Local vibrational modes of the water dimer - Comparison of theory and experiment

► The vibrational spectrum of the water dimer is analyzed at CCSD(T)/CBS. ► All normal vibrational modes are decomposed in terms of local vibrational modes. ► Normal modes are adiabatically connected to their local vibrational modes. ► The local H-bond stretching frequency at 528 cm−1 reflects the H-bond strength. ► The corresponding normal mode value at 143 cm−1 results from mode-mode coupling.