**Appendix B A Brief Introduction to Statistical Thermodynamics**

Statistical mechanics describes the behavior of macroscopic systems in terms of microscopic properties, i.e., those of particles such as atoms, molecules, ions, etc. That part of statistical mechanics that deals with equilibrium states is called *statistical thermodynamics;* this appendix gives a short introduction whose primary purpose is to provide the working equations of statistical thermodynamics. More detailed discussions are available in many textbooks. Some of these are listed at the end of this appendix. The summary given here is similar to the discussions found in Reed and Gubbins (1973) and Everdell (1975).

**Thermodynamic States and Quantum States of a System**

Thermodynainic ...