A5020239623- Advanced Chemical Physics Studies
- Spectroscopy and Quantum Chemical Studies
- bioluminescence and chemiluminescence research
- Photochemistry and Electron Transfer Studies
- Photoreceptor and optogenetics research
- Machine Learning in Materials Science
- Molecular Junctions and Nanostructures
- X-ray Diffraction in Crystallography
- Advanced NMR Techniques and Applications
- Atmospheric Ozone and Climate
- Computational Drug Discovery Methods
- Crystallography and molecular interactions
- Atomic and Molecular Physics
- Crystallization and Solubility Studies
- Molecular spectroscopy and chirality
- Inorganic Fluorides and Related Compounds
- Radical Photochemical Reactions
- Radioactive element chemistry and processing
- Catalysis and Oxidation Reactions
- Molecular Spectroscopy and Structure
- Mass Spectrometry Techniques and Applications
- Various Chemistry Research Topics
- Solid-state spectroscopy and crystallography
- Chemical Thermodynamics and Molecular Structure
- DNA and Nucleic Acid Chemistry
Uppsala University
2015-2024
Harvard University
2018
University of California, Berkeley
2017
University of Oslo
2010-2014
Lund University
2001-2010
Institute of Theoretical Physics
2003-2010
University of Geneva
2007-2010
Universitat de València
2010
Beijing Normal University
2007-2009
Laboratoire Modélisation et Simulation Multi-Echelle
2009
Abstract Some of the new unique features MOLCAS quantum chemistry package version 7 are presented in this report. In particular, Cholesky decomposition method applied to some chemical methods is described. This approach used both context a straight forward approximation two‐electron integrals and generation so‐called auxiliary basis sets. The article describes how implemented for most known wave functions models: self‐consistent field, density functional theory, 2nd order perturbation...
In this report, we summarize and describe the recent unique updates additions to M olcas quantum chemistry program suite as contained in release version 8. These include natural spin orbitals for studies of magnetic properties, local linear scaling methods Douglas–Kroll–Hess transformation, generalized active space concept MCSCF methods, a combination multiconfigurational wave functions with density functional theory MC‐PDFT method, additional computation diabatization, analytical gradients...
New basis sets of the atomic natural orbital (ANO) type have been developed for main group and rare gas atoms. The ANO's obtained from average density matrix ground lowest excited states atom, positive negative ions, dimer at its equilibrium geometry. Scalar relativistic effects are included through use a Douglas−Kroll Hamiltonian. Multiconfigurational wave functions used with dynamic correlation using second-order perturbation theory (CASSCF/CASPT2). applied in calculations ionization...
New basis sets of the atomic natural orbital (ANO) type have been developed for first, second, and third row transition metal atoms. The ANOs obtained from average density matrix ground lowest excited states atom, positive negative ions, atom in an electric field. Scalar relativistic effects are included through use a Douglas−Kroll−Hess Hamiltonian. Multiconfigurational wave functions used with dynamic correlation using second order perturbation theory (CASSCF/CASPT2). applied calculations...
In this Article we describe the OpenMolcas environment and invite computational chemistry community to collaborate. The open-source project already includes a large number of new developments realized during transition from commercial MOLCAS product platform. paper initially describes technical details software development This is followed by brief presentations many methods, implementations, features program suite. These include novel wave function methods such as stochastic complete active...
MOLCAS/OpenMolcas is an ab initio electronic structure program providing a large set of computational methods from Hartree-Fock and density functional theory to various implementations multiconfigurational theory. This article provides comprehensive overview the main features code, specifically reviewing use code in previously reported chemical applications as well more recent including calculation magnetic properties optimized matrix renormalization group wave functions.
A newly proposed quantum chemical approach for ab initio calculations of electronic spectra molecular systems is applied to the molecules ethene, trans-1,3-butadiene, and trans-trans-1,3,5-hexatriene. The method has aim being accurate better than 0.5 eV excitation energies expected provide structural physical data excited states with good reliability. based on complete active space (CAS) SCF method, which gives a proper description major features in structure state, independent its...
New basis sets of the atomic natural orbital (ANO) type have been developed for lanthanide atoms La-Lu. The ANOs obtained from average density matrix ground and lowest excited states atom, positive ions, atom in an electric field. Scalar relativistic effects are included through use a Douglas-Kroll-Hess Hamiltonian. Multiconfigurational wave functions used with dynamic correlation using second-order perturbation theory (CASSCF/CASPT2). applied calculations ionization energies some excitation...
We propose Cholesky decomposition (CD) of the atomic two-electron integral matrix as a robust and general technique for generating auxiliary basis sets density fitting approximation. The CD (aCD) set is calculated on fly not biased toward particular quantum chemical method. Moreover, accuracy aCD can be controlled with single parameter.
A new method is presented, which makes it possible to partition molecular properties like multipole moments and polarizabilities, into atomic interatomic contributions. The requires a subdivision of the basis set occupied virtual functions for each atom in system. localization procedure organized series orthogonalizations original set, will have as final result localized orthonormal set. demonstrated be stable with various sets, provide physically meaningful properties. Transferability...
The authors propose a new algorithm, “local K” (LK), for fast evaluation of the exchange Fock matrix in case Cholesky decomposition electron repulsion integrals is used. novelty lies fact that rigorous upper bounds to contribution from each occupied orbital are employed. By formulating these inequalities terms localized orbitals, scaling computing reduced quartic quadratic with only negligible prescreening overhead and strict error control. Compared unscreened computational saving...
We report and characterize ground-state excited-state potential energy profiles using a variety of electronic structure methods along loop lying on the branching plane associated with conical intersection (CI) reduced retinal model, penta-2,4-dieniminium cation (PSB3). Whereas performance equation-of-motion coupled-cluster, density functional theory, multireference had been tested excited- paths PSB3 in our earlier work, ability these to correctly describe surface shape CI has not yet...
Abstract The light-induced ultrafast switching between molecular isomers norbornadiene and quadricyclane can reversibly store release a substantial amount of chemical energy. Prior work observed signatures dynamics in both upon ultraviolet excitation but could not follow the electronic relaxation all way back to ground state experimentally. Here we study after exciting (201 nanometres) using time-resolved gas-phase extreme photoelectron spectroscopy combined with non-adiabatic simulations....
Abstract This work presents the quantum chemistry package MOLCAS, with emphasis on its usefulness as a platform for developing new chemical codes, and reader is assumed to be familiar such process. The development of codes time‐consuming job that can dramatically simplified by using libraries standard problems (such calculation integrals), tools surmount computer language operating system limitations. MOLCAS software contains modules variety methods, Hartree–Fock (HF), density functional...
The reduced multiplication scheme of the Rys quadrature is presented. method based on new ways in which can be developed if it implemented together with transfer equation applied to contracted integrals. In parallel improvements are suggested auxiliary function algorithms. two methods have very favorable theoretical floating point operation (FLOP) counts as compared other methods. It noted that only significant difference performance due vectorizability presented order exhibit this, both...
Cholesky decomposition of the atomic two-electron integral matrix has recently been proposed as a procedure for automated generation auxiliary basis sets density fitting approximation [F. Aquilante et al., J. Chem. Phys. 127, 114107 (2007)]. In order to increase computational performance while maintaining accuracy, we propose here reduce number primitive Gaussian functions contracted by means second decomposition. Test calculations show that this is most beneficial in conjunction with highly...
An efficient method to compute analytical energy derivatives for local second-order Møller-Plesset perturbation is presented. Density fitting approximations are employed all 4-index integrals and their derivatives. Using approximations, quadratic scaling with molecular size cubic basis set a given molecule achieved. The density have negligible effect on the accuracy of optimized equilibrium structures or computed differences. can be applied much larger molecules sets than any previous...
ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTTheoretical Study of the Internal Charge Transfer in AminobenzonitrilesLuis Serrano-Andres, Manuela Merchan, Bjoern O. Roos, and Roland LindhCite this: J. Am. Chem. Soc. 1995, 117, 11, 3189–3204Publication Date (Print):March 1, 1995Publication History Published online1 May 2002Published inissue 1 March 1995https://pubs.acs.org/doi/10.1021/ja00116a024https://doi.org/10.1021/ja00116a024research-articleACS PublicationsRequest reuse permissionsArticle...
Abstract Rooted in the very fundamental aspects of many chemical phenomena, and for majority photochemistry, is onset strongly interacting electronic configurations. To describe this challenging regime strong electron correlation, an extraordinary effort has been put forward by a young generation scientists development theories ‘beyond’ standard wave function density functional models. Despite their encouraging results, twenty‐and‐more‐year old approach still stands as gold these problems:...
Using Cholesky decomposition and density fitting to approximate the electron repulsion integrals, an implementation of complete active space self-consistent field (CASSCF) method suitable for large-scale applications is presented. Sample calculations on benzene, diaquo-tetra-mu-acetato-dicopper(II), diuraniumendofullerene demonstrate that approximations allow larger basis sets systems be treated at CASSCF level theory with controllable accuracy. While strict error control inherent property...
Rhodopsin (Rh) and bathorhodopsin (bathoRh) quantum-mechanics/molecular-mechanics models based on ab initio multiconfigurational wave functions are employed to look at the light induced π-bond breaking reconstitution occurring during Rh → bathoRh isomerizations. More specifically, semiclassical trajectory computations used compare excited (S(1)) ground (S(0)) state dynamics characterizing opposite steps of Rh/bathoRh photochromic cycle first 200 fs following photoexcitation. We show that...