To differentiate molecules based on their structures, infrared (IR) spectroscopy can be utilized. For studying the nine isomers of Tetrachlorobutadiene (TCBD), the process involves several steps. Initially, the molecular structure is created. Following this, simulations are conducted to determine the stable geometry of each molecule. Once a stable configuration is achieved, IR intensity spectra are generated. Finally, the obtained data are compared with existing literature to evaluate the effectiveness of any modifications made during the process. This approach ensures accurate identification and analysis of the TCBD isomers through their IR spectra. First, the molecule was drawn using Molden software. After creating the structure, the 'Write Z-matrix' feature was employed to save a 'Gamess-US' coordinate output file with a '.com' extension. This Z-matrix was used as the input for Psi4 software to perform the geometry optimization step. The geometry optimization in Psi4 was carried out using Density Functional Theory (DFT) methods to determine the most stable molecular configurations, providing a robust foundation for further investigations. All the Z-matrices are presented in 'Appendix A. Z-matrices of the isomers', IR intensity data can be found in 'Appendix B. IR data from the simulation', and all the Python codes are available in 'Appendix C. Python codes' in the Supplementary Data file. Jacob's Ladder, a conceptual framework introduced by John P. Perdew in Density Functional Theory (DFT), serves as a guiding structure for developing and improving exchange-correlation functionals. This metaphorical ladder represents the progressive refinement of functionals, with each rung incorporating increasingly sophisticated physical effects, moving closer to the "heaven of chemical accuracy" in quantum chemistry calculations. Perdew's framework is essential for understanding how DFT functionals have evolved, balancing computational efficiency with accuracy, and has become a standard reference in the field of computational chemistry . The first rung of Jacob's Ladder is the Local Density Approximation (LDA), which relies solely on local electron density to approximate exchange-correlation energy. LDA assumes that the electron density is uniform within small regions of space, which works reasonably well for simple systems like bulk metals or solids but struggles with molecular systems where electron density varies significantly . Despite its limitations, LDA laid the foundation for DFT's widespread application, particularly in solid-state physics. However, its tendency to overestimate binding energies and underestimate band gaps in materials led to the development of more sophisticated methods.