Dr. Stefan Knecht
Welcome to the Knecht Group webpage. Here you will find information about our research interests and our latest software developments.

Our research is centred around the density matrix renormalization group (DMRG) approach, which is on the edge of becoming a well-established electronic structure method in chemistry to tackle the exponential scaling problem of solving a full-configuration-interaction type problem. We are particularly interested in developing DMRG-based ab initio wave function methods – possibly combined with density functional theory (DFT) – that allow for the prediction of electronic and magnetic properties such as X-ray, UV-Vis, EPR and NMR spectra of closed and open-shell molecules covering any element of the periodic table of elements.

Other research interests include the (range-separated) ensemble DFT method for the calculation of ground- and excited states (properties) formulated in a time-independent framework as opposed to the widely used time-dependent (TD)-DFT approach, the implementation and development of relativistic multiconfigurational methods, the description of excited-state (reaction) dynamics and the implementation of embedding approaches for (DMRG-based) ab initio wave function methods, aiming towards the study of chemical reactions including solvent and/or protein matrix effects.

Further information about our research and publications can also be found at ResearcherID and ResearchGate.


  • 08-05-2018: Our relativistic DMRG work is featured on the cover of JCTC.

JCTC May 2018 issue

  • 25-04-2018: Personal note: Family grows, today my wife and I welcomed our second son into this world. 🙂
  • 03-04-2018: Roger Kloditz (PhD student under the supervision of my friend and colleague Dr. Michael Patzschke) from the Helmholtz Research Centre Dresden/Rossendorf is visiting our group for five weeks to work with me on various exciting projects within actinide chemistry. Stay tuned for more news in due time.
  • 23-03-2018: Personal note: I received confirmation today from the rector of ETH that I will receive the “Venia Legendi” for Theoretical Chemistry starting (officially) Aug 1st 2018. This marks the end of my “Habilitation”. 🙂
  • 20-03-2018: Our paper on “An efficient relativistic density-matrix renormalization group implementation in a matrix-product formulation” has been accepted for publication in J. Chem. Theory Comput..
    Preprint available on arXiv: 1710.08301
  • 14-02-2018: Software news: A new version of our DMRG program QCMaquis has been released and is available also within OpenMolcas. For further details, check out our QCMaquis homepage.
  • 26-01-2018: I will become a “Notizenautor” for the GDCh-members journal (German chemical society) “Nachrichten aus der Chemie” reporting hot papers in Theoretical Chemistry starting in March 2018.
  • 28-11-2017: Our paper on “Combining extrapolation with ghost interaction correction in range-separated ensemble density functional theory for excited states” has been published in J. Chem. Phys..
    Preprint available on arXiv: 1708.03478
  • 10-10-2017: Our paper on “Generalized Pauli constraints in small atoms” has been submitted to Phys. Rev. Lett. for publication.
    Preprint available on arXiv: 1710.03074
  • 25-09-2017 — 05-10-2017: Sophie Kervazo (PhD student) from U Lille was visiting our group for two weeks to work with me on the thermochemistry of Pu compounds with DMRG-based approaches. Stay tuned for more news in due time.
  • 03-04-2017: I presented our latest research on multiconfigurational quantum chemical approaches for large active orbital spaces at the “Molecular Properties and Computational Spectroscopy” birthday symposium of Antonio Rizzo in Pisa (Italy), April 10-12, 2017.