Article
Materials Science, Multidisciplinary
N. D. Woods, M. T. Entwistle, R. W. Godby
Summary: In the context of inhomogeneous one-dimensional finite systems, recent numerical advances have enabled the computation of the exact coupling-constant dependent exchange-correlation kernel within linear response time-dependent density-functional theory, leading to an improved understanding of ground-state total energies derived from ACFDT. Neglecting frequency dependence in the exact functional while considering both one-shot and self-consistent ACFDT calculations has shown to reliably preserve chemical accuracy, with the spatial structure in the exact functional largely remedying self-interaction issues. The implicit orbitals within a self-consistent ACFDT calculation utilizing the adiabatic exact kernel are remarkably similar to the exact Kohn-Sham orbitals, indicating that the spatial dependence of the functional at zero frequency captures the majority of physics for ground-state total energy.
Article
Chemistry, Physical
Andreas Savin, Jacek Karwowski
Summary: The adiabatic connection formalism has been generalized to an arbitrary order, derived from a properly arranged Taylor expansion. The second-order theory is applied to a parabolic confinement system and shows significant improvement compared to the first-order theory.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Materials Science, Multidisciplinary
Essa M. Ibrahim, Ping Tang, Shufeng Zhang
Summary: Random magnetic fields can suppress long-range magnetic ordering by forming magnetic domains, and the size of these domains is determined by the competition among exchange interaction, magnetic anisotropy, and the strength of the random field. The temperature dependence of magnetization in two-dimensional domains for an anisotropic Heisenberg model with a random magnetic field is theoretically investigated, revealing a first-order phase transition characterized by discontinuous magnetization at a critical temperature. This unusual first-order transition persists even in the presence of an external magnetic field weaker than the disorder strength.
JOURNAL OF MAGNETISM AND MAGNETIC MATERIALS
(2022)
Article
Physics, Multidisciplinary
Bo Yang, Bo Xiong, Zilong Liu, Bo Zhang
Summary: In this study, an effective Lindblad equation for describing the dynamics of dressed states in dissipative quantum systems is derived. The elimination of intermediate states leads to the fourth-order Lindblad equation under certain conditions. Through examples of a single atom three-level system and two atoms coupled in a three-level system, the importance of the fourth-order Lindblad equation in exploring dissipative quantum system dynamics is emphasized.
Article
Mechanics
Xianhui Wang, Fanglin Li, Xiaoming Zhang, Jiangong Yu, Hui Qiao
Summary: In this paper, a new method (AILPA) for investigating guided thermoelastic waves in FGM plates is proposed, which shows higher efficiency compared to CLPA. Additionally, a new method for treating adiabatic boundary conditions is developed, and analyses of FGM plates with different fractional orders are conducted.
COMPOSITE STRUCTURES
(2021)
Article
Physics, Multidisciplinary
Serdar uenlue, Hasan BIrcan, Necla cakmak, Cevad Selam
Summary: In this work, we utilize Pyatov's restoration method within the framework of proton-neutron quasiparticle random phase approximation (pn-QRPA) to describe the first-forbidden beta transitions. A detailed procedure for obtaining the energies and wave functions of the first-forbidden excitations is provided. The comparison between the calculated results for different nuclei and the corresponding experimental data demonstrates the applicability of the present approximation.
PRAMANA-JOURNAL OF PHYSICS
(2023)
Article
Physics, Multidisciplinary
Ido Tishby, Ofer Biham, Eytan Katzav
Summary: The analytical results provide insight into the distribution of first hitting times of random walks on random regular graphs, including tail distribution, mean, and variance, as well as the probabilities of different scenarios for the first hitting event. The study shows that in dilute networks the dominant first hitting scenario is backtracking, while in dense networks the dominant scenario is retracing. The results are in excellent agreement with computer simulations, offering valuable information for survival analysis and mortality rate statistics.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2021)
Article
Physics, Multidisciplinary
Ido Tishby, Ofer Biham, Eytan Katzav
Summary: The analytical results show that for random walks on random regular graphs, the trajectories return to the initial node with a certain probability as the number of nodes approaches infinity. The trajectories can be classified into retroceding and non-retroceding scenarios, with excellent agreement between analytical and simulation results.
JOURNAL OF PHYSICS A-MATHEMATICAL AND THEORETICAL
(2021)
Article
Physics, Multidisciplinary
Vittorio De Falco, Emmanuele Battista, John Antoniadis
Summary: In this letter, the analytical expression of coordinate time in terms of the polar angle is derived using the Damour-Deruelle solution. This formula has significant applications in both pulsar timing and gravitational-wave theory.
Article
Chemistry, Multidisciplinary
Zahid Raza, Shehnaz Akhter, Yilun Shang
Summary: The Zagreb connection indices are topological descriptors of graphs based on connection cardinality, used to determine the total electron energy of alternate hydrocarbons. Recent research has found that these indices provide better correlation coefficient values for 13 physico-chemical characteristics of octane isomers compared to basic Zagreb indices. This article presents the expected values formulae for the first Zagreb connection index of random chains and provides extreme and average values for special chains.
FRONTIERS IN CHEMISTRY
(2023)
Article
Physics, Multidisciplinary
Prat Vazquez-Peralta, E. Cota
Summary: In this work, a complete analytic solution is presented for a Hamiltonian representing a three-level system interacting with a bosonic field. The Hamiltonian is analyzed by dividing it into blocks, where displaced harmonic oscillators and analytically diagonalizable blocks help generate the eigenenergies and eigenvectors of the system. This work extends a procedure previously applied to a two-level system.
Article
Instruments & Instrumentation
Radislav A. Potyrailo, Brian Scherer, Baokai Cheng, Majid Nayeri, Shiyao Shan, Janell Crowder, Richard St-Pierre, Joleyn Brewer, Renner Ruffalo
Summary: It is commonly expected that existing gas sensors may perform worse in real field conditions due to chemical interference and sensor drift. To overcome this, we are developing first-order gas sensors with independent responses that can self-correct against drift effects. These sensors operate at different frequencies or wavelengths and open opportunities for diverse monitoring applications without frequent maintenance.
APPLIED SPECTROSCOPY
(2023)
Article
Astronomy & Astrophysics
Rajesh Biswas, Asaad Daher, Arpan Das, Wojciech Florkowski, Radoslaw Ryblewski
Summary: We numerically solve the boost-invariant equations of spin hydrodynamics confined to the first-order terms in gradients. The spin equation of state is consistently included in the first order, which relates the spin density tensor to the spin chemical potential. Depending on the form and structure of the spin transport coefficients, we find solutions that are both stable and unstable within the considered evolution times of 10 fm/c. These findings complement the recent identification of stable and unstable modes for perturbed uniform spin systems described by similar hydrodynamic frameworks.
Article
Polymer Science
Leonid I. Klushin, Anna S. Ivanova, Alexey A. Polotsky, Alexander M. Skvortsov
Summary: We investigated the compression and interpenetration properties of two opposing monodisperse polymer brushes under external load using analytical theory and numerical self-consistent field (SCF) approach. We proposed analytical expressions for the brush density profiles and verified them using numerical SCF calculations. Interpenetration of the brushes was quantified using the penetration length, overlap integral Gamma, and the number of brush monomer units in the foreign half-space sigma. The interpenetration parameters were studied as functions of brush separation and external pressure. A theoretical description for the solvent-mediated friction force was also proposed in the low shearing rate regime. The total friction force, including direct brush-brush friction, was found to be expressed in terms of Gamma and sigma. Our SCF data showed that the interpenetration parameters and the total sliding friction force collapsed onto universal master curves when rescaled by (N/sigma)(1/3), where N is the chain length and sigma is the surface grafting density. The kinetic friction coefficient was defined as a function of external pressure, and its universal rescaled behavior was analyzed for the limits of non-draining and free-draining brushes.
Article
Chemistry, Physical
Vishikh Athavale, Hung-Hsuan Teh, Yihan Shao, Joseph Subotnik
Summary: We derive and implement analytic gradients and derivative couplings for TDDFT-1D method, and validate its accuracy by comparing with finite difference values. Furthermore, we demonstrate its capability in locating optimized geometries and minimum-energy crossing points along conical seams.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Inorganic & Nuclear
Megan T. Dumas, Tener F. Jenkins, Justin C. Wedal, Joseph W. Ziller, Filipp Furche, William J. Evans
Summary: The study investigates the reaction of allyl complexes with benzoxazole, resulting in dark red bimetallic isocyanophenolate-bridged complexes. X-ray crystallography reveals their unique structure, and theoretical calculations confirm the origin of their color and reaction mechanism.
Article
Chemistry, Multidisciplinary
Alexandra L. Klodt, Kimberly Zhang, Michael W. Olsen, Jorge L. Fernandez, Filipp Furche, Sergey A. Nizkorodov
Summary: The study found that oxaloacetic acid (OAA) can undergo decarboxylation in the presence of different concentrations of ammonium, shedding light on this process in the atmosphere. In aerosol particles, the concentration of ammonium significantly affects the decarboxylation rate of OAA, while under more acidic conditions the decarboxylation reaction is suppressed.
ACS EARTH AND SPACE CHEMISTRY
(2021)
Article
Chemistry, Physical
Jason M. Yu, Brian D. Nguyen, Jeffrey Tsai, Devin J. Hernandez, Filipp Furche
Summary: This Perspective discusses recent progress in selfconsistent calculations of ground-state energies using the random phase approximation (RPA) within the context of (generalized) Kohn-Sham (KS) density functional theory. The concept of functional selfconsistency (FSC) is introduced along with the development of the generalized KS semicanonical projected RPA (GKS-spRPA) method, which shows improvements in densities, binding energy curves, and molecular properties. The differences between KS and interacting densities without FSC and the performance of GKS-spRPA suggest that the KS potential for explicitly potential-dependent density functionals should be defined via the FSC condition.
JOURNAL OF CHEMICAL PHYSICS
(2021)
Article
Chemistry, Physical
Jared P. Bruce, Kimberly Zhang, Sree Ganesh Balasubramani, Amanda R. Haines, Randima P. Galhenage, Vamsee K. Voora, Filipp Furche, John C. Hemminger
Summary: Liquid jet X-ray photoelectron spectroscopy was used to investigate changes in the local electronic structure of acetic acid in aqueous solutions induced by solvation effects. The comparison shows that a single water molecule can describe the photo-electron Delta BE of acetic acid while at least 20 water molecules are required for the conjugate base, acetate, in aqueous solutions.
JOURNAL OF PHYSICAL CHEMISTRY B
(2021)
Article
Chemistry, Multidisciplinary
Conrad A. P. Goodwin, Sierra R. Ciccone, Samuel Bekoe, Sourav Majumdar, Brian L. Scott, Joseph W. Ziller, Andrew J. Gaunt, Filipp Furche, William J. Evans
Summary: New coordination environments for Np(III) and Pu(III) are reported based on pilot studies, with U(III) also studied in the same context. Complexes obtained through reactions showed different electron configurations for U(III), Np(III), and Pu(III).
CHEMICAL COMMUNICATIONS
(2022)
Article
Chemistry, Physical
Brian D. Nguyen, Devin J. Hernandez, Emmanuel Flores, Filipp Furche
Summary: A multivariate adiabatic connection (MAC) framework is proposed to describe dispersion interactions in a system of non-overlapping monomers. The MAC allows a rigorous separation of induction and dispersion effects by constraining the density to the physical ground-state density of the supersystem. It is found that many-body perturbation theory violates dispersion size-consistency, while random phase approximation-type methods preserve it.
ELECTRONIC STRUCTURE
(2022)
Article
Chemistry, Inorganic & Nuclear
Justin C. Wedal, Joseph W. Ziller, Filipp Furche, William J. Evans
Summary: Heteroleptic U(III) complexes supported by bis(cyclopentadienyl) frameworks were synthesized and evaluated as precursors to U(II) complexes. The complexes were compared with other related compounds, and their electrochemical behavior was studied, revealing redox couples for U(IV)/U(III) and U(III)/U(II) transitions. The targeted U(II) complexes were analyzed using density functional theory, showing a 5f(3)6d(1) electron configuration as the ground state in each case.
INORGANIC CHEMISTRY
(2022)
Correction
Chemistry, Physical
Jefferson E. Bates, Maximillian C. Heiche, Jiashu Liang, Filipp Furche
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Krishnendu Kundu, Jessica R. K. White, Samuel A. Moehring, Jason M. Yu, Joseph W. Ziller, Filipp Furche, William J. Evans, Stephen Hill
Summary: By controlling the degree of s-orbital mixing in molecules, a large spin hyperfine interaction can be achieved, leading to a 9 GHz clock transition and increased phase memory time. These findings suggest new strategies for the development of molecular quantum technologies.
Article
Chemistry, Inorganic & Nuclear
William N. G. Moore, Jessica R. K. White, Justin C. Wedal, Filipp Furche, William J. Evans
Summary: The utility of gamma irradiation for generating unstable, low oxidation state molecular species containing rare-earth metal ions in frozen solution has been examined. The method was evaluated by irradiating Ln(III) precursors (Ln = Sc, Y, and La) in a solid matrix of 2-methyltetrahydrofuran at 77 K with a 700 keV 137Cs source to generate free electrons capable of reducing the Ln(III) species.
INORGANIC CHEMISTRY
(2022)
Article
Chemistry, Physical
Robin Grotjahn, Filipp Furche, Martin Kaupp
Summary: For more than a decade, it has been known that the gauge variance of the kinetic energy density tau affects the magnetic orbital rotation Hessian used in linear-response time-dependent density functional theory (TDDFT). This study highlights the pronounced effects of tau-dependent exchange-correlation functionals on excitation energies, especially for the M06-2X functional and some other meta-generalized gradient approximations (mGGAs). Restoring gauge invariance significantly reduces errors in excitation energies obtained with M06-2X, indicating the importance of imposing gauge invariance for different mGGA-based functionals.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Sree Ganesh Balasubramani, Vamsee K. Voora, Filipp Furche
Summary: This study presents an analytical implementation of static dipole polarizabilities within the generalized Kohn-Sham semicanonical projected random phase approximation (GKS-spRPA) method. By deriving the general second-order analytical derivatives of the GKS-spRPA energy functional and using a Lagrangian approach, the computational requirements of the method are similar to those for GKS-spRPA ground state energies. The GKS-spRPA polarizabilities are assessed for various molecules and clusters, and the method is found to effectively address the limitations of semilocal density functional approximations and post-PBE RPA polarizabilities.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Amanda B. Chung, Dmitrij Rappoport, Joseph W. Ziller, Roger E. Cramer, Filipp Furche, William J. Evans
Summary: Investigation of the reduction chemistry of Nd(NR2)(3) under N2 has revealed connections between the in situ Ln(III)/K reductions of N-2 forming side-on bound complexes and the Ln(II)-based reductions by Sc, Gd, and Tb forming end-on bound complexes. The study suggests a link between Ln(III)/K reductions and Ln(II) reductions depending on solvent, temperature, presence of a chelate, and rare-earth metal.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Inorganic & Nuclear
Lauren M. Anderson-Sanchez, Jason M. Yu, Joseph W. Ziller, Filipp Furche, William J. Evans
Summary: The sterically bulky aryloxide ligand OAr* has been used to synthesize thermally stable Ln(II) complexes across the lanthanide series. Reduction of Ln(III) precursors Ln(OAr*)3 with potassium graphite and 2.2.2-cryptand yielded the Ln(II) complexes. The La and Ce complexes were challenging to isolate but could be obtained with the use of 18-crown-6 as a potassium chelator.
INORGANIC CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Dmitrij Rappoport, Samuel Bekoe, Luke Nambi Mohanam, Scott Le, Naje' George, Ziyue Shen, Filipp Furche
Summary: This article presents the design and implementation of libkrylov, an open-source library for solving matrix-free eigenvalue, linear, and shifted linear equations using Krylov subspace methods. The key features of libkrylov include flexible API design, modular structure, and integration with specialized matrix-vector evaluation engines.
JOURNAL OF COMPUTATIONAL CHEMISTRY
(2023)