The Thermo usa-button is used after the eigenvalues have been computed. The Thermo usa-button opens the thermodynamics window and uses the eigenvalues to calculate the contribution to entropy, heat capacity and integrated heat capacity(0K to chosen temperature). The thermo window allows the user to choose a temperature, the number of eigenvalues to use, and set a symmetry number. As well as entropy, heat capacity and integrated heat capacity, the window also displays the partition function and the contribution to the partition function of the highest energy eigenvalue used.