Texas Tech University
TTU HomeDepartment of Chemistry and Biochemistry Faculty Dr. Hans Lischka

Dr. Hans Lischka

Title:

Research Professor

Education:

Ph.D., University of Vienna, 1968; Postdoctoral Study, University of Karlsruhe, 1972-1973

Research Area:

Theoretical and Computational Chemistry

Office:

Phone:

Fax:

Email:

Chemistry 038

806-834-6769

806-742-1289

Hans.Lischka@ttu.edu

 

Research Group
 

Principal Research Interests

The accurate evaluation of the electronic Schrödinger equation is of fundamental importance in Quantum Chemistry. The program development work of Dr. Lischka concentrates on efficient multireference configuration interaction methods within the framework of the COLUMBUS program system (http://www.univie.ac.at/columbus). This program has unique features for computing electronically excited states and their nonadiabatic interaction. Surface hopping dynamics is performed with the program system NEWTON-X (http://www.univie.ac.at/newtonx).

The photostability of DNA bases. None of the DNA bases show significant fluorescence but deactivate after photoactivation within about one picosecond back to the ground state. The most important decay mechanisms are the NH and interring stretching and ring puckering modes. To identify the actual decay pathways, comprehensive surface hopping dynamics simulations were performed for all DNA/RNA bases. This was the first time that such an extensive photochemical simulation campaign was performed. The results clearly showed that ring puckering modes dominated the dynamics, but also that characteristic differences between purine and pyrimidine bases existed.

The current research work of Dr. Lischka focuses on the photodynamics of DNA. As the figure below shows, several processes can occur in DNA after irradiation with UV light. The most interesting ones are the excitonic interactions in comparison to charge transfer complexes. Photodynamical simulations should show which process is really responsible for the significantly longer life times found experimentally in DNA.

A second photodynamical research project of Dr. Lischka focuses on photovoltaic processes. Main interests are the evolution of excitonic states (see figure below) across kinks in p-conjugated chains such as poly(p-phenylvinylene) and the formation of charge transfer states at boundaries and the separation of charges.

 
 

Representative Publications

Book Chapter