  An algebraic model based on Lie-algebraic and discrete symmetry techniques is
applied to the analysis of thermodynamic vibrational properties of molecules.
The local anharmonic effects are described by a Morse-like potential and the
corresponding anharmonic bosons are associated with the SU(2) algebra. A
vibrational high-temperature partition function and the related thermodynamic
functions are derived and studied in terms of the parameters of the model. The
idea of a critical temperature is introduced in relation with the specific
heat. A physical interpretation of a quantum deformation associated with the
model is given.
