Article
Chemistry, Physical
Sladana Dordevic, Slavko Radenkovic
Summary: In this work, we demonstrate that both neutral BeB8 and MgB8 exhibit a singlet ground state umbrella-like form. The stability, electronic structure, and aromaticity of these target molecules are compared. The magnetically induced current densities show that both BeB8 and MgB8 are double aromatic systems with different spatial distribution of current density patterns.
Article
Chemistry, Physical
Mads-Peter V. Christiansen, Nikolaj Ronne, Bjork Hammer
Summary: Modeling and understanding material properties from first principles requires knowledge of atomistic structure. The rise of machine learning techniques in materials science has accelerated structure searches. This paper introduces the customizable Atomistic Global Optimization X (AGOX) framework and code for efficient building and testing of global optimization algorithms.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Biochemistry & Molecular Biology
Fedor Y. Naumkin
Summary: Complexes of metal atoms with organic molecules are a class of systems with numerous applications, such as in metal-organic interfaces and organometallic chemistry. This study systematically investigates complexes with second-group metals, focusing on their structure, stability, charge distribution, polarity, and IR spectra. Three groups of isomers with different stability and physisorption or chemisorption characteristics are identified. Nonadditive stabilization in ternary systems and shape alterations of the aromatic component for different isomers and system sizes are also observed.
Article
Chemistry, Physical
Hyeri Yoo, Kyeong-Seok Lee, Sahn Nahm, Gyu Weon Hwang, Sangtae Kim
Summary: The study investigates the impact of ligand chemistry and coverage on InP surface properties using density functional theory calculations, revealing that different ligands result in different crystal shapes and surface states are altered upon ligand adsorption.
APPLIED SURFACE SCIENCE
(2022)
Article
Chemistry, Physical
David Ochoa-Resendiz, Antonio Gamboa-Suarez, Ramon Hernandez-Lamoneda
Summary: This article presents a detailed theoretical characterization of the structure and interactions in dichlorine clathrate hydrate cages, including the influence of halogen bonding and rotational motion. Monte Carlo simulations and energy decomposition analysis are used to further understand these effects.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Juan J. J. Aucar, Alejandro F. F. Maldonado, Juan I. I. Melo
Summary: In this work, relativistic corrections to the electric field gradient (EFG) are presented, including spin-dependent corrections for the first time. The results show that these new corrections significantly improve the performance of the existing method and are in close agreement with calculations at the four-component Dirac-Hartree-Fock (4c-DHF) level. The accuracy of the EFG values obtained with this new method allows for the analysis of the electronic origin of relativistic effects using well-known nonrelativistic operators.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Biochemistry & Molecular Biology
Emilia Valenca Ferreira de Aragao, Luca Mancini, Noelia Faginas-Lago, Marzio Rosi, Dimitrios Skouteris, Fernando Pirani
Summary: In this study, a new theoretical approach is proposed to investigate the reaction between the cyano radical and cyanoacetylene molecule. The approach combines statistic RRKM calculations with a semiempirical analysis to derive the rate coefficient for this reaction. The obtained rate coefficient is compared with previous theoretical and experimental investigations, revealing the strengths and weaknesses of the new approach.
Article
Chemistry, Physical
Jing Shang, Congxin Xia, Chun Tang, Chun Li, Yandong Ma, Yuantong Gu, Liangzhi Kou
Summary: The bending deformation of AgBiP2Se6 monolayers can manipulate the polarization direction and domain size, significantly improving the ferroelectric stability. This mechano-ferroelectric coupling represents a new mechanism for stabilization and polarization flip in 2D ferroelectrics, with potential applications in next-generation non-volatile storage devices.
NANOSCALE HORIZONS
(2021)
Article
Chemistry, Physical
Sunila Bakhsh, Xiaohui Liu, Yanyong Wang, Lixin He, Xinguo Ren
Summary: In this study, a two-step approach was used to investigate the structural and electronic properties of beryllium and magnesium clusters. New globally lowest-energy isomer structures were identified, and it was found that van der Waals interactions have a stronger influence on magnesium clusters. A close relationship between structural stability and chemical hardness was revealed for both types of clusters through a second-difference analysis of binding energies and HOMO-LUMO gaps.
JOURNAL OF PHYSICAL CHEMISTRY A
(2021)
Article
Materials Science, Multidisciplinary
Lu Wu, Vasyl O. Kharchenko, Xianggang Kong, Dmitrii O. Kharchenko
Summary: This article investigates the stability of small vacancy clusters in zirconium-based alloys with small concentration of alloying additions through ab-initio calculations. The study analyzes the formation energy of different size vacancy clusters and the binding energy between solute and vacancy clusters to understand the ability of alloying elements to localize small vacancy clusters. Insights are provided into the effect of alloying elements on vacancy clustering in zirconium-based alloys.
JOURNAL OF NUCLEAR MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
S. S. Huang, H. Q. Guan, Z. H. Zhong, M. Miyamoto, Q. Xu
Summary: Recent studies have found that equiatomic CoCrFeMnNi high-entropy alloy (HEA) exhibits excellent mechanical properties and irradiation resistance. However, when subjected to neutron irradiation, helium (He) is always generated as a byproduct. This study compares the irradiation resistance of thin-film CoCrFeMnNi HEA samples irradiated with He ions at 773 K to that of stainless steel 304 (SS304), which has the same crystal structure. Both alloys showed the formation of He bubbles during irradiation, but the CoCrFeMnNi HEA had a lower He bubble density compared to SS304 under the same exposure conditions. First-principles calculations were used to simulate the effect of He on the formation of vacancy clusters in the CoCrFeMnNi HEA, and the results demonstrated that the presence of He significantly enhanced the stability of vacancy clusters. Therefore, even in the CoCrFeMnNi HEA, irradiation resulted in the formation of stable He-vacancy clusters, which decreased the irradiation resistance.
JOURNAL OF NUCLEAR MATERIALS
(2022)
Article
Biochemical Research Methods
A. S. Maldonado, R. Faccio, S. B. Ramos
Summary: The vibrational and thermal properties of small Ni clusters are investigated, with a focus on the size and geometry effects. The energy comparison between the Oh and Ih geometries shows that the Ih isomers have lower energy. Molecular dynamics simulations reveal the transformation from the initial Oh geometries to the corresponding Ih ones. The vibrational density of states and heat capacity are calculated and compared with the Ni FCC bulk counterpart.
JOURNAL OF MOLECULAR GRAPHICS & MODELLING
(2023)
Article
Spectroscopy
Zhen Wang, Yugao Xu, Wenqin Li, Tao Lu, Gang Feng
Summary: In this study, the 1,4-pentadien-3-ol and its monohydrate were characterized using microwave spectroscopy and theoretical computations. The research revealed the characteristics of hydrogen bonds in the compounds.
SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY
(2022)
Article
Chemistry, Multidisciplinary
Sarvesh Kumar Pandey, Elangannan Arunan
Summary: The study explores the impact of OH/SH substituents on the stability and aromaticity of benzene rings, acting as modulators when forming intramolecular hydrogen bonds. Different OH/SH substituents forming intramolecular hydrogen bonds play a vital role in modulating the aromaticity, with varying effects on the cyclic 4n+2 pi-electron delocalization. The aromaticity indices show small variations, indicating the modulatory effect of the pi-electron structure based on the substituent effect through intramolecular hydrogen bond formation.
Article
Chemistry, Applied
Thibault Pariat, Pauline M. Verite, Denis Jacquemin, Julien Massue, Gilles Ulrich
Summary: A dual-emissive fluorophore, HBBODipic, with an Excited-State Intramolecular Proton Transfer (ESIPT) process has been described. It has been used for generating panchromatic white-emission and ratiometric detection of substrates.
Article
Chemistry, Physical
Eva Zunzunegui-Bru, Elisabeth Gruber, Teresa Lazaro, Massimiliano Bartolomei, Marta I. Hernandez, Jose Campos-Martinez, Tomas Gonzalez-Lezana, Stefan Bergmeister, Fabio Zappa, Paul Scheier, Ricardo Perez de Tudela, Javier Hernandez-Rojas, Jose Breton
Summary: In this study, we have observed the largest ordered structure of helium atoms surrounding a monatomic impurity using a newly developed technique. The investigation of HeNCa2+ clusters formed in helium nanodroplets shows magic numbers at N = 12, 32, 44, and 74, indicating the presence of well-ordered shells surrounding the calcium dication. These shells exhibit Mozartkugellike structures and consist of different shapes such as an icosahedron, dodecahedron, and icosidodecahedron.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Biochemistry & Molecular Biology
Cahit Orek, Massimiliano Bartolomei, Cecilia Coletti, Niyazi Bulut
Summary: Gold(I) metal complexes have potential applications as therapeutic agents, and graphene and its derivatives show promise as drug nanocarriers. In this study, the adsorption of a gold(I) N-heterocyclic monocarbene on graphene was computationally investigated. The study found that the drug adsorption on graphene was very favorable, mainly driven by dispersion and electrostatic attraction.
Article
Biochemistry & Molecular Biology
Pedro M. C. Matias, Joana F. M. Sousa, Eva F. Bernardino, Joao P. Vareda, Luisa Duraes, Paulo E. Abreu, Jorge M. C. Marques, Dina Murtinho, Artur J. M. Valente
Summary: Toxic heavy metals, commonly found in dangerous concentrations in wastewater, can be effectively removed by chitosan and its derivatives. Among the synthesized reduced chitosan derivatives (RCDs), RCD3 exhibited the highest adsorption efficiency for Cu(II) under optimal conditions. Molecular dynamics simulations revealed that RCDs had stronger interactions with Cu(II) compared to chitosan, resulting in improved adsorption.
Article
Chemistry, Multidisciplinary
Stefano Falcinelli, Franco Vecchiocattivi, Fernando Pirani
Summary: The authors propose an optical potential formulation to describe the topology of prototypical chemi-ionization reactions of excited state neon with argon, nitrogen, and ammonia molecules. The stereo-dynamic topology of chemi-ionizations is related to the centrifugal barrier of colliding reactants, which acts as a selector of the orbital quantum number effective for reaction in a state-to-state treatment. The accurate formulation of the Optical interaction potentials obtained by the combined analysis of scattering and spectroscopic experimental findings sheds light on the structure, energy, and angular momentum couplings of the precursor state controlling the stereo-dynamics of prototypical chemi-ionization reactions.
COMMUNICATIONS CHEMISTRY
(2023)
Article
Chemistry, Physical
Esther Garcia-Arroyo, Jose Campos-Martinez, Massimiliano Bartolomei, Marta I. Hernandez, Fernando Pirani, Nadine Halberstadt
Summary: In this study, an adiabatic separation of the rotational motion of H2 molecules is applied to build effective pseudoatom-ion potentials for (H2)nNa+/Cl- clusters. The accuracy of this adiabatic model is confirmed by comparing with simulations that explicitly describe molecular rotations. Additionally, differences in cluster stabilities and coordination shells are found depending on the spin isomer, particularly for anionic clusters.
Article
Optics
Qizhen Hong, Loriano Storchi, Massimiliano Bartolomei, Fernando Pirani, Quanhua Sun, Cecilia Coletti
Summary: Rate coefficients for vibrational energy transfer between molecular nitrogen and hydrogen were calculated using a mixed quantum-classical method. These data are crucial for simulating discharges in N-2/H-2 plasma and atmospheric/interstellar medium chemistry. The obtained rates differed significantly from those predicted by first-order perturbation theories. Additionally, different Machine Learning models based on Gaussian Process or Neural Network techniques were analyzed to generate complete datasets of inelastic scattering rate coefficients.
EUROPEAN PHYSICAL JOURNAL D
(2023)
Article
Biochemistry & Molecular Biology
Luca Schio, Michele Alagia, Robert Richter, Vitali Zhaunerchyk, Stefano Stranges, Fernando Pirani, Franco Vecchiocattivi, Marco Parriani, Stefano Falcinelli
Summary: The behavior of nitrosyl chloride (ClNO) exposed to ionizing radiation was studied by directly probing valence-shell electrons in temporal coincidence with ions originating from the fragmentation process of transient ClNO2+. A molecular dication, ClNO2+, was produced through double photoionization with synchrotron radiation. The experiment was conducted at the Elettra Synchrotron Facility of Basovizza (Trieste, Italy) with a linearly polarized light beam parallel to the ClNO molecular beam axis. The double ionization threshold energy of ClNO and six dissociation channels producing various ion pairs have been measured.
Article
Chemistry, Physical
J. R. C. Santos, P. E. Abreu, J. M. C. Marques
Summary: This work investigates the aggregation patterns of curcumin and piperine in different solvents through molecular dynamics simulations. In water, curcumin forms stable dimers while piperine forms less stable dimers. Both curcumin and piperine are soluble in ethanol, resulting in less dimer formation. A mixture of ethanol and water reduces the probability of dimer formation for both compounds. The simulations also reveal the presence of complex structures such as stacks and cages within larger clusters.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
J. R. C. Santos, P. E. Abreu, J. M. C. Marques
Summary: This study investigates the aggregation patterns of curcumin and piperine in different solvents using molecular dynamics simulations. The results show that curcumin forms stable dimers in water, while piperine forms less stable dimers. In ethanol, neither curcumin nor piperine forms dimers. A mixture of ethanol and water reduces the formation of dimers. Larger clusters with stack or cage structures are observed. Each molecule in the cluster exhibits mobility without dissociation.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Review
Chemistry, Physical
Stefano Falcinelli, David Cappelletti, Franco Vecchiocattivi, Fernando Pirani
Summary: The present review focuses on the role of the precursor state in controlling the dynamical evolution of elementary processes. The structures and stability of the precursor state are difficult to characterize quantitatively. The formulation of intermolecular forces and the application of phenomenological methods have provided important insights into understanding the precursor state and its evolution. This information is particularly valuable for chemi-ionization reactions and has the potential to benefit other elementary processes.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Qizhen Hong, Loriano Storchi, Quanhua Sun, Massimiliano Bartolomei, Fernando Pirani, Cecilia Coletti
Summary: In this study, complete data sets of vibration-to-vibration and vibration-to-translation rate coefficients for N-2-N-2 collisions, as well as transport properties, were calculated in the temperature range 100-9000 K. The improved mixed quantum-classical dynamics approach allowed for more realistic and flexible representations, and the role of intra- and intermolecular potentials on the rates and properties was analyzed. The obtained values are reliable and valuable for communities studying nonlocal thermal equilibrium conditions.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Chemistry, Physical
A. Kurnosov, M. Cacciatore, F. Pirani
Summary: In this study, vibration-to-vibration (VV') exchanges between excited CO and unexcited O2 were investigated using the semiclassical coupled state method. The VV' rate constants were calculated based on a recently proposed accurate surface for the N2-O2 system. The results showed good agreement with experimental determinations.
CHEMICAL PHYSICS LETTERS
(2023)
Article
Chemistry, Multidisciplinary
Michal Novotny, Matus Dubecky, Frantisek Karlicky
Summary: This paper investigates the accuracy of different DFT-based computational approaches in calculating the equilibrium lattice constants and exfoliation energy of hexagonal boron nitride (h-BN). The results are compared with experiments and reference QMC calculations to evaluate the accuracy of these computational methods.
JOURNAL OF COMPUTATIONAL CHEMISTRY
(2024)
Article
Chemistry, Multidisciplinary
Luigi Crisci, Federico Coppola, Alessio Petrone, Nadia Rega
Summary: The charge transfer dynamics in asymmetrically substituted indenotetracene molecules upon photo-excitation were investigated using real-time time-dependent density functional theory simulations. The study found that the electron-donating character of the substituents affects the overall electronic energy spacing and ultrafast charge transfer dynamics.
JOURNAL OF COMPUTATIONAL CHEMISTRY
(2024)
Article
Chemistry, Multidisciplinary
Vasilii Korotenko, Hendrik Zipse
Summary: The stability of various radicals and molecules has been studied using different theoretical methods, and good correlations between theoretical calculations and experimental results have been found. The effects of hydrogen bonding interactions on the stability of oxygen-centered radicals have also been investigated.
JOURNAL OF COMPUTATIONAL CHEMISTRY
(2024)
Article
Chemistry, Multidisciplinary
Oleg Egorov, Michael Rey, Dominika Viglaska, Andrei V. Nikitin
Summary: In this work, the rovibrational energy levels of four isotopologues of methylene were calculated using a new accurate ab initio potential energy surface. The accuracy of the calculations was improved by considering scalar relativistic effects, DBOC, and high-order electronic correlations. For the first time, all available experimental rovibrational transitions were reproduced with high accuracy, without any empirical corrections.
JOURNAL OF COMPUTATIONAL CHEMISTRY
(2024)