*************************************************************** **** **** **** ESF Programme **** **** **** **** RELATIVISTIC EFFECTS IN HEAVY ELEMENT CHEMISTRY **** **** AND PHYSICS **** **** **** *************************************************************** Newsletter No. 8 (23 August 1994) ______________________________________________________________ Editor: Bernd Hess, hess@rs9.thch.uni-bonn.de Tel. 49-228-732920 FAX 49-228-732251 ______________________________________________________________ The programme 'Relativistic Effects in Heavy-Element Chemistry and Physics' ('REHE') has been initiated by the European Science Foundation in November 1992 and it is expected to run for 5 years, i.e. from 1993 through 1997. The programme is intended to strengthen the in- dicated "field" and to facilitate interactions between European scientists concerned with related topics. The 'Steering Committee' of the programme has at present the following members: E. J. Baerends (Amsterdam) J.P. Desclaux (Grenoble) K. Faegri (Oslo) I.P. Grant (Oxford) B. Hess (Bonn, Vice-Chairman) H. U. Karow (ESF) J. Karwowski (Torun) P. Pyykko (Helsinki, Chairman) K. Schwarz (Vienna) A. Sgamellotti (Perugia). ================================================================================ --- E D I T O R I A L This time, the newsletter has been delayed for a few days because I wanted to include report on the Lanthanide workshop and the announcement of the study centre in December. I am using a new mailer; I apologize for delay and multiply delivered mail and hope the procedure will stabilize after a few tries ... Please send material for the forthcoming newsletter to my attention, hess@rs9.thch.uni-bonn.de The newsletter will be sent out every second month around the 10th day of the month. Contributions should arrive in Bonn until the end of the preceding month. The next newsletter (#9) is scheduled for Beginning of October, 1994. Please send your contributions until End of September 1994. Please send material >by e/mail< that enables us to fill the following topics in forthcoming newsletters ================================================================================ --- F E L L O W S H I P S In the framework of the REHE programme, there is support available for visits of doctoral students and also for senior scientists at institutions in a foreign partner country. This support covers visits lasting 2-4 months ("long-term visits") which will give the holders time to acclimatize to the methods used in the host laboratory as well as short visits ("short-term visits") of only a few days. Please send a short application detailing the project, the names of the scientists involved and the aproximate date and duration of the visit to either Pekka Pyykko or Bernd Hess. Please refer to REHE newsletter #7 for details. ================================================================================ --- R E S E A R C H N E W S AND R E L A T E D I N F O R M A T I O N Summaries of recent research or comments to it (up to 1 page), which are of general interest to the 'REHE' community, may be submitted by any colleague preferrably by E-mail to my attention. [no material for this section in the current newsletter] ================================================================================ --- C O N F E R E N C E N E W S 'Conference News' (in general they should NOT overrun about 1 page) may be provided by organizers or their scientific secretaries. -- For meetings and workshops supported by ESF the submission of such a report is a m u s t . To facilitate my job the reports should be forwarded to my attention via E-mail. Also please send information about conferences that might be of interest for the members of the REHE community. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ [first announcement of study centre on Relativity and Pseudopotentials] ======================================================================= REHE study center on Relativity and Pseudopotentials to be held in Helsinki (Finland) on December 12 - December 16 1994 ======================================================================= The objectives of this study center are to give both a detailed theoretical description of effective core pseudopotential methods and to allow participants to test, hands on, the performance of different approaches (pseudopotentials, model potentials, spin-orbit coupling) with different Quantum Chemistry packages. Morning sessions will be devoted to lectures and afternoon sessions to some pratical applications to selected cases. Additionally , there will be a poster session and a final discussion in which participants will be asked to present their current work or perspectives related to pseudopotentials and/or relativity. It is to be clearly understood that this workshop is directed to researchers already involved in Computational Quantum Chemistry and a basic knowledge of it (including Hartree-Fock approximation, basic configuration interaction technics) will be required. The main clientele for which the study centre is being planned , are the Estern and Central European scientists. Applications which should include a curriculum vitae and a list of publications have to be sent to: Jean-Louis Heully Laboratoire de Physique Quantique Universite Paul Sabatier, 118, route de Narbonne 31062 TOULOUSE CEDEX, FRANCE Tel 61 55 68 33 Fax 61 55 60 65 e-mail heully@pqthp2.ups-tlse.fr} Deadline for applications is October 1 and information on by acceptance will be send to participants on October 1, 1994. Scientific programme (tentative) Monday 12 : Atomic relativistic effects (J.L. Heully) Relativistic effects (P.Pyykko) Tuesday 13 : Pseudopotentials (J.P. Daudey) Spin-Orbit Coupling (C. Marian) Energy adapted pseudopotentials (M. Dolg) Wednesday 14 : Model potentials (U. Wahlgren) Spin-Orbit Coupling (C. Teichteil) Thursday 15 : Pseudopotentials (J.P. Daudey) Model Potentials (U. Wahlgren) Lanthanides and Actinides (M. Dolg) Friday 16 : Beyond frozen-core approximations: Core-valence effects (J.P. Daudey) General Discussion on Specific Scientific projects Lecturers : J.P. Daudey, University of Toulouse, France M. Dolg , Max Planck Institute, Dresden J.L. Heully, University of Toulouse, France Ch. Marian, University of Bonn, Germany U. Wahlgren, University of Stockholm, Sweden P.Pyykko, University of Helsinski, Finland Ch. Teichteil, University of Toulouse, France ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ [report on the ESF workshop on PNC; communicated by A.M. Martensson-Pendrill] P and T-violating properties in atoms and molecules ESF Workshop within the Programme on RELATIVISTIC EFFECTS IN HEAVY ELEMENT CHEMISTRY AND PHYSICS Oxford 7-10 april 1994 Molecular calculations are required to interprete experiments searching for violations of symmetry under parity and time reversal in diatomic molecules. The atomic calculations have seen considerable progress (see e.g. Blundell et al., Theor. Chim. Acta 80, 257 (1991)) and during a few days in April about thirty scientists met in Oxford to discuss possiblities for molecular calculations and problems that may be encountered. Ed Hinds (ehinds@yalevm.ycc.yale.edu) gave an introductory review of experiments (Cho et al., Phys. Rev. Lett. 63, 2559 (1989), Hinds and Sandars, Phys. Rev. A 21, 480 (1980) ) on the diamagnetic molecule TlF (Hinds and Sandars, Phys. Rev. A 21, 480 (1980)), searching primarily for possible >nuclear< electric dipole moments (EDM) and P and T violating interactions of tensor-pseudotensor type (see e.g. Eq (10) in my contribution in >>Methods in Computational Chemistry<<, ed. S. Wilson (Plenum Press, New York, 1992), Vol. 5, p. 99 ) The upper limits obtained from experiments for TlF for these interactions, are among the lowest available. Ed Hinds also presented plans for future experiments on YbF, with the intention of lowering the upper limits for a possible >electron< EDM and a scalar P and T violating interaction (Eq. (9) in the same paper). He also emphasized that the atomic/molecular experiments give information not only competitive with but also complementary to that obtained from limits for the neutron EDM. Several groups had responded to the challenge of these large-scale molecular calculations and many also reported preliminary wavefunctions for TlF. Nevertheless, J\"urgen Hinze predicted that it will be several years before the >ab initio< methods will be able to give better results than those presented by the S:t Petersburg group using Generalized Relativistic Effective Core- Polarization methods (see e.g. Titov et al, Chem. Phys. Lett. 185, 330 (1991)). Since these calculations are difficult, it will be important to have critical tests assuring the reliability of the results obtained (although, as long as only limits are obtained, but no effect observed, results accurate to within a factor of 2, should be adequate). All effects studied get their main contributions from regions within or close to the nucleus. It would the seem worthwhile to calculate measured properties, like magnetic and electric hyperfine structure (hfs), that also test this part of the wavefunction. It was also suggested that the magnetic hfs, which involves a product of the upper and lower component of the relativistic wavefunction would be a sensitive test of the accuracy of the basis set constructed using the kintetic balance approach. Concerning electric hfs, most critical test will of course be performed where the nuclear quadrupole moment is known independently, as compiled by Pyykk\"o and Li, (Nuclear quadrupole moments, Report HUKI 1-92, ISSN 0784-0365 (1992)) Since the effects arise close to or within the nucleus, they are all sensitive mainly to the orbital normalization at the origin and all operators can be related by using the orbital behaviour at small $r$. (O. Sushkov et al., Sov. Phys. JETP 60, 873 (1984)). This can of course be used for testing the calculations, but also to choose the most convenient operator for the evaluation. The question arose on what accuracy is required for the energies in order to obtain sufficient accuracy for P and T violating properties. This probably depends on the methods used in the calculations, since the parts of the wavefunction accounting for the disired effect, in general have very little effect on the energy. However, we note that in investigations of hyperfine structure, using variational wavefunctions, it has been found that nearly all of the correlation energy must be obtained (Carlsson et al. Phys. Rev. A 46, 2420 (1992), Bauschlicher, J. Chem. Phys. 92, 518 (1990)). The electric field at the nucleus (i.e. its average over the nuclear charge distribution) must vanish, since the nucleus remains stationary (Schiff, Phys. Rev. 132, 2194 (1963)) and this should also hold for the calculated wavefunctions according to the "Hellman-Feynman" theorem , although this may not be the case for calculations using limited basis sets. We suggested that model calculations, even non-relativistic, for lighter systems, such as BF, might be useful for examination of the requirements to get this cancellation. In addition to discussions concerning calculations for TlF and YbF, we also had talks on related subjects and we mention here a few: Parity non-conservation (PNC) >without< accompanying T violation has observed and the combined theoretical (Blundell et al., Phys. Rev. D 45, 1602 (1992)) and experimental (Noecker et al., Phys. Rev. Lett. 65, 310 (1988)) accuracy for Cs is sufficient to demand calculations also of small corrections. The results of these experiments are usually expressed in terms of a "weak charge" (Bouchiat and Bouchiat, Phys. Lett. 48B, 111 (1974)). Pat Sandars introduced a new parameter $P_W= \sqrt 2 M_Z^2G_F/ \pi \alpha Q_W$, to describe which is found be largely independent of the weak mixing angle, $\theta _W $ and thus displays more clearly the sensitivity to new physics of atomic PNC experiments (Lynn and Sandars, J. Phys. B 27, 1469 (1994)). For isotope dependent PNC effects, the standard parametrization is, however, found to be a better choice. Jessica James described the dependence of the observed PNC on the nuclear distribution (Pollock et al., Phys. Rev. C 46, 2587 (1992)) in terms of nuclear moments, found to describe accurately a variety of nuclear models. Sergey Porsev presented calculations of quadrupole toroidal moments of positronium. Yulik Khriplovich presented calculations of anapole moments for heavy atoms. A-M Pendrill showed how atomic structure calculations can be used to extract information about nuclear charge and magnetic moment distributions from experimental data, with applications to Tl. We would like to thank the European Science Foundation for support through the program "Relativistic Effects in Heavy Element Chemistry and Physics". Further, we would like to thank Keble College and the Nuclear Physics Institute for providing the setting for a workshop made very enjoyable through the lively discussion by all the participants. Participants The 32 participants included 10 full professors, 13 other senior scientists, 6 post-docs and 3 graduate students. Most of the participants came from Germany, Great Britain and Russia, each represented by 6 scientists, Norway, Sweden and the U.S. were represented by 3 scientists each, and the other participants came from Denmark, Finland, France, Greece and Israel. G\"oteborg and Oxford, July 1994 Jessica James and Ann-Marie M{\aa}rtensson-Pendrill ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ [report on REHE workshop in Helsinki, Finland, 8-9 August 1994, Chairman: M. Dolg (Stuttgart); communicated by M. Dolg] "Electronic Structure Methods for Lanthanides and Actinides" The ESF workshop on Electronic Structure Methods for Lanthanides and Actinides was held 8-9 August in Helsinki as a satellite meeting to the 2nd International Conference on f-Elements. The meeting took place at an institute located on a peninsula 15 km outside of Helsinki. The pleasant surroundings gave opportunity for walks at the seashore, swimming, sauna and informal discussions. The workshop was attended by 28 participants: Brasil 1, Canada 1, Finland 2, France 2, Germany 10, Israel 1, Lesotho 1, Lithuania 1, New Zealand 1, Poland 1, Russia 3, USA 4. 20 participants gave 20 or 40 minutes oral presentations of their work; after each talk 10 minutes were reserved for discussion: G. Malli: Dirac-Hartree-Fock calculations A. J. Mohanty: Dirac-Hartree-Fock calculations on parallel computers U. Kaldor: Relativistic Coupled-Cluster Calculations, application to atoms J. Hinze: numerical methods for atoms and molecules R. M. Pitzer: spin-orbit configuration interaction, application to U@C28 and actinocenes M. Dolg: pseudopotentials for lanthanides, application to CeO and Ce(COT)2 W. Kuechle: pseudopotentials for actinides, application to ThO and Th(COT)2 N. Roesch: INDO for lanthanides and actinides S. V. Vlasov: relativistic density functional band struture calculations P. Fulde: heavy fermion systems M. Richter: 4-component LCAO scheme for solids using a squared Dirac-operator B. Johansson: relativistic effects on solid state properties, LMTO calculations G. Liu: ground state splittings of S-state ions like Gd(3+) 4f7 8S M. F. Reid: correlation effects in f-f transition intensities V. S. Mironov: crystal field calculations for actinide compounds C. Heinemann: experimental and theoretical investigation of lanthanide cations N. Edelstein: optical spectroscopy of f-element compounds G. F. de Sa: extension of the AM1 method to lanthanide complexes Z. Rudzikas: new methods to deal with vector coupling in f-shells P. Pyykkoe: equatorial coordination and bond lengths of uranyl A poster session was held on monday evening to give all participants the opportunity to present their work. It might be interesting to hear that relativistic electronic structure calculations on lanthanide compounds are also performed in chemical industry (D. Suelzle, Schering, Berlin). As seen from the organizer's side the workshop was succesful. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ================================================================================ --- P O S I T I O N S available [no material for this section in the current newsletter] ================================================================================ --- P O S I T I O N S sought [no material for this section in the current newsletter] ================================================================================ --- G O S S I P News about people visiting foreign laboratories, which could eventually faciliate invitations by a nearby lab. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ Dr. J. E. Sienkiewicz is visiting Prof. I. P. Grant in Oxford, from 9 July to 8 October 94, to work on the relativistic CI approach to electron scattering from atoms. ================================================================================ --- ADDRESS LIST The next address list will be provided with newsletter no. 10 In order to join the REHE mailing list, please complete the form below and send it back per e-mail to hess@rs9.thch.uni-bonn.de >>> PLEASE include TEL, FAX, E-MAIL <<< ================================================================= I am interested in receiving the REHE newsletter NAME ----------------------------------------------------------------- ADDRESS ----------------------------------------------------------------- ----------------------------------------------------------------- TEL ----------------------------------------------------------------- FAX ----------------------------------------------------------------- E-MAIL ----------------------------------------------------------------- MAIN RESEARCH INTERESTS ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ End of REHE Newsletter No. 8