Internal rotor multiple

Troe has described how one can estimate the value of the partition function basic expression for the density of internal states at the dissociation limit, which treats the vibrations in RadiRad ) as harmonic. Multiplicative factors are then estimated to allow, in turn for (i) the anhar-monicity of the vibrations (ii) the energy dependence of the density of vibrational states (iii) an overall rotation factor, which allows for the existence of centrifugal barriers and (iv) an internal rotation factor allowing for the barriers associated with internal rotors. 

Special classes of multiple-pulse sequences were designed by Levitt et al, using the symmetry principles of internal spin Hamiltonians [77,86-88] where an integer number of RF pulse units spans a certain number of rotor cycles. These sequences are classified as CN and RN sequences [77]. 

---