| Name | Description | Type | Package | Framework |
| IActivityCalculator | Interface for Activity Calculator. | Interface | org.jscience.chemistry.vapor.calculators | JScience |
| IFugacityCalculator | Interface for Fugacity Calculator. | Interface | org.jscience.chemistry.vapor.calculators | JScience |
| MarguleActivityCalculator | Margule's equation implementation for activity calculation. | Class | org.jscience.chemistry.vapor.calculators | JScience |
| PRFugacityCalculator | Peng-Robinson equation implementation for fugacity calculation. | Class | org.jscience.chemistry.vapor.calculators | JScience |
| RKFugacityCalculator | Redlich-Kwong equation implementation for fugacity calculation. | Class | org.jscience.chemistry.vapor.calculators | JScience |
| VanlaarActivityCalculator | VanLaar equation implementation for activity calculation. | Class | org.jscience.chemistry.vapor.calculators | JScience |
| VirialFugacityCalculator | Virial equation implementation for fugacity calculation. | Class | org.jscience.chemistry.vapor.calculators | JScience |