scispace - formally typeset
Search or ask a question
Author

Janus J. Eriksen

Bio: Janus J. Eriksen is an academic researcher from University of Bristol. The author has contributed to research in topics: Coupled cluster & Full configuration interaction. The author has an hindex of 15, co-authored 37 publications receiving 1802 citations. Previous affiliations of Janus J. Eriksen include Aarhus University & University of Mainz.

Papers
More filters
Journal ArticleDOI
Kestutis Aidas1, Celestino Angeli2, Keld L. Bak3, Vebjørn Bakken4, Radovan Bast5, Linus Boman6, Ove Christiansen3, Renzo Cimiraglia2, Sonja Coriani7, Pål Dahle8, Erik K. Dalskov, Ulf Ekström4, Thomas Enevoldsen9, Janus J. Eriksen3, Patrick Ettenhuber3, Berta Fernández10, Lara Ferrighi, Heike Fliegl4, Luca Frediani, Kasper Hald11, Asger Halkier, Christof Hättig12, Hanne Heiberg13, Trygve Helgaker4, Alf C. Hennum14, Hinne Hettema15, Eirik Hjertenæs16, Stine Høst3, Ida-Marie Høyvik3, Maria Francesca Iozzi17, Brannislav Jansik18, Hans-Jørgen Aa. Jensen9, Dan Jonsson, Poul Jørgensen3, Johanna Kauczor19, Sheela Kirpekar, Thomas Kjærgaard3, Wim Klopper20, Stefan Knecht21, Rika Kobayashi22, Henrik Koch16, Jacob Kongsted9, Andreas Krapp, Kasper Kristensen3, Andrea Ligabue23, Ola B. Lutnæs24, Juan Ignacio Melo25, Kurt V. Mikkelsen26, Rolf H. Myhre16, Christian Neiss27, Christian B. Nielsen, Patrick Norman19, Jeppe Olsen3, Jógvan Magnus Haugaard Olsen9, Anders Osted, Martin J. Packer9, Filip Pawłowski28, Thomas Bondo Pedersen4, Patricio Federico Provasi29, Simen Reine4, Zilvinas Rinkevicius5, Torgeir A. Ruden, Kenneth Ruud, Vladimir V. Rybkin20, Paweł Sałek, Claire C. M. Samson20, Alfredo Sánchez de Merás30, Trond Saue31, Stephan P. A. Sauer26, Bernd Schimmelpfennig20, Kristian Sneskov11, Arnfinn Hykkerud Steindal, Kristian O. Sylvester-Hvid, Peter R. Taylor32, Andrew M. Teale33, Erik I. Tellgren4, David P. Tew34, Andreas J. Thorvaldsen3, Lea Thøgersen35, Olav Vahtras5, Mark A. Watson36, David J. D. Wilson37, Marcin Ziółkowski38, Hans Ågren5 
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

Journal ArticleDOI
TL;DR: PySCF as mentioned in this paper is a Python-based general-purpose electronic structure platform that supports first-principles simulations of molecules and solids as well as accelerates the development of new methodology and complex computational workflows.
Abstract: PySCF is a Python-based general-purpose electronic structure platform that supports first-principles simulations of molecules and solids as well as accelerates the development of new methodology and complex computational workflows. This paper explains the design and philosophy behind PySCF that enables it to meet these twin objectives. With several case studies, we show how users can easily implement their own methods using PySCF as a development environment. We then summarize the capabilities of PySCF for molecular and solid-state simulations. Finally, we describe the growing ecosystem of projects that use PySCF across the domains of quantum chemistry, materials science, machine learning, and quantum information science.

374 citations

Journal ArticleDOI
TL;DR: In this study, the findings of a blind challenge devoted to determining the frozen-core, full configuration interaction (FCI) ground-state energy of the benzene molecule in a standard correlation-consistent basis set of double-ζ quality are reported.
Abstract: We report on the findings of a blind challenge devoted to determining the frozen-core, full configuration interaction (FCI) ground-state energy of the benzene molecule in a standard correlation-consistent basis set of double-ζ quality. As a broad international endeavor, our suite of wave function-based correlation methods collectively represents a diverse view of the high-accuracy repertoire offered by modern electronic structure theory. In our assessment, the evaluated high-level methods are all found to qualitatively agree on a final correlation energy, with most methods yielding an estimate of the FCI value around -863 mEH. However, we find the root-mean-square deviation of the energies from the studied methods to be considerable (1.3 mEH), which in light of the acclaimed performance of each of the methods for smaller molecular systems clearly displays the challenges faced in extending reliable, near-exact correlation methods to larger systems. While the discrepancies exposed by our study thus emphasize the fact that the current state-of-the-art approaches leave room for improvement, we still expect the present assessment to provide a valuable community resource for benchmark and calibration purposes going forward.

113 citations

Journal ArticleDOI
TL;DR: In this article, the authors investigate the failure of time-dependent density functional theory (TDDFT) with the CAM-B3LYP exchange-correlation (xc) functional coupled to the polarisable embedding (PE) scheme (PE-CAM-B 3LYP) in reproducing the solvatochromic shift of the lowest intense charge-transfer excitation in para-nitroaniline (pNA) in water by comparing with results obtained with the coupled cluster singles and doubles (CCSD) model also coupled to polarizable embedding
Abstract: We investigate the failure of time-dependent density functional theory (TDDFT) with the CAM-B3LYP exchange-correlation (xc) functional coupled to the polarisable embedding (PE) scheme (PE-CAM-B3LYP) in reproducing the solvatochromic shift of the lowest intense charge-transfer excitation in para-nitroaniline (pNA) in water by comparing with results obtained with the coupled cluster singles and doubles (CCSD) model also coupled to the polarisable embedding scheme (PE-CCSD). We determine the amount of charge separation in the ground and excited charge-transfer state with both methods by calculating the electric dipole moments in the gas phase and for 100 solvent configurations. We find that CAM-B3LYP overestimates the amount of charge separation inherent in the ground state and TDDFT/CAM-B3LYP drastically underestimates this amount in the excited charge-transfer state. As the errors in the solvatochromatic shift are found to be inverse proportional to the change in dipole moment upon excitation, we conclude ...

79 citations

Journal ArticleDOI
TL;DR: It is demonstrated how full configuration interaction results in extended basis sets may be obtained to within sub-kJ/mol accuracy by decomposing the energy in terms of many-body expansions in the virtual orbitals of the molecular system at hand.
Abstract: It is demonstrated how full configuration interaction (FCI) results in extended basis sets may be obtained to within sub-kJ/mol accuracy by decomposing the energy in terms of many-body expansions in the virtual orbitals of the molecular system at hand. This extension of the FCI application range lends itself to two unique features of the current approach, namely, that the total energy calculation can be performed entirely within considerably reduced orbital subspaces and may be so by means of embarrassingly parallel programming. Facilitated by a rigorous and methodical screening protocol and further aided by expansion points different from the Hartree–Fock solution, all-electron numerical results are reported for H2O in polarized core-valence basis sets ranging from double-ζ (10 e, 28 o) to quadruple-ζ (10 e, 144 o) quality.

78 citations


Cited by
More filters
01 Feb 1995
TL;DR: In this paper, the unpolarized absorption and circular dichroism spectra of the fundamental vibrational transitions of the chiral molecule, 4-methyl-2-oxetanone, are calculated ab initio using DFT, MP2, and SCF methodologies and a 5S4P2D/3S2P (TZ2P) basis set.
Abstract: : The unpolarized absorption and circular dichroism spectra of the fundamental vibrational transitions of the chiral molecule, 4-methyl-2-oxetanone, are calculated ab initio. Harmonic force fields are obtained using Density Functional Theory (DFT), MP2, and SCF methodologies and a 5S4P2D/3S2P (TZ2P) basis set. DFT calculations use the Local Spin Density Approximation (LSDA), BLYP, and Becke3LYP (B3LYP) density functionals. Mid-IR spectra predicted using LSDA, BLYP, and B3LYP force fields are of significantly different quality, the B3LYP force field yielding spectra in clearly superior, and overall excellent, agreement with experiment. The MP2 force field yields spectra in slightly worse agreement with experiment than the B3LYP force field. The SCF force field yields spectra in poor agreement with experiment.The basis set dependence of B3LYP force fields is also explored: the 6-31G* and TZ2P basis sets give very similar results while the 3-21G basis set yields spectra in substantially worse agreements with experiment. jg

1,652 citations

Journal ArticleDOI
Kestutis Aidas1, Celestino Angeli2, Keld L. Bak3, Vebjørn Bakken4, Radovan Bast5, Linus Boman6, Ove Christiansen3, Renzo Cimiraglia2, Sonja Coriani7, Pål Dahle8, Erik K. Dalskov, Ulf Ekström4, Thomas Enevoldsen9, Janus J. Eriksen3, Patrick Ettenhuber3, Berta Fernández10, Lara Ferrighi, Heike Fliegl4, Luca Frediani, Kasper Hald11, Asger Halkier, Christof Hättig12, Hanne Heiberg13, Trygve Helgaker4, Alf C. Hennum14, Hinne Hettema15, Eirik Hjertenæs16, Stine Høst3, Ida-Marie Høyvik3, Maria Francesca Iozzi17, Brannislav Jansik18, Hans-Jørgen Aa. Jensen9, Dan Jonsson, Poul Jørgensen3, Johanna Kauczor19, Sheela Kirpekar, Thomas Kjærgaard3, Wim Klopper20, Stefan Knecht21, Rika Kobayashi22, Henrik Koch16, Jacob Kongsted9, Andreas Krapp, Kasper Kristensen3, Andrea Ligabue23, Ola B. Lutnæs24, Juan Ignacio Melo25, Kurt V. Mikkelsen26, Rolf H. Myhre16, Christian Neiss27, Christian B. Nielsen, Patrick Norman19, Jeppe Olsen3, Jógvan Magnus Haugaard Olsen9, Anders Osted, Martin J. Packer9, Filip Pawłowski28, Thomas Bondo Pedersen4, Patricio Federico Provasi29, Simen Reine4, Zilvinas Rinkevicius5, Torgeir A. Ruden, Kenneth Ruud, Vladimir V. Rybkin20, Paweł Sałek, Claire C. M. Samson20, Alfredo Sánchez de Merás30, Trond Saue31, Stephan P. A. Sauer26, Bernd Schimmelpfennig20, Kristian Sneskov11, Arnfinn Hykkerud Steindal, Kristian O. Sylvester-Hvid, Peter R. Taylor32, Andrew M. Teale33, Erik I. Tellgren4, David P. Tew34, Andreas J. Thorvaldsen3, Lea Thøgersen35, Olav Vahtras5, Mark A. Watson36, David J. D. Wilson37, Marcin Ziółkowski38, Hans Ågren5 
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

Journal ArticleDOI
TL;DR: The Crystal program as discussed by the authors adopts atom-centered Gaussian-type functions as a basis set, which makes it possible to perform all-electron as well as pseudopotential calculations.
Abstract: The latest release of the Crystal program for solid-state quantum-mechanical ab initio simulations is presented. The program adopts atom-centered Gaussian-type functions as a basis set, which makes it possible to perform all-electron as well as pseudopotential calculations. Systems of any periodicity can be treated at the same level of accuracy (from 0D molecules, clusters and nanocrystals, to 1D polymers, helices, nanorods, and nanotubes, to 2D monolayers and slab models for surfaces, to actual 3D bulk crystals), without any artificial repetition along nonperiodic directions for 0–2D systems. Density functional theory calculations can be performed with a variety of functionals belonging to several classes: local-density (LDA), generalized-gradient (GGA), meta-GGA, global hybrid, range-separated hybrid, and self-consistent system-specific hybrid. In particular, hybrid functionals can be used at a modest computational cost, comparable to that of pure LDA and GGA formulations, because of the efficient implementation of exact nonlocal Fock exchange. Both translational and point-symmetry features are fully exploited at all steps of the calculation, thus drastically reducing the corresponding computational cost. The various properties computed encompass electronic structure (including magnetic spin-polarized open-shell systems, electron density analysis), geometry (including full or constrained optimization, transition-state search), vibrational properties (frequencies, infrared and Raman intensities, phonon density of states), thermal properties (quasi-harmonic approximation), linear and nonlinear optical properties (static and dynamic [hyper]polarizabilities), strain properties (elasticity, piezoelectricity, photoelasticity), electron transport properties (Boltzmann, transport across nanojunctions), as well as X-ray and inelastic neutron spectra. The program is distributed in serial, parallel, and massively parallel versions. In this paper, the original developments that have been devised and implemented in the last 4 years (since the distribution of the previous public version, Crystal14, occurred in December 2013) are described.

1,108 citations

Journal ArticleDOI
TL;DR: This Review describes the recent developments (including some historical aspects) of dispersion corrections with an emphasis on methods that can be employed routinely with reasonable accuracy in large-scale applications.
Abstract: Mean-field electronic structure methods like Hartree–Fock, semilocal density functional approximations, or semiempirical molecular orbital (MO) theories do not account for long-range electron correlation (London dispersion interaction). Inclusion of these effects is mandatory for realistic calculations on large or condensed chemical systems and for various intramolecular phenomena (thermochemistry). This Review describes the recent developments (including some historical aspects) of dispersion corrections with an emphasis on methods that can be employed routinely with reasonable accuracy in large-scale applications. The most prominent correction schemes are classified into three groups: (i) nonlocal, density-based functionals, (ii) semiclassical C6-based, and (iii) one-electron effective potentials. The properties as well as pros and cons of these methods are critically discussed, and typical examples and benchmarks on molecular complexes and crystals are provided. Although there are some areas for furthe...

932 citations