• Analytic calculations of hyper-Raman spectra from density functional theory hyperpolarizability gradients 

      Ringholm, Magnus; Bast, Radovan; Oggioni, Luca; Ekström, Ulf Egil; Ruud, Kenneth (Journal article; Tidsskriftartikkel; Peer reviewed, 2014)
    • Analytic cubic and quartic force fields using density-functional theory 

      Ringholm, Magnus; Jonsson, Dan Johan; Bast, Radovan; Gao, Bin; Thorvaldsen, Andreas johan; Ekstrøm, Ulf; Helgaker, Trygve; Ruud, Kenneth (Journal article; Tidsskriftartikkel; Peer reviewed, 2014)
    • Analytic density functional theory calculations of pure vibrational hyperpolarizabilities: The first dipole hyperpolarizability of retinal and related molecules 

      Gao, Bin; Ringholm, Magnus; Bast, Radovan; Ruud, Kenneth; Thorvaldsen, Andreas johan; Jaszuński, Michał (Journal article; Tidsskriftartikkel; Peer reviewed, 2014-01-09)
      We present a general approach for the analytic calculation of pure vibrational contributions to the molecular (hyper)polarizabilities at the density-functional level of theory. The analytic approach allows us to study large molecules, and we apply the new code to the study of the first dipole hyperpolarizabilities of retinal and related molecules. We investigate the importance of electron ...
    • Assessing impacts of simulated oil spills on the Northeast Arctic cod fishery 

      Carroll, JoLynn; Vikebø, Frode Bendiksen; Howell, Daniel; Broch, OJ; Nepstad, Raymond; Augustine, Starrlight; Skeie, Geir Morten; Bast, Radovan; Juselius, Jonas (Journal article; Tidsskriftartikkel; Peer reviewed, 2017-11-04)
      We simulate oil spills of 1500 and 4500 m3/day lasting 14, 45, and 90 days in the spawning grounds of the commercial fish species, Northeast Arctic cod. Modeling the life history of individual fish eggs and larvae, we predict deviations from the historical pattern of recruitment to the adult population due to toxic oil exposures. Reductions in survival for pelagic stages of cod were 0–10%, up to a ...
    • Dalton Project: A Python platform for molecular- and electronic-structure simulations of complex systems 

      Olsen, Jógvan Magnus Haugaard; Reine, Simen Sommerfelt; Vahtras, Olav; Kjellgren, Erik; Reinholdt, Peter; Dundas, Karen O.H; Li, Xin; Cukras, Janusz; Ringholm, Magnus; Hedegård, Erik Donovan; Di Remigio, Roberto; List, Nanna H.; Faber, Rasmus; Tenorio, Bruno Nunes Cabral; Bast, Radovan; Pedersen, Thomas Bondo; Rinkevicius, Zilvinas; Sauer, Stephan P. A.; Mikkelsen, Kurt V.; Kongsted, Jacob; Coriani, Sonia; Ruud, Kenneth; Helgaker, Trygve; Jensen, Hans Jørgen Aa.; Norman, Patrick (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-06-05)
      The <i>Dalton Project</i> provides a uniform platform access to the underlying full-fledged quantum chemistry codes Dalton and LSDalton as well as the PyFraME package for automatized fragmentation and parameterization of complex molecular environments. The platform is written in Python and defines a means for library communication and interaction. Intermediate data such as integrals are exposed to ...
    • The Dalton quantum chemistry program system 

      Aidas, Kestutis; Angeli, Celestino; Bak, Keld L.; Bakken, Vebjørn; Bast, Radovan; Boman, Linus; Christiansen, Ove; Cimiraglia, Renzo; Coriani, Sonja; Dahle, Pål; Dalskov, Erik K.; Ekström, Ulf Egil; Enevoldsen, Thomas; Eriksen, Janus J.; Ettenhuber, Patrick; Fernández, Berta; Ferrighi, Lara; Fliegl, Heike; Frediani, Luca; Hald, Kasper; Halkier, Asger; Hattig, Christof; Heiberg, Hanne; Helgaker, Trygve; Hennum, Alf Christian; Hettema, Hinne; Hjertenæs, Eirik; Høst, Stine; Høyvik, Ida Marie; Iozzi, Maria Francesca; Jansik, Brannislav; Jensen, Hans-Jørgen Aa.; Jonsson, Dan Johan; Jørgensen, Poul; Kauczor, Johanna; Kirpekar, Sheela; Kjærgaard, Thomas; Klopper, Wim; Knecht, Stefan; Kobayashi, Rika; Koch, Henrik; Kongsted, Jacob; Krapp, Andreas; Kristensen, Kasper; Ligabue, Andrea; Lutnæs, Ola B.; Melo, Juan I.; Mikkelsen, Kurt V.; Myhre, Rolf Heilemann; Neiss, Christian; Nielsen, Christian B.; Norman, Patrick; Olsen, Jeppe; Olsen, Jogvan Magnus H.; Osted, Anders; Packer, Martin J.; Pawlowski, Filip; Pedersen, Thomas Bondo; Provasi, Patricio F.; Reine, Simen Sommerfelt; Rinkevicius, Zilvinas; Ruden, Torgeir A.; Ruud, Kenneth; Rybkin, Vladimir V.; Salek, Pawel; Samson, Claire C. M.; Sanchez de Meras, Alfredo; Saue, Trond; Sauer, Stephan P. A.; Schimmelpfennig, Bernd; Sneskov, Kristian; Steindal, Arnfinn Hykkerud; Sylvester-Hvid, Kristian O.; Taylor, Peter R.; Teale, Andrew M.; Tellgren, Erik; Tew, David P.; Thorvaldsen, Andreas J.; Thøgersen, Lea; Vahtras, Olav; Watson, Mark A.; Wilson, David J. D.; Ziolkowski, Marcin; Ågren, Hans (Journal article; Tidsskriftartikkel; Peer reviewed, 2014-05)
      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. Apart from the total energy, a wide variety of molecular properties may be calculated using these electronic-structure models. Molecular gradients ...
    • The DIRAC code for relativistic molecular calculations 

      Saue, Trond; Bast, Radovan; Gomes, Andre Severo Pereira; Jensen, Hans-Jørgen Aa.; Visscher, Luuk; Aucar, Ignacio Agustín; Di Remigio, Roberto; Dyall, Kenneth G.; Eliav, Ephraim; Fasshauer, Elke; Fleig, Timo; Halbert, Loïc; Hedegård, Erik Donovan; Helmich-Paris, Benjamin; Ilias, Miroslav; Jacob, Christoph R.; Knecht, Stefan; Lærdahl, Jon Kristen; Vidal, Marta L; Nayak, Malaya K.; Olejniczak, Małgorzata; Olsen, Jógvan Magnus Haugaard; Pernpointner, Markus; Senjean, Bruno; Shee, Avijit; Sunaga, Ayaki; van Stralen, Joost N. P. (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-05-26)
      DIRAC is a freely distributed general-purpose program system for one-, two-, and four-component relativistic molecular calculations at the level of Hartree–Fock, Kohn–Sham (including range-separated theory), multiconfigurational self-consistent-field, multireference configuration interaction, electron propagator, and various flavors of coupled cluster theory. At the self-consistent-field level, a ...
    • Five-Photon Absorption and Selective Enhancement of Multiphoton Absorption Processes 

      Friese, Daniel Henrik; Bast, Radovan; Ruud, Kenneth (Journal article; Tidsskriftartikkel; Peer reviewed, 2015-05-12)
      We study one-, two-, three-, four- and five-photon absorption of three centrosymmetric molecules using density functional theory. These calculations are the first ab initio calculations of five-photon absorption. Even- and odd-order absorption processes show different trends in the absorption cross sections. The behaviour of all even-and odd-photon absorption properties shows a semi-quantitative ...
    • Four-Component Relativistic Calculations in Solution with the Polarizable Continuum Model of Solvation: Theory, Implementation and Application to the Group 16 Dihydrides H2X (X= O, S, Se, Te, Po) 

      Di Remigio, Roberto; Bast, Radovan; Frediani, Luca; Saue, Trond (Journal article; Tidsskriftartikkel; Peer reviewed, 2014-11-20)
    • Harmonic Infrared and Raman Spectra in Molecular Environments Using the Polarizable Embedding Model 

      Dundas, Karen Oda Hjorth Minde; Beerepoot, Maarten T. P.; Ringholm, Magnus; Reine, Simen Sommerfelt; Bast, Radovan; List, Nanna Holmgaard; Kongsted, Jacob; Ruud, Kenneth; Olsen, Jógvan Magnus Haugaard (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-05-19)
      We present a fully analytic approach to calculate infrared (IR) and Raman spectra of molecules embedded in complex molecular environments modeled using the fragment-based polarizable embedding (PE) model. We provide the theory for the calculation of analytic second-order geometric derivatives of molecular energies and first-order geometric derivatives of electric dipole moments and dipole–dipole ...
    • Relativistic four-component calculations of Buckingham birefringence using London atomic orbitals 

      Bast, Radovan; Ruud, Kenneth; Rizzo, Antonio; Helgaker, Trygve (Journal article; Tidsskriftartikkel; Peer reviewed, 2011)
      We present the first relativistic study of the electric-field-gradient induced birefringence (Buckingham birefringence), with application to the series of molecules CX2 (X = O, S, Se, Te). A recently developed atomic-orbital-driven scheme for the calculation of time-dependent molecular properties using one-, two- and four-component relativistic wave functions (Bast et al. in Chem Phys 356:177, 2009) ...
    • Simulating crude oil exposure, uptake and effects in North Atlantic Calanus finmarchicus populations 

      Broch, Ole Jacob; Nepstad, Raymond; Ellingsen, Ingrid H.; Bast, Radovan; Skeie, Morten; Carroll, JoLynn (Journal article; Tidsskriftartikkel; Peer reviewed, 2020-10-08)
      A simulation model framework (SYMBIOSES) that includes a 3-dimensional ocean physics and biology model and a model for transport and fate of oil was used to investigate the potential for bioaccumulation and lethal/sublethal effects of oil components in the copepod <i>Calanus finmarchicus</i> in the Lofoten-Vesterålen archipelago of Norway. The oil model is coupled with the biology model by way of a ...
    • Spatial Contributions to Nuclear Magnetic Shieldings 

      Jinger, Rahul Kumar; Fliegl, Heike; Bast, Radovan; Dimitrova, Maria; Lehtola, Susi; Sundholm, Dage (Journal article; Tidsskriftartikkel; Peer reviewed, 2021-02-19)
      We develop a methodology for calculating, analyzing, and visualizing nuclear magnetic shielding densities which are calculated from the current density via the Biot–Savart relation. Atomic contributions to nuclear magnetic shielding constants can be estimated within our framework with a Becke partitioning scheme. The new features have been implemented in the GIMIC program and are applied in this ...