The Calculation of the Vibrational Energy Spectra of OH Bond in H₂O Molecule

The self-trapping quantum theory has been successfully used to calculate the vibritional energy spectra of multi atom moleciles.When it's used to calculated the stretching vbritional energy spectra in OH bond of H₂O,the results are in better agreement with the experimental values than thoses from the local mode calculation or from the normal mode's.However,the deviation of the calculated values along this line from experiments still increase with the exited state number,due to the original assumption of the constant self-trapping interaction with its adjacent structure.A revised assumption is proposed that the strength of self-trapping interaction between the oscillators varies with the excited states.By means of this new premis,the law by which the vibrational energy varies with the parameters is analyzed qualitatively.According to the data of low states energies,the function relation of the parameters with the ordinal number of the exited sates are fitted out.By means of it,the highly exited spectra of OH bond of H₂O are further calculated.The results obtained are in good agreement with the experiment data.