Theoretically calculated xyz and log files for hydrogen, carbon monoxide, carbon dioxide, methane, methanol, methyl formate, butene, methyl pentanoate and multiple Pd-dtbpx complexes (dtbpx = 1,2-Bis(di-tert-butylphosphino)xylene) which catalyze the addition of HCOOMe/CO onto butene to form methyl pentanoate. All quantum chemical simulations were performed using the Gaussian16 software. The ground state equilibrium structures and electronic properties were obtained at the density functional (DFT) level of theory utilizing the B3LYP XC functional.The def2-SVP basis set as well as the respective core potentials were applied for all atoms. A subsequent vibrational analysis was carried out for each optimized ground state structure to verify that a minimum on the potential energy (hyper‑)surface (PES) was obtained. All calculations were performed including D3 dispersion correction with Becke-Johnson damping. An analogous computational setup was applied for the optimization of transition states (TSs), while an initial guess in the vicinity of the saddle point was at first obtained via the Nudged Elastic Band (NEB) method as implemented in pysisyphus with xtb. Thereafter, the TSs were obtained in Gaussian16 via the Berny algorithm, followed by a vibrational analysis to verify that a first-order saddle point on the PES was obtained.