Professor in Theoretical Physics

Institute of Physics
Lodz University of Technology
Scientific Interests
Development of electronic structure methods based on electron density and re-duced density matrices for molecules. Investigation of spin-states of strongly correlated molecular systems, molecular interactions in out-of-equilibrium and electronically excited complexes.

Education and Employment
M.Sc. in Chemistry, Technical University of Lodz, Poland    1998
Ph.D. in Chemistry, Florida State University, USA    2002
Postdoctoral Researcher, Theoretical Chemistry Department, Vrije Universiteit Amsterdam, The Netherlands (12 months)    2005-2007
Associate Professor, Institute of Physics, Lodz University of Technology,
Poland    2008-2017
Full Professor, Institute of Physics, Lodz University of Technology, Poland    2018-

Awards and Fellowships
Kroto Lecture, Physical Chemistry Section, Department of Chemistry, Florida State University    2018
Award of the International Academy of Quantum Molecular Science (IAQMS)     2015
Marie Curie Intra-European Fellowship    2006
Postdoc Out-going Fellowship KULOMB from the Foundation for Polish Science    2004

Topic Editor in The Journal of Physical Chemistry Letters (ACS)    2021-
Editorial Board Member
Journal of Chemical Theory and Computation (ACS)    2023-present
Scientific Reports (nature publishing group), chemical physics section    2015-present
International Journal of Quantum Chemistry (Wiley)    2017-present

Lecture 20: Katarzyna Pernal


Reduced Functions and Descriptors for Accurate Electronic Structure
Prediction and Understanding Chemical Bonding


Katarzyna Pernal
Institute of Physics, Lodz University of Technology

Obtaining complete information for a many-electron system requires in principle solving the Schrödinger equation and finding the many-electron wavefunction. However, this wavefunction is a complex object that is not only difficult to calculate, but also challenging to use as an interpretive tool. It has been known for a long time that reduced one- and two-electron functions are sufficient to describe the energy of a molecule, electron correlation, and provide insight into the bonding pattern and its changes during a chemical reaction or when the molecular system transitions from the ground state to an excited state.

In the presentation, I will first introduce reduced functions: the electron density, one-electron and two-electron reduced density matrices, and on-top pair density. I will demonstrate their relationship with the full wavefunction and discuss modern computational methods for predicting electronic structure that do not rely on the wavefunction and only use the reduced functions.

In the second part of the presentation, I will introduce bonding and electron correlation descriptors that are constructed in real space from the reduced functions. I will demonstrate how these descriptors allow us to gain physical insight into the dispersion energy in van der Waals complexes [1] and the ionic versus covalent character of states and chemical bonds [2].


[1] P. H. Kowalski, A. Krzeminska, K. Pernal, and E. Pastorczak, J. Phys. Chem. A 2022, 126, 1312.

[2] K. Pernal and O.V. Gritsenko, Faraday Discuss., 2020, 224, 333; M. Hapka, K. Pernal, O. V. Gritsenko, J. Phys. Chem. Lett. 2020, 11, 5883.