As an AI language model, I cannot perform ab initio calculations directly. However, I can provide you with the general procedure to perform ab initio calculations to determine the dipole moment of a H2O molecule at the ground state.1. Choose a suitable level of theory: Select an appropriate quantum mechanical method, such as Hartree-Fock HF or a more advanced method like Mller-Plesset perturbation theory MP2 or density functional theory DFT .2. Select a basis set: Choose an appropriate basis set, such as 6-31G d or cc-pVDZ, which represents the atomic orbitals in the molecule.3. Optimize the geometry: Perform a geometry optimization to find the minimum energy structure of the H2O molecule at the chosen level of theory and basis set. This will provide you with the equilibrium bond lengths and bond angles.4. Calculate the dipole moment: Using the optimized geometry, perform a single-point energy calculation to determine the electronic wavefunction. From this, you can calculate the dipole moment of the molecule.5. Analyze the results: The dipole moment will be given in Debye units D . For the H2O molecule, the dipole moment is approximately 1.85 D, but the exact value will depend on the level of theory and basis set used in the calculation.To perform these calculations, you can use quantum chemistry software packages like Gaussian, ORCA, or Psi4.