Ab initio study of the spin-orbit coupling between the A and b3Πu electronic states of Na2

Accurate ab initio representations of the ground X and the excited A and b3u electronic states of Na2 are computed along with the transition dipole moment between X and A and the spin-orbit coupling term between A and b3u. These data are used to simulate an experiment involving these three states to investigate the effect of spin-orbit coupling on the dynamics of a wave packet oscillating on the A stat

110. PTB-Seminar: Ortsdosisleistungsmessungen ionisierender Strahlung im Bereich der natuerlichen Umgebungsstrahlung Vortraege

Messgeraete zur Messung der Dosis im Bereich der natuerlichen Umgebungstrahlung unterliegen nicht der Eichpflicht. Mehrfach war in der Vergangenheit an die Bundesanstalt die Frage herangetragen worden, welche Massnahmen zur Gewaehrleistung der Messsicherheit in diesem Dosisleistungsbereich, der nicht von der Eichpflicht erfasst wird, getroffen werden sollten. Ausgehend von den eingangs genannten, der Bundesanstalt uebertragenen Aufgabenbereichen sollte dieses Seminar dazu dienen, den Stand des Messwesens auf diesem Gebiet aufzuzeigen, Probleme bei der sachgerechten Durchfuehrung solcher Messungen zu eroertern und moegliche Massnahmen fuer eine Qualitaetssicherung zu diskutieren. Nach einer Uebersicht ueber die messtechnischen Eigenschaften der verfuegbaren Geraete werden Ergebnisse von Vergleichsmessungen vorgestellt und daran anknuepfend Massnahmen zur Qualitaetssicherung bei solchen Messungen diskutiert. Aus jedem Themenbereich wird auch eine anschliessende zusammenfassende Diskussion berichtet. (orig./GL)Measuring instruments for radiation dose measurement in the range of natural ambient radiation are not subject to legal obligations for calibration and the PTB received numerous requests in the past, asking for measures to be taken in order to ensure reliability of measuring results in this range of radiation. This has induced PTB to organise the seminar, intended to present the current status of measuring technology in this field, reveal problems encountered in practical applications, and discuss suitable ction for quality assurance. The papers of the seminar report the measuring performance and capabilities of the available instruments, results of comparative analyses of measurements, and resulting proposed action for quality assurance. Discussions concluding the sessions are also presented in the processdings volume. (orig./CB)Available from TIB Hannover: RN 5178(26) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Explicitly correlated coupled cluster calculations for molecules containing group 11 (Cu, Ag, Au) and 12 (Zn, Cd, Hg) elements: optimized complementary auxiliary basis sets for valence and core–valence basis sets

Compact auxiliary basis sets matched to the standard aug-cc-pVnZ-PP and aug-cc-pwCVnZ-PP orbital basis sets have been developed for the coinage metals (Cu, Ag, Au) and group 12 elements (Zn, Cd, Hg) for use in the resolution of the identity (RI) approximation in explicitly correlated F12 calculations. The CCSD(T)-F12b method has been utilized with these auxiliary basis sets to carry out molecular benchmark calculations on homonuclear coinage metal diatomics (Cu<sub>2</sub>, Ag<sub>2</sub>, Au<sub>2</sub>), as well as mono- (CuF, AgF, AuF) and difluorides (CuF<sub>2</sub>, AgF<sub>2</sub>, AuF<sub>2</sub>). The resulting equilibrium geometries, harmonic vibrational frequencies, and atomization energies demonstrate that CCSD(T)-F12b calculations using double-ζ-quality basis sets produce results comparable in accuracy to conventional CCSD(T) quadruple-ζ calculations, while F12b with triple-ζ-quality sets yields results close to 5-ζ, which is near the conventional complete basis set (CBS) limit estimates. Analogous trends are observed for the group 12 monofluorides (ZnF, CdF, HgF). It is also shown that the effects of correlating the transition metal element (n – 1)s and p electrons are relatively insensitive to the size of the basis set when the F12 method is utilized

Relativistic Small-Core Pseudopotentials for Actinium, Thorium, and Protactinium

Small-core pseudopotentials for actinium, thorium, and protactinium have been energy-adjusted to multiconfiguration Dirac Hartree-Fock reference data based on the Dirac Coulomb Breit Hamiltonian and the Fermi nucleus model. Corresponding optimized valence basis sets of polarized valence quadruple-c quality are presented. Atomic test calculations for the first four ionization potentials show satisfactory results at both the Hartree-Fock and the multireference averaged coupled-pair functional level. Highly correlated Fock-space coupled cluster calculations demonstrate that the new pseudopotentials yield ionization potentials, which are in excellent agreement with corresponding all-electron results and experimental data. The pseudopotentials and basis sets supplement a similar set previously published for uranium

Segmented Contracted Douglas-Kroll-Hess Adapted Basis Sets for Lanthanides

Segmented contracted scalar-relativistic (23s16p12d6f)/[18s12p9d3f] all-electron basis sets for lanthanides La-Lu primarily for use in second-order Douglas-Kroll-Hess density functional calculations are presented. Atomic test calculations at the scalar-relativistic Hartree-Fock level reveal an accurate description of the first to fourth ionization potentials as well as low-energy d-f and d-p excitation energies; i.e., reference data obtained with optimized (34s28p22d16f) even-tempered basis sets are reproduced with mean absolute errors of 0.003 (IP1), 0.013 (IP2), 0.030 (IP3), 0.098 (IP4), 0.070 (d-f), and 0.018 (d-p) eV. Results of molecular test calculations are presented for the lanthanide trihalides LnX(3) (Ln = La-Lu, X = F, Cl, Br, I) at the PBE0 hybrid density functional theory level. Compared to recently published basis sets of identical size, the sets proposed here show substantially smaller errors in the atomic test calculations as well as lower total energies and produce results of similar accuracy in the molecular calibration study