Visualization of thermodynamic behaviour of Na+ cation and Cl− anion based on quantum calculation for teaching material

Visualization of thermodynamic behaviour of Na⁺ cation and Cl^- anion was made for teaching-materials creation from the viewpoint of thermodynamics for the student of university or high school level based on a quantum calculation by ab-initio-molecular orbital method. Original Born-Haber cycle including thermodynamic states of Na⁺ cation and Cl^- anion in the dissolution of sodium chloride NaCl are proposed accompanying by construction drawing of molecules from the viewpoint of relative size and stoichiometry, and the intelligible diagrams with changes of entropy and Gibbs function about the dissolution are further introduced for student readily to understand the meaning of thermodynamic changes in the behaviour.