January 1999: 11 frozen quantum chemists
[Picture]

From left to right: Friedemann Schautz, Yigui Wang, Stephane Pleutin, Gongyi Hong, Martin Albrecht, Ayjamal Abdurahman, Heinz-Jürgen Flad, Yixuan Wang, Michael Dolg, Simon Kalvoda, Peter Reinhardt

Old Pictures of the QC-group

Contributions of the QC group to the MPI-PKS yearbook 1996-1997:
General report for the QC group (German version)
Quantum Monte Carlo subgroup
Solid State subgroup
Pseudopotential subgroup
Lanthanides and Actinides subgroup

Research Activities


The research activities of the quantum chemistry group are in the field of electron correlation effects and relativistic effects for finite systems, i.e., atoms, molecules and clusters, as well as for infinite systems, i.e., polymers and solids. We are involved both in method development and in applications. One of the major areas of interest of the group is to extend and apply the accurate ab initio methods of quantum chemistry to problems of solid state physics. The main cooperations are with the groups of Profs. P. Fulde (MPI-PKS Dresden) and H. Stoll (Universität Stuttgart). Another research topic are quantum chemical investigations of systems with lanthanides and actinides. A brief overview of some projects is given in the following.

  • Electron Correlation Effects:

    Application of the incremental method of H. Stoll (Stuttgart) to evaluate electron correlation contributions to properties of ionic solids like MgO, CaO and NiO (Doll, Dolg) or GdN (Kalvoda, Dolg, Flad). Related studies of covalent systems, e.g., semiconductors, have been carried out by B. Paulus in the group of Prof. Fulde. Recent work in the quantum chemistry group extended the incremental scheme to polymers (Yu, Kalvoda, Dolg). Future research will also address the calculation of excited states at a correlated level (Pleutin).

    Development of efficient pseudopotential Quantum Monte Carlo techniques and programs (GAMBLE) for atoms, molecules and clusters as well as solids (Flad, Schautz). Recent work on atoms included the investigation of spin-orbit splittings of electronic states of heavy elements such as lead Pb. Molecular studies also treated weakly interacting systems, e.g., Van der Waals dimers and small clusters of group 12 elements. The program development for polymers and solids is designed as an alternative to the standard quantum chemistry approaches for electron correlations as applied in the incremental method.

    Rationalization and interpretation of electron correlation effects in first and second row molecules (Yu).

  • Relativistic Effects:

    Development and calibration of energy-consistent relativistic pseudopotentials (Dolg, Küchle).

    Correlated relativistic all-electron calculations for heavy atoms (Shukla).

    Relativistic all-electron density functional calculations for heavy and superheavy atoms and molecules (Liu).

    Spin-Orbit Coupling in pseudopotential Quantum Monte Carlo calculations of atoms and small molecules (Flad).

    Evaluation and interpretation of relativistic effects in chemistry, e.g. contributions to the lanthanide and actinide contraction (Küchle, Dolg).

  • Atoms, Molecules and Clusters:

    Investigations of the properties of lanthanide and actinide compounds, e.g. unusual correlation-induced electronic ground states like in cerocene (Küchle, Liu, Hong, Dolg).

    Calibration studies of ab initio pseudopotential and all-electron density functional schemes for lanthanide and actinide atoms and molecules (Liu, Dolg, Kalvoda).

    Theoretical investigation of small group 12 metal clusters using ab initio pseudopotentials and a coupled-cluster or quantum Monte Carlo correlation treatment. Investigation of the changes in bonding with increasing cluster size (Flad, Wang, Dolg, Schautz).

  • Polymers and Solids:

    Ground state properties of polymers from correlated ab initio calculations (Pleutin, Kalvoda, Abdurahman, Shukla, Dolg).

    Interaction between transition metal atoms with open d-shells in solids (Mödl).

    Development of a quantum chemical program package (WANNIER) for infinite systems, i.e., polymers and solids, using an ab initio embedding scheme and relying on the incremental method for the evaluation of electron correlation effects (Shukla, Schautz).

  • Miscellaneous:

    Analysis of chemical bonding in small metal clusters by means of the electron localization function ELF and its visualization (Wang, Flad, Schautz).

    Analysis of large-scale multi-configuration self-consistent field wavefunctions by expectation values of local operators (local charge and spin, charge and spin fluctuations) (Mödl).

    Michael Dolg


    Michael Dolg, Simon Kalvoda

    [Picture] January 29 1999