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- Andersson, Martin, et al.
(författare)
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HFSZEEMAN - A program for computing weak and intermediate field fine and hyperfine structure Zeeman splittings from MCDHF wave functions
- 2008
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Ingår i: Computer Physics Communications. - : Elsevier BV. - 0010-4655 .- 1879-2944. ; 178:2, s. 156-170
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Tidskriftsartikel (refereegranskat)abstract
- Given electronic wave functions generated by the grasp2K relativistic atomic structure package, this program calculates diagonal magnetic dipole A(J) and electric quadrupole B-J hyperfine interaction constants and Lande g(J) factors. In addition the program computes diagonal and off-diagonal reduced hyperfine and Zeeman matrix elements and constructs the total interaction matrix for an atom in an external magnetic field. By diagonalizing the interaction matrix and plotting eigenvalues as functions of the magnetic field, Zeeman splittings of hyperfine levels are obtained. The method is applicable in the weak and intermediate field regions and yields results that are useful when analyzing spectra from e.g. EBIT sources and magnetic stars. The program can also be used in the field free limit to calculate mixing coefficients that determine rates of hyperfine induced transitions. For atoms with zero nuclear spin I the program computes splittings of the fine-structure levels. Program summary Program title: HFSZEEMAN Catalogue identifier: ADZS_v1_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/ADZS-v1-0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 1528 No. of bytes in distributed program, including test data, etc.: 294 664 Distribution format: tar.gz Programming language: Fortran, Matlab Computer: IBM-compatible PC, unix workstation Operating system: Unix, Linux Classification: 11.6 Subprograms used: Cat Id: ADZL_v1_0; Title: grasp2K v1.0; Reference: CPC 177 (2007) 597 Nature of problem: Prediction of weak and intermediate field Zeeman splittings of fine- and hyperfine structure levels using multiconfiguration Dirac-Hartree-Fock wave functions. Solution method: The electronic wave function for a state labeled Gamma JM is expanded in terms of jj-coupled configuration state functions vertical bar Gamma JM > = Sigma(gamma)c(gamma)vertical bar gamma JM >. In this representation the reduced matrix elements used to construct the interaction matrix can be computed as sums over one-particle radial integrals. By diagonalizing the interaction matrix and plotting eigenvalue as functions of the magnetic field, Zeeman splittings of fine- and hyperfine structure levels are obtained. Restrictions: The complexity of the cases that can be handled is entirely determined by the grasp2K package [P. Jonsson, H. Xe, C. Froese Fischer, I.P. Grant, Comput. Phys. Commun. 177 (2007) 597] used for the generation of the electronic wave functions. Running time: CPU time required to execute test cases: a few seconds.
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- Andersson, Martin, et al.
(författare)
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Hyperfine induced interference effects in the 4s4d 3D2–4s4f 3F2,3 transitions in Ga II
- 2006
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Ingår i: Journal of Physics B. - : Bibliopolis, Edizioni di Filosofia e Scienze. - 0953-4075 .- 1361-6455. ; 39:20, s. 4239-4247
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Tidskriftsartikel (refereegranskat)abstract
- We report relativistic multiconfiguration Dirac–Hartree–Fock calculations of transitions between the hyperfine levels of 4s4f 3F2,3 and 4s4d 3D2 in Ga II. The capacity of two newly developed programs connected to the graspVU package for generating synthetic spectra is explored. The obtained theoretical spectra are compared to Fourier transform spectra and good agreement is found. The importance of hyperfine induced interference effects for the 4s4d 3D2–4s4f 3F2 transitions is pointed out, and the gf values for all the hyperfine transitions are given.
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- Beck, P S A, et al.
(författare)
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A ground-validated NDVI dataset for monitoring vegetation dynamics and mapping phenology in Fennoscandia and the Kola peninsula
- 2007
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Ingår i: International Journal of Remote Sensing. - : Informa UK Limited. - 1366-5901 .- 0143-1161. ; 28:19, s. 4311-4330
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Tidskriftsartikel (refereegranskat)abstract
- An NDVI dataset covering Fennoscandia and the Kola peninsula was created for vegetation and climate studies, using Moderate Resolution Imaging Spectroradiometer 16-day maximum value composite data from 2000 to 2005. To create the dataset, ( 1) the influence of the polar night and snow on the NDVI values was removed by replacing NDVI values in winter with a pixel- specific NDVI value representing the NDVI outside the growing season when the pixel is free of snow; and ( 2) yearly NDVI time series were modelled for each pixel using a double logistic function defined by six parameters. Estimates of the onset of spring and the end of autumn were then mapped using the modelled dataset and compared with ground observations of the onset of leafing and the end of leaf fall in birch, respectively. Missing and poor-quality data prevented estimates from being produced for all pixels in the study area. Applying a 5 km x 5 km mean filter increased the number of modelled pixels without decreasing the accuracy of the predictions. The comparison shows good agreement between the modelled and observed dates ( root mean square error = 12 days, n = 108 for spring; root mean square error = 10 days, n = 26, for autumn). Fennoscandia shows a range in the onset of spring of more than 2 months within a single year and locally the onset of spring varies with up to one month between years. The end of autumn varies by one and a half months across the region. While continued validation with ground data is needed, this new dataset facilitates the detailed monitoring of vegetation activity in Fennoscandia and the Kola peninsula.
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- Bieron, Jacek, et al.
(författare)
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Comment on the magnetic dipole hyperfine interaction in the gold atom ground state
- 2008
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Ingår i: Journal of Physics B : Atomic, Molecular and Optical Physics. - : Bibliopolis, Edizioni di Filosofia e Scienze. - 0953-4075 .- 1361-6455. ; 41:11
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Tidskriftsartikel (refereegranskat)abstract
- The multiconfiguration Dirac–Hartree–Fock (MCDHF) model has been employed to calculate the magnetic dipole hyperfine constant A of the 5d106s 2S1/2 ground state of atomic gold. Electron correlation effects contribute more than 20% to the total value of A. We investigated the effects of single, double, and a subset of triple substitutions. The calculations reveal strong cancellations between one-, two- and three-particle correlation effects. It is demonstrated that in the case of the ground state of atomic gold the three-particle effects are comparable in size to the one- and two-particle ones.
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| 8. |
- Bieron, Jacek, et al.
(författare)
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Multiconfiguration Dirac-Hartree-Fock calculations of the electric dipole moment of radium induced by the nuclear Schiff moment
- 2009
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Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics. - : American Physical Society. - 1050-2947 .- 1094-1622. ; 80:1
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Tidskriftsartikel (refereegranskat)abstract
- The multiconfiguration Dirac-Hartree-Fock theory has been employed to calculate the electric dipole moment of the 7s6d 3D2 state of radium induced by the nuclear Schiff moment. The results are dominated by valence and core-valence electron correlation effects. We show that the correlation effects can be evaluated in a converged series of multiconfiguration expansions.
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