Article
Chemistry, Physical
Lucas Lang, Enrico Ravera, Giacomo Parigi, Claudio Luchinat, Frank Neese
Summary: This study elaborated on the derivation of the correct long-distance limit of pseudo-contact nuclear magnetic resonance chemical shifts from rigorous first-principles quantum mechanics, confirming the classical Kurland-McGarvey theory. The study also discussed the application of the point-dipole approximation (PDA) in approximate density functional theory and Hartree-Fock theories, and demonstrated how it is possible to overcome the previous assumption of a crude effective nuclear charge approximation by using the fully relativistic Dirac equation.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Rami Shafei, Dimitrios Maganas, Philipp Jean Strobel, Peter J. Schmidt, Wolfgang Schnick, Frank Neese
Summary: In this study, a computational protocol is developed to predict the absorption and emission spectral shapes of Eu2+-doped phosphors. The energy distribution and band shape of the emission spectrum are found to be related to the nature of the 4f-5d transitions in the absorption process. Simple descriptors are identified that show a strong correlation with the energy position and bandwidth of the experimental emission bands.
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
(2022)
Article
Chemistry, Multidisciplinary
Frank Neese
Summary: The latest version 5.0 of the ORCA quantum chemistry program suite represents a significant improvement in performance, numerical robustness, functionality, and user friendliness.
WILEY INTERDISCIPLINARY REVIEWS-COMPUTATIONAL MOLECULAR SCIENCE
(2022)
Article
Chemistry, Physical
Nicolas O. Foglia, Dimitrios Maganas, Frank Neese
Summary: In this work, a time-dependent density functional theory (TD-DFT) scheme for computing optical spectroscopic properties in the framework of linearly and circularly polarized light is presented. The scheme can calculate absorption, circular dichroism, and magnetic circular dichroism spectra, and takes into account relativistic effects and random orientations of molecules.
JOURNAL OF CHEMICAL PHYSICS
(2022)
Article
Chemistry, Multidisciplinary
Robert Izsak, Christoph Riplinger, Nick S. Blunt, Bernardo de Souza, Nicole Holzmann, Ophelia Crawford, Joan Camps, Frank Neese, Patrick Schopf
Summary: Quantum computers are expected to be useful in simulating strongly correlated chemical systems, but careful selection of orbital spaces is crucial. This study presents a scheme for automatically selecting an active space and combines quantum phase estimation and variational quantum eigensolver algorithms to accurately describe the environment. The protocol outlined here can be applied to chemical systems of any size, including those beyond the capabilities of classical computation.
JOURNAL OF COMPUTATIONAL CHEMISTRY
(2023)
Article
Chemistry, Multidisciplinary
Frank Neese
Summary: This paper describes the SHARK integral generation and digestion engine, which is based on the McMurchie/Davidson approach and utilizes an efficient BLAS algorithm. SHARK can handle various types of basis function integrals and features programming constructs that simplify workflows and avoid code duplication.
JOURNAL OF COMPUTATIONAL CHEMISTRY
(2023)
Article
Chemistry, Physical
Robert Izsak
Summary: A second quantized formulation for evaluating spin-dependent properties in the UHF basis is introduced in this article. The practical usage of this formulation is illustrated using the configuration interaction singles ansatz, and the results are compared to spin-restricted cases of the same ansatz. On a more tentative basis, the notion of quasi-spin-adaptation is also discussed, which ensures that the ansatz becomes spin-adapted as the unrestricted orbitals approach the restricted ones.
Article
Chemistry, Physical
Nick S. Blunt, Joan Camps, Ophelia Crawford, Robert Izsak, Sebastian Leontica, Arjun Mirani, Alexandra E. Moylett, Sam A. Scivier, Christoph Sunderhauf, Patrick Schopf, Jacob M. Taylor, Nicole Holzmann
Summary: Computational chemistry is crucial for the pharmaceutical industry, and quantum computing is a rapidly advancing technology that promises to revolutionize computational capabilities in chemical research. This article explores the potential applications of quantum computation in pharmaceutical problems, specifically in simulating molecules. The authors provide estimates of the quantum computational cost for simulating a protein-drug complex and highlight recent advancements in quantum algorithms that significantly reduce the required resources.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2022)
Article
Chemistry, Physical
Andreas Erbs Hillers-Bendtsen, Dmytro Bykov, Ashleigh Barnes, Dmitry Liakh, Hector H. Corzo, Jeppe Olsen, Poul Jorgensen, Kurt V. Mikkelsen
Summary: We have developed a massively parallel implementation of the CPS(D-3) excitation energy model based on cluster perturbation theory. The extended algorithm efficiently scales with increasing computational resources and allows for low time-to-solution calculations on large molecular systems. The CPS(D-3) excitation energies are shown to be a computationally efficient alternative to those obtained from the coupled-cluster singles and doubles model.
JOURNAL OF CHEMICAL PHYSICS
(2023)
Article
Chemistry, Physical
Robert Izsak, Aleksei V. Ivanov, Nick S. Blunt, Nicole Holzmann, Frank Neese
Summary: In this article, the different measures of electron correlation in wave function theory, density functional theory, and quantum information theory are briefly reviewed. The focus is then placed on a more traditional metric based on dominant weights in the full configuration solution and its behavior regarding the choice of N-electron and one-electron basis. The impact of symmetry is discussed, and the usefulness of distinguishing between determinants, configuration state functions, and configurations as reference functions is emphasized.
JOURNAL OF CHEMICAL THEORY AND COMPUTATION
(2023)
Article
Chemistry, Multidisciplinary
Ingolf Harden, Frank Neese, Giovanni Bistoni
Summary: This study investigates the aggregation process of chiral organocatalysts derived from phosphoric acids using high-level quantum mechanical calculations. The results show that the formation of catalyst dimers is possible and the aggregation process can significantly affect the stereo-controlling factors, reaction kinetics, and selectivity of the transformations.
Article
Chemistry, Multidisciplinary
Ingolf Harden, Frank Neese, Giovanni Bistoni
Summary: The formation of Bronsted acid aggregates in asymmetric organocatalytic reactions has a significant impact on the stereo-controlling factors of the transformations. This study uses high-level quantum mechanical calculations to investigate the influence of catalyst structure and reaction conditions on the spontaneity of the aggregation process, shedding light on its importance.
Article
Chemistry, Physical
M. Atanasov, N. Spiller, F. Neese
Summary: This study uses first principles calculations to simulate magnetic and spectroscopic data, providing an explanation for the stability of a mixed valence binuclear transition metal complex. The study also proposes a new model to interpret the magnetic behavior of the complex.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)
Article
Chemistry, Physical
Andrew M. Teale, Trygve Helgaker, Andreas Savin, Carlo Adamo, Balint Aradi, Alexei Arbuznikov, Paul W. Ayers, Evert Jan Baerends, Vincenzo Barone, Patrizia Calaminici, Eric Cances, Emily A. Carter, Pratim Kumar Chattaraj, Henry Chermette, Ilaria Ciofini, T. Daniel Crawford, Frank De Proft, John F. Dobson, Claudia Draxl, Thomas Frauenheim, Emmanuel Fromager, Patricio Fuentealba, Laura Gagliardi, Giulia Galli, Jiali Gao, Paul Geerlings, Nikitas Gidopoulos, Peter M. W. Gill, Paola Gori-Giorgi, Andreas Gorling, Tim Gould, Stefan Grimme, Oleg Gritsenko, Hans Jorgen Aagaard Jensen, Erin R. Johnson, Robert O. Jones, Martin Kaupp, Andreas M. Koster, Leeor Kronik, Anna Krylov, Simen Kvaal, Andre Laestadius, Mel Levy, Mathieu Lewin, Shubin Liu, Pierre-Francois Loos, Neepa T. Maitra, Frank Neese, John P. Perdew, Katarzyna Pernal, Pascal Pernot, Piotr Piecuch, Elisa Rebolini, Lucia Reining, Pina Romaniello, Adrienn Ruzsinszky, Dennis R. Salahub, Matthias Scheffler, Peter Schwerdtfeger, Viktor N. Staroverov, Jianwei Sun, Erik Tellgren, David J. Tozer, Samuel B. Trickey, Carsten A. Ullrich, Alberto Vela, Giovanni Vignale, Tomasz A. Wesolowski, Xin Xu, Weitao Yang
Summary: This paper provides an informal review and discussion on the history, present status, and future of density-functional theory (DFT) by 70 workers in the field. The format of a roundtable discussion allowed participants to express their views through 302 individual contributions to a preset list of 26 questions. Supported by a bibliography of 777 entries, the paper offers a comprehensive snapshot of DFT in 2022.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2022)