Ab initio methods are computational chemistry methods based on quantum mechanics, which calculate molecular properties from first principles, without any empirical data. The dipole moment of a water molecule calculated using Ab initio methods varies depending on the level of theory and basis set used. However, a common level of theory used for such calculations is the Hartree-Fock HF method with a 6-31G** basis set.Using this method, the calculated dipole moment of a water molecule is approximately 1.85 Debye. The experimentally determined dipole moment of a water molecule is around 1.85 Debye as well. This shows that the Ab initio calculation using the Hartree-Fock method with a 6-31G** basis set provides a reasonably accurate estimation of the dipole moment for a water molecule, as it is in good agreement with the experimental value.