• 3-hydroxypropanal
• astrochemistry
• CCSD(T)
• Cholesky decomposition
• C₃H₆O₂ isomers
• glycidol
• implementation
• minimum energy principle
• rotational spectroscopy

In the first part of this thesis work, a perturbative triple excitations' correction (T) to the Coupled-Cluster singles and doubles (CCSD) energy based on the Cholesky decomposition of the electron-repulsion integrals has been implemented, with the aim of obtaining a less computationally expensive CCSD(T) code.
The second part of this thesis project exploited the collaboration between theory and experiment in the field of rotational spectroscopy applied to astrochemistry. In particular, the C₃H₆O₂ isomer family has been theoretically characterized, from a structural and energetic point of view, by means of a computational protocol based on the Minimum Energy Principle. Then, the rotational spectrum of 3-hydroxypropanal has been theoretically predicted. Two unsuccessful attempts to record its experimental rotational spectrum have been performed, as well. Finally, the experimental rotational spectra of the two most stable conformers of glycidol have been acquired and analyzed in the 65-120 GHz, 146-300 GHz and 440-520 GHz frequency ranges. From these measurements, a new set of spectroscopic parameters (rotational constants, plus quartic, sextic and some octic centrifugal distortion terms) has been obtained for both conformers.