiological activities. Raman spectroscopy can distinguish the three optical isomers of astaxanthin.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2021)
Article
Physics, Condensed Matter
Rehana Bano, Sabir Hussain, Muhammad Arshad, Abdul Rauf, Tariq Mahmood, Khurshid Ayub, Mazhar Amjad Gilani
Summary: In this study, the effects of lanthanum doping on corannulene buckybowls were investigated through DFT simulations. The results revealed that the designed complexes exhibited stable thermodynamic properties and significantly reduced HOMO-LUMO energy gaps. The maximum charge transfer and presence of various interactions in the complexes were also observed. The complexes showed transparency in the UV-Visible region and had strong nonlinear optical responses, making them potentially useful for optical applications.
PHYSICA B-CONDENSED MATTER
(2022)
Article
Clinical Neurology
Yaira Hamama-Raz, Robin Goodwin, Elazar Leshem, Menachem Ben-Ezra
Summary: This study examined the psychological predictors and impact on Adjustment Disorder (AjD) after the second COVID-19 lockdown in Israel. Results showed that sex, COVID-19 occupational related stress, probable depression, and uncertainty were significant predictors of AjD after the lockdown.
JOURNAL OF AFFECTIVE DISORDERS
(2021)
Article
Nanoscience & Nanotechnology
Wei-Ting Chen, Ting-Yu Yen, Yang-Hao Hung, Yu-Hsiang Huang, Shang-Jui Chiu, Kuang-Yao Lo
Summary: A model based on the simplified bond hyperpolarizability model (SBHM) is developed to analyze the anisotropic reflective second harmonic generation (Ani-RSHG) on a three-period stacked Si/Si1-x Ge (x) multilayer. The model is used to study the change in Ge distribution and its gradient in depth by analyzing the Ani-RSHG spectra of the as-grown and annealed samples. The results demonstrate the potential of the model for characterizing the concentration distribution in stacked multilayered thin films.
Article
Materials Science, Multidisciplinary
Renato Barbosa-Silva, Mario S. S. Oliveira, Rudson C. Ferreira, Vinicius Manzoni, Eduardo H. L. Falcao, Cid B. de Araujo
Summary: Measurements and theoretical modeling of the second-order optical nonlinearity of two 1,3,4-oxadiazole derivatives, Oxa-4-Py and DiOxaBn-2-Tio, were reported. The dynamic and static first hyperpolarizability values were measured using the hyper-Rayleigh scattering technique and a density functional method. The results showed that the first hyperpolarizability of DiOxaBn-2-Tio is approximately 30% larger than that of Oxa-4-Py.
Article
Chemistry, Multidisciplinary
Rehana Bano, Muhammad Arshad, Tariq Mahmood, Khurshid Ayub, Ahsan Sharif, Shagufta Perveen, Sobia Tabassum, Jucai Yang, Mazhar Amjad Gilani
Summary: The study designed a series of alkaline earthide compounds based on superalkali metals, confirming their alkaline earthide nature and thermodynamic stability, which is significant for enhancing the nonlinear optical response.
JOURNAL OF PHYSICS AND CHEMISTRY OF SOLIDS
(2022)
Article
Multidisciplinary Sciences
Kahina Abed, Aude Foucher, Dominique Bernard, Emmanuelle Tancrede-Bohin, Nukhet Cavusoglu
Summary: This study compared the mechanisms of action of all-trans-retinoic acid and retinol on the skin through a one-year longitudinal study and untargeted proteomic analysis. The results showed that these molecules have impacts on biological functions related to skin aging and revealed new functions in glycan metabolism and protein biosynthesis. The study also found a time lapse between molecular and morphological impacts. The temporal proteomics signatures obtained could be used to identify new cosmetic compounds of interest.
SCIENTIFIC REPORTS
(2023)
Article
Chemistry, Physical
Faiza Ahsan, Khurshid Ayub
Summary: In this study, the geometric, electronic, and nonlinear optical properties of novel Janus transition metalides AM-J-TM containing alkali metals as a source of excess electrons were investigated. The involvement of alkali metals significantly affected the hyperpolarizability values of the resulting transition metalides. The metalide behavior of these complexes was confirmed through charge transfer analysis and frontier molecular orbital analysis. The designed transition metalides showed excellent nonlinear optical response, suggesting their potential as novel NLO materials.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Physics, Multidisciplinary
Chen Chi-Ting, Wu Lei, Wang Xia, Wang Ting, Liu Yan-Jun, Jiang Jun, Dong Chen-Zhong
Summary: The wave functions, energy levels, and oscillator strengths of B2+ ions and B+ ions were calculated using the relativistic potential model, RCICP. The calculated energy levels were in good agreement with experimental data, with a difference of no more than 0.05%. The calculated oscillator strengths also agreed well with experimental and theoretical results, with a difference of no more than 0.6%.
ACTA PHYSICA SINICA
(2023)
Article
Multidisciplinary Sciences
Emna Rtibi, Benoit Champagne
Summary: The research reveals that strong donors and pi-conjugated spacers have a positive impact on the first hyperpolarizabilities of Lindquist-type organo-imido polyoxometalates. The use of the two-state approximation is suitable for explaining the variations in first hyperpolarizabilities.
Article
Chemistry, Physical
Michal Andrzej Kochman, Krzysztof Palczewski, Adam Kubas
Summary: The study focused on synthesizing 9-cis-RAc and examining the mechanism of photoisomerization reaction, using advanced electronic structure calculations for two polyenic model compounds. It was found that the photoisomerization occurs through a chain-kinking mechanism, and other potential mechanisms were deemed incompatible with simulation results and spectroscopic data.
JOURNAL OF PHYSICAL CHEMISTRY A
(2021)
Article
Chemistry, Physical
Aran Lamaire, Maarten Cools-Ceuppens, Massimo Bocus, Toon Verstraelen, Veronique Van Speybroeck
Summary: Although many molecular dynamics simulations treat atomic nuclei as classical particles, it is necessary to consider nuclear quantum effects (NQEs) when studying proton transfer reactions. In this study, quantum free energy profiles for three typical proton transfers, which properly include NQEs using the path integral formalism, are constructed. The computational cost of the simulations is reduced by using machine learning potentials. The results show a significant deviation between classical/quasi-classical centroid free energy profiles and the exact quantum free energy profile for proton transfers.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Editorial Material
Chemistry, Physical
Veronique Van Speybroeck, Guillaume Maurin
Summary: 700 scientists from 45 countries gathered in Dresden for the first time since the start of the COVID-19 pandemic to share their latest findings on metal-organic frameworks and open frameworks compounds.
Article
Chemistry, Physical
Sander Vandenhaute, Maarten Cools-Ceuppens, Simon DeKeyser, Toon Verstraelen, Veronique Van Speybroeck
Summary: In this study, an incremental learning scheme is proposed to construct accurate and data-efficient machine learning potentials for metal-organic framework materials. The scheme combines equivariant neural network potentials with parallelized enhanced sampling and on-the-fly training to explore and learn the phase space iteratively. With only a few hundred single-point density functional theory evaluations per material, accurate and transferable potentials are obtained, even for flexible frameworks with multiple structurally different phases. This incremental learning scheme is universally applicable and may pave the way to model framework materials in larger spatiotemporal windows with higher accuracy.
NPJ COMPUTATIONAL MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Sander Borgmans, Sven M. J. Rogge, Juul S. De Vos, Pascal van der Voort, Veronique Van Speybroeck
Summary: Soft porous crystals with stimuli responsiveness are widely studied for various applications. However, the structural flexibility in 3D covalent organic frameworks (COFs) is not well understood. This study investigates the factors affecting the phase transformations of diamondoid COFs, including structural decoration, interpenetration, temperature, and guest adsorption. It provides a comprehensive understanding of the design principles for flexible diamondoid COFs.
COMMUNICATIONS CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Jiamin Sun, Himanshu Sekhar Jena, Chidharth Krishnaraj, Kuber Singh Rawat, Sara Abednatanzi, Jeet Chakraborty, Andreas Laemont, Wanlu Liu, Hui Chen, Ying-Ya Liu, Karen Leus, Henk Vrielinck, Veronique Van Speybroeck, Pascal Van Der Voort
Summary: Four highly porous covalent organic frameworks (COFs) containing pyrene units were prepared and explored for photocatalytic H2O2 production. Experimental studies and density functional theory calculations showed that the pyrene unit has higher activity for H2O2 production compared to bipyridine and (diarylamino)benzene units. The distribution of pyrene units over a large surface area of COFs was found to be crucial for catalytic performance.
ANGEWANDTE CHEMIE-INTERNATIONAL EDITION
(2023)
Article
Multidisciplinary Sciences
Veronique Van Speybroeck
Summary: The article discusses the capability of current modelling strategies to simulate dynamic phenomena in realistic nanostructured materials at operating conditions. Nanostructured materials used in applications exhibit a wide range of spatial and temporal heterogeneities. The material's dynamics are influenced by spatial heterogeneities at different scales and the operating conditions. There is a significant gap between the theoretical length-time scales and experimentally relevant scales. The article highlights three key challenges in molecular modelling to bridge this length-time scale gap.
PHILOSOPHICAL TRANSACTIONS OF THE ROYAL SOCIETY A-MATHEMATICAL PHYSICAL AND ENGINEERING SCIENCES
(2023)
Article
Engineering, Environmental
Kim Phan, Sibel Ugduler, Lies Harinck, Ruben Denolf, Martijn Roosen, Galahad O'Rourke, Dirk De Vos, Veronique Van Speybroeck, Karen De Clerck, Steven De Meester
Summary: This study investigates the selective chemical dissolution of elastane from blended textiles using biobased solvents. It was found that tetrahydrofurfuryl alcohol and ?-valerolactone have comparable elastane dissolution capabilities to classical solvents. The selective solvent-based dissolution process saves 60% CO2-eq./kg textile waste compared to incineration, as shown by the LCA study.
RESOURCES CONSERVATION AND RECYCLING
(2023)
Article
Multidisciplinary Sciences
Massimo Bocus, Ruben Goeminne, Aran Lamaire, Maarten Cools-Ceuppens, Toon Verstraelen, Veronique Van Speybroeck
Summary: Proton hopping is a crucial process in zeolite catalysis, but accurately determining its kinetics is challenging. In this study, a machine learning potential (MLP) was trained to accurately reproduce the potential energy surface of proton hopping in H-CHA zeolite at the Density Functional Theory (DFT) level. The MLP significantly speeds up computations and allows for accurate determination of reaction kinetics beyond standard transition state theory. Nuclear quantum effects (NQEs) were found to have a significant impact on proton hopping kinetics, and kinetic isotope effects can be computed without additional training using PIMD simulations with deuterium.
NATURE COMMUNICATIONS
(2023)
Editorial Material
Nanoscience & Nanotechnology
Choongseok Chang, Volker L. Deringer, Kalpana S. Katti, Veronique Van Speybroeck, Christopher M. Wolverton
Summary: Exascale computers, capable of performing 10(18) floating point operations per second, have started to become operational in 2022. The United States has launched Frontier as the first public exascale supercomputer, and Aurora is set to open soon. In China, OceanLight and Tianhe-3 are already operational, while Europe is getting ready to launch JUPITER in 2023. Supercomputers present unprecedented opportunities for modeling complex materials.
NATURE REVIEWS MATERIALS
(2023)
Article
Nanoscience & Nanotechnology
Alexander E. J. Hoffman, Joao Marreiros, Sven M. J. Rogge, Rob Ameloot, Veronique Van Speybroeck
Summary: Mixed-linker zeolitic imidazolate frameworks (ZIFs) are candidate materials for gas separation. The pore size of ZIFs can be regulated by changing the linker content, which affects diffusion and adsorption. The linker distribution in mixed-linker ZIF-8/ZIF-90 is characterized using computational Raman spectroscopy, revealing the impact of hydrogen bonding behavior on the distribution.
ACS APPLIED NANO MATERIALS
(2023)
Article
Chemistry, Multidisciplinary
Amrita Chatterjee, Jiamin Sun, Kuber Singh Rawat, Veronique Van Speybroeck, Pascal van der Voort
Summary: Two donor-acceptor type tetrathiafulvalene (TTF)-based covalent organic frameworks (COFs) were studied as electrodes for symmetric supercapacitors in different electrolytes. The charge storage mechanism of IL electrolyte based supercapacitors depends on the micro pore size and surface charge density of COFs, which can be altered by different electron acceptor building blocks. The combination of these factors enhances the charge storage in highly microporous COFs. DFT calculations support this finding.
Article
Materials Science, Multidisciplinary
Sven M. J. Rogge, Sander Borgmans, Veronique Van Speybroeck
Summary: This article introduces strain engineering as a general approach to rationalize and design materials by modifying their atomic level structure. The potential of strain engineering is demonstrated through two examples, showing how it can be used to design state-of-the-art materials for challenging applications.
Article
Chemistry, Physical
Pieter Cnudde, Michel Waroquier, Veronique Van Speybroeck
Summary: The influence of pore topology and acid strength on the adsorption of (iso)butene in Bronsted acid zeolites has been studied using calculations and simulations. The adsorbed intermediates - physisorbed alkene, chemisorbed carbenium ion, and alkoxide - were evaluated for different zeolite topologies and acid site strengths. The stabilization of the carbenium ion depends on zeolite confinement and acid site strength, while alkoxides are not found at high temperature. The adsorption energies and protonation barriers can be predicted using universal descriptors such as dispersion component and ammonia adsorption energy.
CATALYSIS SCIENCE & TECHNOLOGY
(2023)
Article
Chemistry, Physical
Alexander E. J. Hoffman, Irena Senkovska, Leila Abylgazina, Volodymyr Bon, Veronika Grzimek, Anna Maria Dominic, Margarita Russina, Marvin A. Kraft, Inez Weidinger, Wolfgang G. Zeier, Veronique Van Speybroeck, Stefan Kaskel
Summary: This study utilizes spectroscopic techniques and density functional theory calculations to investigate the vibrational properties of DUT-8(M) materials with different metal nodes (M = Ni, Co, Zn, Cu). Experimental results show that the closed pore phase of the Ni-based compound is stiffer than those containing Co and Zn, while the open pore phase is softer. Theoretical calculations suggest that changing the metal atom mainly affects the phonon modes inducing changes in the paddle wheel unit. These findings provide valuable insights into the flexibility and phase transition mechanism of switchable MOFs.
JOURNAL OF MATERIALS CHEMISTRY A
(2023)
Article
Nanoscience & Nanotechnology
Alexander E. J. Hoffman, Rafikul Ali Saha, Sander Borgmans, Pascal Puech, Tom Braeckevelt, Maarten B. J. Roeffaers, Julian A. A. Steele, Johan Hofkens, Veronique Van Speybroeck
Summary: Metal-halide perovskites (MHPs) have excellent properties for optoelectronic devices, but their long-term stability and phase transitions need to be understood. This study used GIWAXS, Raman spectroscopy, and theoretical calculations to investigate the structural phase transitions and phonon modes in CsPbBr3. The results provided direct evidence for the existence of these phase transitions and identified the Raman active phonon modes. This work enhances our understanding of the structure and lattice dynamics of CsPbBr3 and similar MHPs.