English
norskBlar i forfatter Artikler, rapporter og annet (kjemi) "Bast, Radovan"
Viser treff 1-9 av 9
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Analytic calculations of hyper-Raman spectra from density functional theory hyperpolarizability gradients
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014) -
Analytic cubic and quartic force fields using density-functional theory
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014) -
Analytic density functional theory calculations of pure vibrational hyperpolarizabilities: The first dipole hyperpolarizability of retinal and related molecules
(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 ... -
Dalton Project: A Python platform for molecular- and electronic-structure simulations of complex systems
(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
(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 ... -
Five-Photon Absorption and Selective Enhancement of Multiphoton Absorption Processes
(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)
(Journal article; Tidsskriftartikkel; Peer reviewed, 2014-11-20) -
Harmonic Infrared and Raman Spectra in Molecular Environments Using the Polarizable Embedding Model
(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
(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) ...
