*************************************************************** **** **** **** ESF Programme **** **** **** **** RELATIVISTIC EFFECTS IN HEAVY ELEMENT CHEMISTRY **** **** AND PHYSICS **** **** **** *************************************************************** Newsletter No. 24 (April 28, 1997) ______________________________________________________________ Editor: Bernd Hess, hess@uni-bonn.de Tel. 49-228-732920 FAX 49-228-732551 ______________________________________________________________ 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. Daudey (Toulouse) K. Faegri (Oslo) I.P. Grant (Oxford) B. Hess (Bonn, Vice-Chairman) J. Karwowski (Torun) P. Pyykko (Helsinki, Chairman) K. Schwarz (Vienna) A. Sgamellotti (Perugia) C. Werner (ESF). ================================================================================ --- E D I T O R I A L Please send material for the forthcoming newsletter to my attention, hess@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 (#25) is scheduled for June 1997. Please send material >by e/mail< that enables us to fill the following topics in forthcoming newsletters All REHE newsletters are available on www under URL http://pcgate.thch.uni-bonn.de/tc/hess/esf/nl.html see also the URL of the European Science Foundation http://www.esf.c-strasbourg.fr ================================================================================ --- 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 #16 for details. Please indicate >who wants to go >when >where, >what shall be done and >how much money (in FRF) is required. As a rule, the steering committee members will decide on the applications on occation of ther meetings. Applications for visits that require decision in the interim time between steering committee meetings may still be handled by means of consultation within the steering group. After the journey, a short report about the scientific accomplishments is required. Please send a version by e-mail in a form suitable for publication in a REHE newsletter to hess@uni-bonn.de Should the planned dates of your stay change for any reason, you are requested to notify the Chairman and the Vice-Chairman (preferrably by e-mail) as soon as possible with a copy to the ESF. ================================================================================ --- 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. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ NIST is building an on-line atomic database which is of interest for the REHE community. Here I enclose some information from a letter by Yong-Ki Kim on this database: [communicated by Yong-Ki Kim] March 25, 1997 ... Some part of the database is available on the internet by logging into http://physics.nist.gov, and choosing "physical reference data." For instance, an extensive bibliography for atomic transition probabilities is available, along with fundamental constants and some atomic and molecular spectra. Work is in progress to put an "updated version" of Charlotte Moore's Atomic Energy Levels, though it is not yet available for public view. ... ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ [communicated by Ian P. Grant] Report on a visit by J. Biero\'{n} (Krakow) to I. P. Grant (Oxford) 17.09.96--12.10.96 The work carried out during this visit was in two parts. The first involved a thorough review of the structure of the GRASP multiconfigurational relativistic atomic structure code to decide how best to modify the system the better to study medium to large atoms. Basic features of an efficient parallel angular coefficient package were identified. Major computational savings in the construction of the coulomb and exchange potentials of the multiconfigurational Dirac-Fock model, and of the full energy expression, in a parallel-processing environment are expected from the identification of classes of terms which have a common angular structure. Dr. Biero\'{n} proposes to elaborate these ideas in a major revision of GRASP in Krakow, and we intend to collaborate further on this project. The second part of the work involved a test of the recently developed GRASP92 package by evaluating the effects of relativity and electron correlation on the hyperfine interaction constants of several states of the Sc II ion. A paper is nearly ready for submission to Physical Review A. A similar calculation has also been performed to evaluate the experimentally known quadrupole hyperfine constant of the unstable (64.1 hour) Y$^{90}$ isotope. A paper is in preparation for Zeitschrift f\"{u}r Physik. I. P. Grant, Mathematical Institute, Oxford ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ [communicated by J. P. Daudey] MULTIPARTITIONING PERTURBATION THEORY IN RELATIVISTIC CALCULATIONS ON HEAVY ELEMENT COMPOUNDS A quantitative description of low-lying electronic states of molecules containing heavy transition or coinage metal atoms requires to combine a relativistic treatment with highly accurate account for correlation effects. In most cases when the correlation problem is the main bottleneck, the use of two-step methods which treat the correlation without spin-orbit coupling in non-relativistic symmetries appears to be preferable [1]. We put forward a new approach to correlation relativistic electron structure calculations via constructing a relativistic effective Hamiltonian within a restricted model space spanned by several multiconfigurational wavefunctions. Scalar relativistic effects are incorporated by employing average relativistic core pseudopotentials. The correlation contributions arising from coupling with the outer space are calculated by means of the multi-partitioning many-body perturbation theory (MPPT) [2] restricted to second order. The spin-orbit interactions are taken into account at first order using the spin-orbit pseudopotential technique [3]. This approach is closely related to the CIPSO method [3] employing the conventional (single-partitioning) multireference perturbation theory. The main advantages of using the MPPT technique for correlation treatment consist in a strict size consistency of the results provided that the basis multiconfi- gurational functions are generated as solutions of complete- active-space CI problem (otherwise, at least a good approximative size-consistency and strict "weak" separability are guaranteed) and numerical stability. A high performance of this technique in non-relativistic calculations of light transition and coinage element compounds has yet been demonstrated [4]. Low computational cost is ensured by using the recently developped diagrammatic MPPT formulation. Test calculations on the ground and excited states of the AuH molecule have been performed, using the pseudopotentials from [5] and explicitely correlating 20 outermost electrons. Analogous calculations on (111)H (where (111) stands for eka-gold), AuO, (111)O are to be carried out in the nearest future. This work results from collaboration of A.Z., Ch.Teichteil and L.Maron (Universite P.Sabatier, Toulouse). References [1] M.Dolg, H.Stoll, H.J.Flad, H.Preuss, J.Chem.Phys. 97 (1992) 1662 [2] A.Zaitsevskii, J.P.Malrieu, Chem.Phys.Lett. 250 (1996) 366 [3] Ch.Teichteil, F.Spiegelmann, Chem.Phys. 81 (1983) 283 [4] A.Zaitsevskii, J.P.Malrieu, Theor.Chim.Acta (1997) in press [5] D.Andrae, U.Haussermann, M.Dolg, H.Stoll, H.Preuss, Theor.Chim.Acta 77 (1990) 123 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ [communicated by B. A. Hess] Report on REHE scholarship of Elvira Romera (University of Granada) From September 23, 1996 to November 23, 1996, Elvira Romera from the Departamento de Fisica Moderna of the University of Granada visited Bernd Hess' group at the University of Bonn as a REHE scholar. The project set out to calculate properties of halogen atoms in the ground state (J=3/2) and the first excited state (J=1/2), which result as a fine-structure pair from the same non-relativistic configuration. In previous work [Samzow and Hess, Chem. Phys. Lett. 184 (1991) 491] it had been found that the fine-structure splitting of the bromine atom is very much dependent on the orbital basis used for a configuration-interaction treatment of the correlation. Moreover, the states in question are important from an experimental point of view, because the transition moment for the 3/2 -> 1/2 transition of the iodine atom was experimentally uncertain until very recently [Ha, He, Pochert, Quack, Ranz, Seyfang and Thanopulos, Ber. Bunsenges. Phys. Chem. 99 (1995) 384]. The goal of our work was the calculation of the fine-structure splitting of the ground-state systems of the bromine and iodine atoms and the moment for the transition between the fine-structure levels, in particular the influence of electron correlation on these quantities. We are using the GRASP92 program as well as CASSCF/CI programs based on the Douglas-Kroll-transformed relativistic Hamiltonian. While a final picture has not yet obtained so far, it has been found that, apart from substantial core polarization, a correlation of the semi-core of d symmetry is important for the electronic properties of the states in question. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ [communicated by J. Noffke] Relativistic effects in magnetic interlayer coupling J.~Noffke Institut f\"ur Theoretische Physik, TU Clausthal Leibnizstra{\ss}e 10, D-38678 Clausthal-Zellerfeld, Germany R.~Podloucky Institut f\"ur Physikalische Chemie der Universit\"at Wien, Liechtensteinstra{\ss}e 22a/1/3, A-1090 Wien, Austria and W. Kara{\`s}\\ Academica of Mining and Metallurgy (AGH) Krak\`ow Zaklad Fizyki Cia{\l}a St., 30-059 Krak\`ow, Poland The aim of that project has been the development of a computer program to treat magnetic coupling of layers and surface magnetic anisotropies as key quantities for device application in an accurate and consistent approach. Therefore, the inclusion of all relativistic effects, especially the spin-orbit coupling, has been one of the main points. The ab-initio calculations are based on the density functional theory of Hohenberg, Kohn and Sham [P.~Hohenberg and W.~Kohn, Phys. Rev. {\bf 136}, B 864 (1964), W.~Kohn and L.~J.~Sham, Phys. Rev. {\bf 140}, A 1133 (1965).] which maps the many--body problem for the electrons onto a single--particle description. This consists in Dirac--type one particle equations which have to be solved self--consistently. For that we decided to extend a relativistically generalized version of the Full Potential Linearized Augmented Plane Wave (FLAPW-)method [E.~Wimmer, H.~Krakauer, M.~Weinert and A.~J.~Freeman, Phys. Rev. B {\bf 24}, 864 (1981)] which is one of the most precise ab-initio methods. The first 3-days meeting in December 1994 in Vienna already showed that the calculation of such tiny effects like the magnetic anisotropy energy (of the order of $10^{-4} eV$ for surfaces) does not only require a very accurate method for the determination of the electronic and magnetic structure but should also deliver the relaxation - at least the normal components - of the surface layers. The respective energy contributions may be in the order of magnitude of the effect of spin-orbit coupling. That is, one should do a lot of self-consistent calculations determining the respective total energy, looking for a minimum with respect to the atomic positions. Since those iterations are very time-consuming we decided to first of all develop a method to determine the forces on the atoms and include that in the total program package. The discussion on how to include the spin-orbit coupling lead to the conclusion that only a total revision of the program package of the Vienna Podloucky-group can be the basis of our research activities. The Clausthal FLAPW-code had been developed in a computer environment with only little resources in computer time and memory, also that parts of the package refering to the spin-orbit coupling and the calculation of the magnetic anisotropy [W. Kara\`s, J. Noffke and L. Fritsche, Journal de chimie physique {\bf 86}, 861 (1989)]. The new program should be designed in such a manner that for elements where the spin-orbit coupling leads to neglectable density (and therefore potential) changes it should be possible to simulate different magnetization directions by respective rotations of the wavefunction (especially of the coefficients for the angular momenta expansion inside the atomic spheres). Thus, there would be necessary only one time-consuming determination of the lattice positions consisting of a couple of self-consistent iterations, each with the calculation of the forces on the atoms. Of course, the symmetry of the respective two-dimensional Brillouinzone has to be taken into account, the irrducible part of which depends on the magnetization axis. The wavefunction for the different parts of the surface Brillouinzone is also available by proper rotations of the coefficients of the angular momenta expansion. The anologous method is to transform the respective matrix-elements. An important aspect for the hyperfine field and M\"ossbauer-spectroscopy is the influence of different approximations on the wavefunction in the near of the nucleus which has been studied by Kara\'s (to be published). A one-week stay of R.Podloucky in Clausthal and a short meeting in Vienna have been used to define common interfaces and to decide who should be reponsible for the maintainance of the different parts of the program. As a further outcome of the discussions it seemed to be indispensable to collaborate with St.~Bl\"ugel (KFA J\"ulich), who is well-experienced with calculations for ultra-thin magnetic films. That should guarantee a stable and a trustworthy basis to tackle the hardest problems of a relativistic treatment of magnetically ordered surfaces. We thank REHE for financial support for the meetings, which weren't possible otherwise. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ================================================================================ --- 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. ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ [communicated by K. Schwarz] DFT97 7th International Conference on the Applications of Density Functional Theory in Chemistry and Physics Vienna, September 2-6, 1997 Chairman: K.Schwarz Scope: ====== This four-day conference will bring together scientists interested in DFT, the basic aspects of theory, methodological aspects, program developments and applications in chemistry, biochemistry and physics. The conference will be held at the "TU Wien" and will feature invited talks, posters and panel discussions. It will begin in the evening of Tuesday, Sept.2, with registration and a reception and ends on Saturday, September 6, 1997. International Scientific Committee R.Ahlrichs (Univ.Karlsruhe, D) R.Car (IRMMA Lausanne, CH) P.J.Durham (Daresbury, UK) P.Fantucci (Univ.Milano, Italy) A.Goursot (ENSC Montpellier, F) W.Kohn (Univ.California, Santa Barbara, USA) R.G.Parr (Univ.North Carolina, Chappel Hill, USA D.Salahub (Univ.Montreal, CDN) P.Siegbahn (Univ.Stockholm, Sweden) Local Organizing Committee P.Blaha (TU Vienna) J.Hafner (TU Vienna) P.Herzig (Univ.Vienna) H.Lischka (Univ.Vienna) J.Luitz (TU Vienna) P.Mohn (TU Vienna) E.Nusterer (TU Vienna) K.Schwarz (TU Vienna) Chairman P.Weinberger (TU Vienna) Continouly updated information can be found on the Web page: http://www.tuwien.ac.at/theochem/dft97/ E-mail: ======= dft97@tuwien.ac.at ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ [communicated by Bernd A. Hess] Research Conference on Relativistic Effects on Structure, Dynamics and Spectroscopy Chairman's report on the scientific programme The third Euroconference in the REHE series took place from March 8, 1997 to March 13, 1997 in the Hotel Alixares del Generalife in Granada, Spain. The 71 participants who attended the conference came from from 23 countries. The programme comprised 23 lectures, and 62 posters were displayed and discussed in two poster sessions. In contrast to the earlier conferences (de Haan 1993 and Il Ciocco 1995), no financial support from the Euroconferences programme was available, and the conference was funded entirely by the REHE programme. While the first REHE conference focused on relativistic pseudopotential methods, and the second one on four-component methodology, the present third one was mainly focused on applications of relativistic theory. Nevertheless, relativistic theory was addressed in several lectures, in particular in connection with specific problems in applications. A most interesting issue was risen in the theory of the correlation of relativistic electrons, which was presented by Jacek Karwowski (Torun) and Werner Kutzelnigg (Bochum). Due to the complicated nature of the singularities involved, the situation is not entirely clear, and it appears that a consistent treatment of the two-electron cusp in the relativistic case is still lacking. A second theoretical topic, which was repeatedly addressed by several speakers, is the effective reduction of the number of degrees of freedom by transforming the four-component equations to a lower number of components (two components, or even one in a spin-averaged theory). As Kenneth Dyall (Moffett Field) stressed, the effect of the components which have been integrated out is not neglegted in these theories, since operators resulting from the odd part of the four-component operators are explicitly present in the reduced theories. Andrzej Sadlej (Lund) showed a generalization of the Douglas-Kroll transformation, which is capable of reproducing the Dirac equation values for one-electron atoms to any desired accuracy in the fine-structure constant. Likewise, the Regular Relativistic Approximations presented by Evert Jan Baerends (Amsterdam) are able to describe relativistic effects to any desired order. Thus, the theory of two-component relativistic Hamiltonians seems to be mature, and the long-standing problems with highly singular operators resulting from the truncated Foldy-Wouthuysen transformation are history by now. These methods are particularly useful in the framework of pseudopotentials, and the state of the art in this field was summarized by Christian Teichteil (Toulouse). Walter Ermler (Argonne) contributed a new definition of a large-core pseudopotential, and Paolo Palmieri (Bologna) described in detail the technical aspects of the calculation of spin-orbit coupling matrix elements between correlated wave functions. An interesting aspect of relativistic theory was addressed by Jens Peder Dahl (Lyngby), who lectured on the relativistic Kepler problem, in particular the supersymmetric properties of the Dirac equation. The first session on applications dealt with relativistic effects on nuclear magnetic resonance chemical shifts. The relativistic effects in NMR (which are to a large extent spin-orbit effects) were treated in a quantum-chemical framework by Hiroshi Nakatsuji (Kyoto) and by means of density functional theory by Vladimir Malkin (Bratislava). Without doubt, both methods will be developped further, the introduction of four-component methods and the treatment of electron correlation in a quantum-mechanical framework as reported by Lucas Visscher (Odense) being the most important issues. One of the most stunnning features in the applications of spin-orbit coupling theory, was the importance of relativistic effects in the chemistry of comparatively light elements. Even the reaction of F + H_2 as studied by Hans Joachim Werner (Stuttgart) is to a large extent influenced by spin-orbit effects. David Yarkony (Baltimore) contributed examples in heavier systems. Similar issues were discussed by Boris Minaev (Cherkassy) under the aspect of spin catalysis. The coupling of various spin angular momenta in the theoretical spectroscopy of transition metal compounds was discussed by Christel Marian (Bonn) and compared to experimental results. Obviously, experiments on relativistic systems present an important challenge for the theoretical work. So the lectures by Arne Haaland (Oslo) on the gas-phase structure of molecular compounds of the 5th and 6th row of the periodic table, studied mostly by gas electron diffraction, and the lecture by Lester Andrews (Charlottesville) on matrix-isolation spectroscopy of heavy molecular systems were received very favourably. Peter Schwerdtfeger (Auckland) reviewed recent quantum-chemical calculations on compounds of superheavy elements, which are characterized by the most advanced treatment of electron correlation. Pekka Pyykko (Helsinki) presented a discussion of spin-orbit coupling in chemical bonding, and the turned on on the calculation of quadrupole coupling constants, stressing that the combination of theoretical 'q' and experimental 'e^2 qQ/h' provides international standards for this quantity. The last day featured applications of relativistic theory in the solid state, providing most advanced topics with important impact in the research on new materials. Zoila Barandiaran (Madrid) uses embedded-cluster methods with a spin-free transformed Hamiltonian to define models for crystalline materials, in particular such with transition metal atoms. Hubert Ebert (Munich) lectured about the theoretical treatment of magneto-optical effects in solids using density functional theory, addressing topics important for industrial applications as anisotropic magnetoresistance and the magneto-optical Kerr effect. Finally, a recent relativistic theory of superconductivity was presented by Balasz Gyorffy (Bristol). It can be concluded that chemical applications of relativistic theory are manifold. Chemical notions like the 'heavy atom effect' in NMR and spin recoupling phenomena in chemical reactions find their common theoretical framework in relativistic quantum chemistry. Spin-orbit coupling is a relativistic effect well known from atomic and molecular spectroscopy, and theoretical treatment of these effects is now routinely possible. Applications on magnetic materials and materials featuring transition metals require relativistic theory for proper prediction and description of properties. It was generally felt that the applications of relativistic electronic structure theory of molecules are still at their beginning, and that monitoring the progress in a fourth research conference in about two years is highly desirable. Bernd Hess ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ================================================================================ --- P A P E R S F U N D E D B Y R E H E >>> please send a preprint of papers funded by REHE to Bernd A. He\ss, >>> Institut f\"ur Physikalische und Theoretische Chemie, Universit\"at Bonn, >>> 53115 Bonn, Germany ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ [communicated by Klaus Capelle] K. Capelle and E.K.U. Gross "Spin-density functionals from current-density functional theory and vice versa: A road towards new approximations" Phys. Rev. Lett. 78, p.1872 (1997) K. Capelle, E.K.U. Gross and B.L. Gyorffy "Theory of Dichroism in the Electromagnetic Response of Superconductors" Accepted for publication in Phys. Rev. Lett. 1997 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ --- 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] ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ ================================================================================ --- ADDRESS LIST The REHE address list comprises 193 scientists as of April 28, 1997; the next address list will be provided with newsletter no. 25 This newsletter is mailed to all collegues presently in the REHE mailing list. In order to join the REHE mailing list, please complete the form below and send it back per e-mail to hess@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. 24