Dedman College of Humanities and Sciences

SMU research aims to better understand how molecules interact and bond

SMU News
Originally Posted: Nov. 17, 2021

Researchers and students in the Computational and Theoretical Chemistry Group (CATCO) at Southern Methodist University (SMU) are using vibrational spectroscopy to gain new insights into molecules with the help of SMU’s powerful high performance computer. CATCO is led by Elfi Kraka, the Dedman Family Distinguished Professor and chair of the Department of Chemistry at SMU.

The research, funded by a grant from the National Science Foundation (NSF), will result in new understandings of molecular interactions that can then be applied far beyond chemistry, ranging from fine-tuning and designing new materials to understanding and modifying the biological activity in enzymes, with broad applications for health care, combining new vibrational spectroscopy data to be produced at SMU with existing available data that is now useable due to technological advances.

Vibrational spectroscopy uses infrared light to identify and measure characteristics of molecules and is used frequently as an analytical tool in chemical synthesis, biological assays, materials quality control, forensic science, and in the broader health care environment.

SMU recently acquired a state-of-the-art Raman spectrometer under the NSF MRI program. The instrument uses laser light to excite vibrations in a sample, which can reveal a wealth of information ranging from temperature to molecular disorder.

Kraka believes the spectrometer is an excellent counterpart to the group’s computational work on vibrational spectra that is occurring at SMU. She says the instrument’s ultra-low frequency (ULF) filter – which is one of its kind in the Dallas Ft. Worth area – captures vibrations from weak chemical interactions which are not normally accessible on standard instruments.

With the help of SMU’s high performance computer, Kraka and her group are using special computer software developed over the past several years by CATCO to untangle the complex vibrational motions of the atoms in a molecular system, and in that way, decoding how the atoms in a molecule connect and interact. The analysis, commonly referred to as local vibrational mode analysis, helps quantify the strength of chemical bonds and weak chemical interactions.

“Cutting-edge vibrational spectroscopy is continuously broadening our understanding of molecules and their chemical reactions,” Kraka said. “Our team at SMU is on the forefront of extending computational vibrational spectroscopy into periodic systems and solids, a field with a lot of potential, but still in its infancy.”

Several current students and recent graduates of the Ph.D. program in Computational and Theoretical Chemistry at SMU are engaged in the project. The degree program was launched in 2017 and successfully graduated its first cohort this past May.

Since 2009, CATCO members have published over 130 peer-refereed articles, about 70 of which relate to local vibrational mode analysis stretching over a variety of topics from identifying the longest and shortest carbon-carbon bonds to determining individual hydrogen bond strengths in different forms of ice crystals and why warm water freezes faster than cold water.

Kraka credits the CATCO members for systematically developing local vibrational mode analysis over the past decade and says that the actual breakthrough and successful application of local vibrational mode analysis to “real-world” problems would not be possible without access to SMU’s high-performance computing infrastructure.

“Our graduate students and post-docs are learning how supercomputers can be a powerful resource in solving complex chemical problems,” Kraka said. “This experience will be a critical skillset for them as they prepare to enter the STEM workforce and we are extremely fortunate to have access to SMU’s high performance computer.”



CATCO was originally formed in the 1980s at the University of Cologne, Germany, by Dieter Cremer (1944-2017), where the group created its major tool, the quantum chemical program package COLOGNE. In 1990, CATCO moved to Sweden and then relocated to California in 2005. Since 2009, CATCO has been located at SMU, and has been under the leadership of Elfi Kraka since 2007. Today, former members of CATCO are working in eight different countries around the world. Twenty of them are working as assistant, associate, or full professors at well-known universities. So far, more than 75 graduate students and research associates have participated in the CATCO group.

CATCO’s mission is to carry out research in computational chemistry; educate and train graduate and undergraduate students; explain and share its research with the broader public; and develop and apply advanced computer software and machine learning for the calculation of molecules and molecular aggregates in different environments, exploring their properties and chemical reactions.

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