Article
Chemistry, Physical
Antoine Marie, Fabris Kossoski, Pierre-Francois Loos
Summary: In this study, the structure of the energy landscape of variational CC is explored and compared with the traditional version. By investigating two model systems under weak and strong correlation conditions, the performance of variational pCCD (VpCCD) and traditional pCCD is evaluated against their CI equivalent.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Anders Hutcheson, Alexander Christian Paul, Rolf H. Myhre, Henrik Koch, Ida-Marie Hoyvik
Summary: Coupled cluster models are effective in describing ground and excited state potential energy surfaces of photoswitchable systems, especially when triple excitations are included. Molecular geometry and basis set significantly impact the vertical excitation energies for the lowest excited states. Efficient implementations of coupled cluster models can provide valuable information for preliminary studies of photoswitchable systems before more complex dynamics approaches are pursued.
JOURNAL OF COMPUTATIONAL CHEMISTRY
(2021)
Article
Chemistry, Multidisciplinary
Ruili Shi, Zhi Zhao, Xiaoming Huang, Pengju Wang, Yan Su, Linwei Sai, Xiaoqing Liang, Haiyan Han, Jijun Zhao
Summary: The study used the comprehensive genetic algorithm to explore the lowest-energy structures of hydrated calcium ion clusters. The results revealed changes in the arrangement and interactions of water molecules as the cluster size increased.
FRONTIERS IN CHEMISTRY
(2021)
Review
Chemistry, Multidisciplinary
F. D. Vila, J. J. Kas, J. J. Rehr, K. Kowalski, B. Peng
Summary: Green's function methods provide a powerful framework for treating electron correlation in both excited states and x-ray spectra. A non-perturbative real-time coupled-cluster cumulant Green's function approach has been introduced to extend conventional methods, yielding better results for x-ray photoemission spectra and binding energies. This approach includes orthogonality and shake-up effects, enhancing the x-ray absorption spectrum near the edge.
FRONTIERS IN CHEMISTRY
(2021)
Article
Chemistry, Physical
Sebastian M. Thielen, Manuel Hodecker, Julia Piazolo, Dirk R. Rehn, Andreas Dreuw
Summary: The study introduces the core-valence separation (CVS) approximation applied to unitary coupled-cluster (UCC) theory for calculating core-excited states and simulating x-ray absorption spectroscopy (XAS). Results from CVS-UCC are compared to algebraic-diagrammatic construction methods and experimental data, showing its potential as a new approach for XAS calculations.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Faruk Salihbegovic, Alejandro Gallo, Andreas Grueneis
Summary: We conducted a study on the two-dimensional circular quantum dot model Hamiltonian using various quantum chemical ab initio methods. Ground and excited state energies were calculated using different levels of perturbation theories, including the coupled cluster method. We proposed a scheme to compute the required Coulomb integrals in real space and employed a semianalytic solution for the integral over the Coulomb kernel near the singularity. Additionally, we found that the remaining basis set incompleteness error for two-dimensional quantum dots decreases with the inverse number of virtual orbitals, enabling us to extrapolate to the complete basis set limit energy. By adjusting the harmonic potential parameter, we modulated the correlation strength and investigated the predicted ground and excited state energies.
Article
Chemistry, Physical
Nicolas Foglia, Bernardo De Souza, Dimitrios Maganas, Frank Neese
Summary: This work presents a computational approach that incorporates vibrational effects in the computations of magnetic circular dichroism (MCD) spectra. The method combines modeling of absorption, fluorescence, and phosphorescence spectra with a new technique to calculate MCD intensities. The implementation utilizes a path integral approach to compute nuclear dynamics and quasi-degenerate perturbative theory to include the perturbation of an external magnetic field.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Isuru R. Ariyarathna, Evangelos Miliordos
Summary: High-level electronic structure calculations were conducted to investigate neutral lithium, sodium, and potassium complexes with ethylenediamine and crown ether molecules, revealing different electron orbital characteristics and shell models for each type of complex. The study found that despite the similar nature of electrides (metal crown ether sandwich aggregates) and expanded metals (metal ammonia aggregates), their electronic band structures are expected to differ significantly. Li(15-crown-5) was identified as the only complex adopting a shell model similar to that of metal ammonia complexes, positioning the metal in the center of the crown ether.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Nuno M. S. Almeida, Timothe R. L. Melin, Angela K. Wilson
Summary: High level multireference calculations were performed on LuF, including 132 states and discussing dissociation channels and excited states. Various methods were used to calculate dissociation energies at different theory levels, with the best prediction obtained using coupled-cluster methods and including a relativistic treatment of electrons.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Multidisciplinary
Maria Drosou, Dimitrios A. Pantazis
Summary: The debate over the electronic and geometric structures of the water-oxidizing complex of photosystem II before dioxygen evolution is ongoing. Recent studies have presented contradictory redox formulations for the Mn4CaOx cofactor in the S-3 state, leading to uncertainty about the O-O bond formation in the catalytic cycle. By employing advanced theoretical calculations, researchers were able to evaluate different models for the S-3 state of the oxygen-evolving complex and assess the accuracy of lower-level theoretical approaches.
CHEMISTRY-A EUROPEAN JOURNAL
(2021)
Article
Chemistry, Inorganic & Nuclear
Fitzerald Hujon, Richard H. Duncan Lyngdoh, R. Bruce King
Summary: The passage discusses the characteristics of diiron paddlewheel- or lantern-type complexes, including their Fe-Fe bond lengths and bond orders. DFT studies on truncated models and various model complexes with different ligands were conducted to predict ground state spin multiplicities and Fe-Fe bond lengths. The results show high spin multiplicities in ground states, variations in bond orders, and deviations from symmetry in trigonal and tetragonal complexes.
EUROPEAN JOURNAL OF INORGANIC CHEMISTRY
(2021)
Article
Optics
Isuru R. Ariyarathna, Evangelos Miliordos
Summary: High-level quantum calculations were used to analyze the lowest energy electronic states of TcO+ and RhO+. The potential energy curves, bond lengths, excitation energies, vibrational frequencies, and bonding patterns were reported. The results were compared with neighboring species.
JOURNAL OF QUANTITATIVE SPECTROSCOPY & RADIATIVE TRANSFER
(2022)
Article
Chemistry, Multidisciplinary
Maximilian Muhr, Raphael Buhler, Hao Liang, Jonas Gilch, Christian Jandl, Samia Kahlal, Jean-Yves Saillard, Christian Gemel, Roland A. Fischer
Summary: Treatment of [Ru(COD)(MeAllyl)(2)] and [Ru(COD)(COT)] with GaCp* under hydrogenolytic conditions leads to the formation of reactive intermediates capable of activating Si-H or C-H bonds. The structures and properties of the resulting complex compounds [Ru(GaCp*)(3)(SiEt3)H-3] (1) and [Ru(GaCp*)(3)(C7H7)H-3] (2) have been investigated and characterized.
CHEMISTRY-A EUROPEAN JOURNAL
(2022)
Article
Chemistry, Physical
Yorick L. A. Schmerwitz, Aleksei Ivanov, Elvar O. Jonsson, Hannes Jonsson, Gianluca Levi
Summary: A variational, time-independent density functional approach is used to accurately describe the energy surfaces of twisting and pyramidal distortion in ethylene, even with the use of a semilocal functional approximation. The findings suggest the possibility of using a single determinant time-independent density functional approach for simulating nonadiabatic dynamics in large systems.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2022)
Article
Physics, Nuclear
A. Nesterov, Yu A. Lashko, V. S. Vasilevsky
Summary: This study examines the properties of bound and resonance states in the Be-9(Lambda) nucleus using a three-cluster 2 alpha + Lambda microscopic model. It analyzes the influence of cluster polarization on the energy and widths of resonance states in Be-9(Lambda) and on elastic and inelastic He-5(Lambda) + alpha scattering.
Article
Chemistry, Physical
Marek Bukowicki, Maria L. Ekiel-Jezewska
Article
Physics, Multidisciplinary
Magdalena Gruziel, Krishnan Thyagarajan, Giovanni Dietler, Andrzej Stasiak, Maria L. Ekiel-Jezewska, Piotr Szymczak
PHYSICAL REVIEW LETTERS
(2018)
Article
Chemistry, Physical
Maria L. Ekiel-Jezewska, Zbigniew Adamczyk, Jerzy Blawzdziewicz
JOURNAL OF PHYSICAL CHEMISTRY C
(2019)
Article
Mechanics
Nejiba Ghalya, Antoine Sellier, Maria L. Ekiel-Jezewska, Francois Feuillebois
JOURNAL OF FLUID MECHANICS
(2020)
Article
Mechanics
Krzysztof Kuczera, Gouri S. Jas, Maria L. Ekiel-Jezewska, Yevgen Melikhov
Article
Mechanics
Pawel J. Zuk, Agnieszka M. Slowicka, Maria L. Ekiel-Jezewska, Howard A. Stone
Summary: A numerical study of an elastic fiber in a shear flow at low Reynolds number was conducted, where different theoretical schemes were applied to understand the motion of the fiber. The results showed that the bending, curling, and rotation of the fiber, depending on its length and stiffness, determined the overall motion and shape evolution. The numerical findings were further supported by an interpretation using an elastica model.
JOURNAL OF FLUID MECHANICS
(2021)
Article
Physics, Multidisciplinary
Chris Trombley, Maria L. Ekiel-Jezewska
Summary: This study investigates the dynamics of two charged point particles settling in a Stokes flow, focusing on stable doublets formed by specific initial relative positions and system parameters. The research identifies various stable stationary states and their stability properties, showing infinite attractors for each state. Systems with multiple stable stationary states are found, with different conditions for overlapping and non-overlapping stable states based on the particle sizes and Stokes velocities.
JOURNAL OF PHYSICS COMMUNICATIONS
(2021)
Article
Physics, Multidisciplinary
Agnieszka M. Slowicka, Nan Xue, Pawel Sznajder, Janine K. Nunes, Howard A. Stone, Maria L. Ekiel-Jezewska
Summary: The study focuses on the three-dimensional dynamics of flexible fibers in shear flow, showing that fibers rotate along effective Jeffery orbits and become aligned with the flow direction in the flow-vorticity plane. Compressional buckling of fibers can occur in a short time, indicating differences between local and compressional bending and their dependence on the initial fiber orientation and the bending stiffness ratio A.
NEW JOURNAL OF PHYSICS
(2022)
Article
Multidisciplinary Sciences
Pawel Sznajder, Bogdan Cichocki, Maria Ekiel-Jezewska
Summary: We qualitatively investigate a stationary state of a non-Brownian sedimenting suspension. By analyzing the BBGKY hierarchy derived from the Liouville equation, we find that the assumption of plasma-like screening relations can eliminate some long-range terms in the hierarchy, but it does not lead to integrable solutions for correlation functions. This suggests the breaking of translational symmetry in the system, allowing the development of a non-uniform structure to suppress velocity fluctuations and limit the range of correlations.
Article
Biochemistry & Molecular Biology
Radost Waszkiewicz, Maduni Ranasinghe, Jonathan M. Fogg, Daniel J. Catanese Jr, Maria L. Ekiel-Jezewska, Maciej Lisicki, Borries Demeler, Lynn Zechiedrich, Piotr Szymczak
Summary: DNA in cells is organized in negatively supercoiled loops, allowing it to adopt a wide variety of 3-D shapes. The interplay of negative supercoiling, looping, and shape influences DNA's activity and properties. Through analytical ultracentrifugation, we found that the hydrodynamic properties of DNA strongly depend on circularity, loop length, and degree of negative supercoiling. By combining linear elasticity theory with hydrodynamic calculations, we could predict and interpret these properties.
NUCLEIC ACIDS RESEARCH
(2023)
Correction
Chemistry, Physical
Magdalena Gruziel-Slomka, Pawel Kondratiuk, Piotr Szymczak, Maria L. Ekiel-Jezewska
Article
Physics, Fluids & Plasmas
Agnieszka M. Slowicka, Howard A. Stone, Maria L. Ekiel-Jezewska
Article
Chemistry, Physical
Marek Bukowicki, Maria L. Ekiel-Jezewska
Article
Chemistry, Physical
Magdalena Gruziel-Slomka, Pawel Kondratiuk, Piotr Szymczak, Maria L. Ekiel-Jezewska
Article
Chemistry, Physical
Maria L. Ekiel-Jezewska, Eligiusz Wajnryb
PHYSICOCHEMICAL PROBLEMS OF MINERAL PROCESSING
(2018)