The research conducted by Gurka and Titus marks a significant contribution to the field of environmental chemistry, with a particular focus on the analysis of TCBDs, or chlorobutadienes. These compounds have garnered attention due to their potential environmental implications. In a study by investigating chlorinated organic compounds, it was revealed that these substances have prolonged environmental persistence, posing heightened health risks . Furthermore, they contribute to ozone layer depletion, exacerbating health concerns for both humans and other organisms inhabiting the Earth. Annika conducted research on various chlorinated organic compounds, highlighting their environmental persistence and carcinogenic properties. Particularly alarming was the finding that these compounds could be highly toxic to developing embryos, fetuses, and infants . Gurka and Titus set out to explore the presence and characteristics of nine chlorinated butadiene compounds found in environmental samples. Employing a meticulous blend of experimental techniques such as gas chromatography/mass spectrometry (GC/MS) and Fourier transform infrared spectrometry (FT-IR), alongside computational modeling using ab initio Hartree-Fock (HF) theory, they aimed to shed light on the nature of these compounds. By leveraging HF theory, a foundational quantum mechanical approach, they were able to predict the vibrational frequencies and intensities of chlorobutadiene isomers, aiding in their identification and structural understanding. Through their combined experimental and computational approach, Gurka and Titus provided significant insights into the composition of environmental samples, enriching my understanding of chlorobutadiene contamination sources and pathways. Hartree-Fock (HF) theory has played a crucial role in the development of quantum chemistry, offering valuable insights into molecular structures, bonding, and electronic properties. However, despite its success, HF theory is limited by its treatment of electron correlation, which only accounts for mean-field interactions between electrons. This approximation becomes problematic in systems where strong electron correlation effects dominate, such as transition metal complexes, strongly correlated materials, and certain types of chemical reactions, leading to inaccurate predictions of molecular properties. To address these shortcomings, more advanced computational techniques have been developed that extend beyond the limitations of HF.