GRASP: A general-purpose relativistic atomic structure program

Dyall, K G; Grant, I P; Johnson, C. T.; Parpia, F. A.; Plummer, Edmund

doi:10.1016/0010-4655(89)90136-7

Cited by 1,483 publications

(991 citation statements)

References 39 publications

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“…Calculations can be done for single levels, but also for portions of a spectrum in the extended optimal level (EOL) scheme, where optimization is on a weighted sum of energies [18]. Using the latter scheme a balanced description of a number of fine-structure states belonging to one or more configurations can be obtained in a single calculation.…”

Section: Computational Proceduresmentioning

confidence: 99%

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Energies and E1, M1, E2, M2 transition rates for states of the 2s22p, 2s2p2, and 2p3 configurations in boron-like ions between N III and Zn XXVI

Rynkun

Jönsson

Gaigalas

et al. 2012

Atomic Data and Nuclear Data Tables

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Energies, E1, M1, E2, M2 transition rates, line strengths, oscillator strengths, and lifetimes from relativistic configuration interaction calculations are reported for the states of the (1s 2 )2s 2 2p, 2s2p 2 , and 2p 3 configurations in all boron-like ions between N III and Zn XXVI. Valence, core-valence, and core-core correlation effects were accounted for through singledouble multireference (SD-MR) expansions to increasing sets of active orbitals.

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Section: Computational Proceduresmentioning

confidence: 99%

“…In the present work, wave functions for all states belonging to a specific configuration were determined simultaneously in an EOL calculation [18]. The configuration expansions were obtained using the active set method [23,24].…”

Section: Generation Of Configuration Expansionsmentioning

confidence: 99%

Energies and E1, M1, E2, M2 transition rates for states of the 2s22p, 2s2p2, and 2p3 configurations in boron-like ions between N III and Zn XXVI

Rynkun

Jönsson

Gaigalas

et al. 2012

Atomic Data and Nuclear Data Tables

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“…In the present paper we used the "optimal level" (OL) energy functional [43] which allows to optimize wavefunctions separately for each individual J value. The (OL) functional provides a better approximation of the true energy for each specific atomic level, at the cost of a very complex energy expression, with many angular integrals beyond the one involved in the average energy.…”

Section: Dirac-fock Calculationsmentioning

confidence: 99%

Are MCDF calculations 101% correct in the super-heavy elements range?

2011

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We explore QED and many-body effects in superheavy elements up to Z = 173 using the multiconfiguration Dirac-Fock method. We study the effect of going beyond the average-level approximation on the determination of the ground state of element 140, and compare with the recent work of Pekka Pyykkö on the periodic table for super heavy elements [1]. We confirm that QED corrections are of the order of 1% on ionization energies. We show that the atomic number at which the 1s shell dives into the negative energy continuum is 173, and is not affected by the approximation employed to evaluate the electron-electron interaction.

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“…All numerical calculations on E119 atom have been carried out with a modified version of GRASP, 34 on which the Gaussian nuclear model 35 was introduced. Atomic relativistic calculations using basis sets were performed with the aid of the DRFATOM software developed by Matsuoka and Watanabe.…”

Section: Methodsmentioning

confidence: 99%

Ab Initio correlated all electron Dirac-Fock calculations for eka-francium fluoride (E119F)

Miranda

Mendes

Gomes

et al. 2012

J. Braz. Chem. Soc.

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Resultados obtidos por cálculos Dirac-Fock correlacionados de 4 componentes para o fluoreto do elemento E119 (Eka-Frâncio) com base estável e precisa, livre de prolapso variacional, são reportados neste trabalho. No nível CCSD(T), a distância de equilíbrio R e , frequência harmônica w e e energia de dissociação D e são 2,432 Å, 354,97 cm -1 e 116,92 kcal mol -1 , respectivamente. Também são reportados base livre de prolapso variacional de 4 componentes para o elemento 119, uma curva analítica de energia potencial precisa e o espectro vibracional a partir dos dados obtidos no nível CCSD(T). Nossos resultados sugerem que a molécula E119F deva ser menos iônica que seus fluoretos alcalinos homólogos mais leves, em contraste com o senso químico comum baseado nas propriedades periódicas -era de se esperar nesta molécula a ligação química mais iônica possível. Também encontramos que a correção do tipo modelo de carga para negligenciar as integrais do tipo SS resulta em erros insignificantes e acelera os cálculos cerca de 3 vezes no nível CCSD(T) e cerca de 4 vezes no nível DFT/B3LYP.Results obtained with correlated 4-component Dirac-Fock calculations for element E119 (ekafrancium) fluoride with stable and accurate basis set (prolapse-free) are reported in this work. At CCSD(T) level, the equilibrium distance R e , harmonic frequency w e and dissociation energy D e are 2.432 Å, 354.97 cm -1 and 116.92 kcal mol -1 , respectively. A 4-component prolapse free basis set for E119, an accurate analytical potential energy curve and vibrational spectra from CCSD(T) data are also reported. Our results suggest that E119F should be less ionic than lighter alkaline fluoride homologues, in contrast to the common chemical belief based on periodic trends -it would be expected in this molecule the most ionic bond possible. We also found that the charge model correction to neglect SS integrals leads to negligible errors and speed up calculations close to three times at CCSD(T) level and close to 4 times at DFT/B3LYP level. Keywords: super heavy elements (SHE), 4-component relativistic molecular calculations, 4-component gaussian basis sets, relativistic effects in chemistry IntroductionThe quest for super heavy nuclei began in 1940's with the synthesis of new elements with an atomic number greater than uranium, and the search for new elements was boosted with the prediction of an "island of stability" 1 for super heavy elements (SHE) with atomic numbers 114,120 and 126. [2][3][4] Some predictions estimate half-lives for isotopes with special combination of proton and neutron numbers as long as 10 8 years, as for 290 Sg 184 . 5,6 Recently, the production of the super heavy elements 112 through 118 using "hot" fusion reactions attained special chemical interest since the reported half-lives are in order of seconds, orders of magnitude longer than those of isotopes produced by "cold" fusion reactions. In addition to short half-lives, the drawback of low production rates also makes chemical experiments expensive, difficult and hard to perfo...

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GRASP: A general-purpose relativistic atomic structure program

Cited by 1,483 publications

References 39 publications

Energies and E1, M1, E2, M2 transition rates for states of the 2s22p, 2s2p2, and 2p3 configurations in boron-like ions between N III and Zn XXVI

Energies and E1, M1, E2, M2 transition rates for states of the 2s22p, 2s2p2, and 2p3 configurations in boron-like ions between N III and Zn XXVI

Are MCDF calculations 101% correct in the super-heavy elements range?

Ab Initio correlated all electron Dirac-Fock calculations for eka-francium fluoride (E119F)

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