Author
Erik K. Dalskov
Bio: Erik K. Dalskov is an academic researcher from Lund University. The author has contributed to research in topics: Polarizability & Coupled cluster. The author has an hindex of 2, co-authored 2 publications receiving 1101 citations.
Topics: Polarizability, Coupled cluster
Papers
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Vilnius University1, University of Ferrara2, Aarhus University3, University of Oslo4, Royal Institute of Technology5, Electromagnetic Geoservices6, University of Trieste7, Norwegian Computing Center8, University of Southern Denmark9, University of Santiago de Compostela10, Danske Bank11, Ruhr University Bochum12, Norwegian Meteorological Institute13, Norwegian Defence Research Establishment14, University of Auckland15, Norwegian University of Science and Technology16, Information Technology University17, Technical University of Ostrava18, Linköping University19, Karlsruhe Institute of Technology20, ETH Zurich21, Australian National University22, University of Modena and Reggio Emilia23, Cisco Systems, Inc.24, University of Buenos Aires25, University of Copenhagen26, University of Erlangen-Nuremberg27, Kazimierz Wielki University in Bydgoszcz28, National Scientific and Technical Research Council29, University of Valencia30, Paul Sabatier University31, University of Melbourne32, University of Nottingham33, University of Bristol34, CLC bio35, Princeton University36, La Trobe University37, Clemson University38
TL;DR: Dalton is a powerful general‐purpose program system for the study of molecular electronic structure at the Hartree–Fock, Kohn–Sham, multiconfigurational self‐consistent‐field, Møller–Plesset, configuration‐interaction, and coupled‐cluster levels of theory.
Abstract: Dalton is a powerful general-purpose program system for the study of molecular electronic structure at the Hartree-Fock, Kohn-Sham, multiconfigurational self-consistent-field, MOller-Plesset, confi ...
1,212 citations
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TL;DR: In this paper, the frequency dependence of the polarizabilities is given in terms of the dipole oscillator strength sum rules or Cauchy moments S(-4) and S(-6).
Abstract: Molecular static and dynamic polarizabilities for thirteen small molecules have been calculated using four “black box” ab initio methods, the random phase approximation, RPA, the second-order polarization propagator approximation, SOPPA, the second-order polarization propagator approximation with coupled cluster singles and doubles amplitudes, SOPPA(CCSD), and the coupled cluster singles and doubles linear response function method, CCSDLR. The frequency dependence of the polarizabilities is given in terms of the dipole oscillator strength sum rules or Cauchy moments S(-4) and S(-6). Two basis sets were employed, Sadlej’s medium size polarized basis set and Dunning’s correlation consistent basis set of triple- œ quality augmented by two diffuse functions of each angular momentum (daug-cc-pVTZ). The results are compared to other theoretical results as well as to experimental values for the static polarizabilities, polarizability anisotropies, and Cauchy moments. Frequency-dependent polarizabilities and polarizability anisotropies, calculated at the CCSDLR level using the daug-cc-pVTZ basis set, are presented for five typical laser frequencies. The molecular dipole polarizability enters into the description of many physical and chemical processes, such as the scattering of light by molecules, and intermolecular interactions. Calculated polarizabilities are often used in the verification of experimental data and in the prediction of properties of new chemical species. An accuracy of a few percent in the calculated values is necessary for this purpose. Over the years several methods for the calculation of molecular properties have emerged. Among these are correlated methods, i.e. methods trying to improve on the Hartree-Fock approximation by perturbation theory or a multiconfigurational ansatz, as well as density functional theory (DFT) methods. Most of these methods, however, are only capable of calculating static properties like the static molecular polarizability, excitation energies, and transition moments. A direct comparison of calculated and experimental polarizabilities requires the ability to calculate frequency-dependent polarizabilities since experiments are mostly performed at nonzero frequencies. In an earlier study 1 the performance of some perturbation theory methods in the calculation of static polarizabilities was investigated. In this work, calculations of static and dynamic molecular polarizabilities are presented using four different “black box” methods, that is, methods where the only choices to be made are of the basis set and molecular geometry. These methods are in contrast to multiconfigurational methods where the selection of configurations to be included in the wave function requires considerable experience and might even become impossible for larger molecules. The black box methods, on the other hand, are relatively easy to use also by nonexperts, and their application is, apart from hardware limitations, not restricted to small molecules.
66 citations
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TL;DR: Near-infrared-emissive polymer-carbon nanodots possess two-photon fluorescence; in vivo bioimaging and red-light-emitting diodes based on these PCNDs are demonstrated.
Abstract: Near-infrared-emissive polymer-carbon nanodots (PCNDs) are fabricated by a newly developed facile, high-output strategy. The PCNDs emit at a wavelength of 710 nm with a quantum yield of 26.28%, which is promising for deep biological imaging and luminescent devices. Moreover, the PCNDs possess two-photon fluorescence; in vivo bioimaging and red-light-emitting diodes based on these PCNDs are demonstrated.
620 citations
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Uppsala University1, Max Planck Society2, University of Ferrara3, University of Geneva4, State University of New York System5, University of Minnesota6, University of Rostock7, Katholieke Universiteit Leuven8, Stockholm University9, Lund University10, Harvard University11, Interdisciplinary Center for Scientific Computing12, ETH Zurich13, University of Alcalá14, University College London15, University of Valencia16, University of Vienna17, Imperial College London18, Massey University19, Heidelberg University20, University of Siena21, University of Strasbourg22, Bowling Green State University23, Loughborough University24, Hebrew University of Jerusalem25, National University of Singapore26
TL;DR: The OpenMolcas environment is described and features unique to simulations of spectroscopic and magnetic phenomena such as the exact semiclassical description of the interaction between light and matter, various X-ray processes, magnetic circular dichroism and properties are described.
Abstract: In this Article we describe the OpenMolcas environment and invite the computational chemistry community to collaborate. The open-source project already includes a large number of new developments realized during the transition from the commercial MOLCAS product to the open-source platform. The paper initially describes the technical details of the new software development platform. This is followed by brief presentations of many new methods, implementations, and features of the OpenMolcas program suite. These developments include novel wave function methods such as stochastic complete active space self-consistent field, density matrix renormalization group (DMRG) methods, and hybrid multiconfigurational wave function and density functional theory models. Some of these implementations include an array of additional options and functionalities. The paper proceeds and describes developments related to explorations of potential energy surfaces. Here we present methods for the optimization of conical intersections, the simulation of adiabatic and nonadiabatic molecular dynamics, and interfaces to tools for semiclassical and quantum mechanical nuclear dynamics. Furthermore, the Article describes features unique to simulations of spectroscopic and magnetic phenomena such as the exact semiclassical description of the interaction between light and matter, various X-ray processes, magnetic circular dichroism, and properties. Finally, the paper describes a number of built-in and add-on features to support the OpenMolcas platform with postcalculation analysis and visualization, a multiscale simulation option using frozen-density embedding theory, and new electronic and muonic basis sets.
559 citations
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University of California, Irvine1, Technical University of Denmark2, Dassault Systèmes3, Ruhr University Bochum4, Karlsruhe Institute of Technology5, Technical University of Berlin6, Max Planck Society7, Forschungszentrum Jülich8, Case Western Reserve University9, University of North Carolina at Chapel Hill10, Aarhus University11, California State University, Long Beach12, Kaiserslautern University of Technology13, Tata Institute of Fundamental Research14
TL;DR: This review focuses on recent additions to TURBOMOLE’s functionality, including excited-state methods, RPA and Green's function methods, relativistic approaches, high-order molecular properties, solvation effects, and periodic systems.
Abstract: TURBOMOLE is a collaborative, multi-national software development project aiming to provide highly efficient and stable computational tools for quantum chemical simulations of molecules, clusters, periodic systems, and solutions. The TURBOMOLE software suite is optimized for widely available, inexpensive, and resource-efficient hardware such as multi-core workstations and small computer clusters. TURBOMOLE specializes in electronic structure methods with outstanding accuracy-cost ratio, such as density functional theory including local hybrids and the random phase approximation (RPA), GW-Bethe-Salpeter methods, second-order Moller-Plesset theory, and explicitly correlated coupled-cluster methods. TURBOMOLE is based on Gaussian basis sets and has been pivotal for the development of many fast and low-scaling algorithms in the past three decades, such as integral-direct methods, fast multipole methods, the resolution-of-the-identity approximation, imaginary frequency integration, Laplace transform, and pair natural orbital methods. This review focuses on recent additions to TURBOMOLE's functionality, including excited-state methods, RPA and Green's function methods, relativistic approaches, high-order molecular properties, solvation effects, and periodic systems. A variety of illustrative applications along with accuracy and timing data are discussed. Moreover, available interfaces to users as well as other software are summarized. TURBOMOLE's current licensing, distribution, and support model are discussed, and an overview of TURBOMOLE's development workflow is provided. Challenges such as communication and outreach, software infrastructure, and funding are highlighted.
489 citations
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TL;DR: The theory and principles of computational phosphorescence are illustrated by highlighting studies of classical examples like molecular nitrogen and oxygen, benzene, naphthalene and their azaderivatives, porphyrins, as well as by reviewing current research on systems like electrophosphorescent transition metal complexes, nucleobases, and amino acids.
Abstract: Phosphorescence is a phenomenon of delayed luminescence that corresponds to the radiative decay of the molecular triplet state. As a general property of molecules, phosphorescence represents a cornerstone problem of chemical physics due to the spin prohibition of the underlying triplet-singlet emission and because its analysis embraces a deep knowledge of electronic molecular structure. Phosphorescence is the simplest physical process which provides an example of spin-forbidden transformation with a characteristic spin selectivity and magnetic field dependence, being the model also for more complicated chemical reactions and for spin catalysis applications. The bridging of the spin prohibition in phosphorescence is commonly analyzed by perturbation theory, which considers the intensity borrowing from spin-allowed electronic transitions. In this review, we highlight the basic theoretical principles and computational aspects for the estimation of various phosphorescence parameters, like intensity, radiative...
362 citations
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TL;DR: A perspective on Kohn-Sham density functional theory (KS-DFT) for electronic structure calculations in chemical physics is presented, which is in widespread use for applications to both molecules and solids.
Abstract: This article presents a perspective on Kohn-Sham density functional theory (KS-DFT) for electronic structure calculations in chemical physics. This theory is in widespread use for applications to both molecules and solids. We pay special attention to several aspects where there are both concerns and progress toward solutions. These include: 1. The treatment of open-shell and inherently multiconfigurational systems (the latter are often called multireference systems and are variously classified as having strong correlation, near-degeneracy correlation, or high static correlation; KS-DFT must treat these systems with broken-symmetry determinants). 2. The treatment of noncovalent interactions. 3. The choice between developing new functionals by parametrization, by theoretical constraints, or by a combination. 4. The ingredients of the exchange-correlation functionals used by KS-DFT, including spin densities, the magnitudes of their gradients, spin-specific kinetic energy densities, nonlocal exchange (Hartree-Fock exchange), nonlocal correlation, and subshell-dependent corrections (DFT+U). 5. The quest for a universal functional, where we summarize some of the success of the latest Minnesota functionals, namely MN15-L and MN15, which were obtained by optimization against diverse databases. 6. Time-dependent density functional theory, which is an extension of DFT to treat time-dependent problems and excited states. The review is a snapshot of a rapidly moving field, and—like Marcel Duchamp—we hope to convey progress in a stimulating way.
261 citations