Phase diagram for one-component system

Is it possible to have a quadruple point in a phase diagram for one component system ... 

Fig. 7.5.1. Generic phase diagram for one-component system the inserts show in various locations of the diagram how the molar Gihhs free energies change when the volume is displaced from its equilihrium value. These various curves are well reproduced hy the Landau functions displayed in Fig. 7.5.2.

In a one-component, or unary, system, only one chemical component is required to describe the phase relationships, for example, iron (Fe), water (H2O) or methane (CH4). There are many one-component systems, including all of the pure elements and compounds. The phases that can exist in a one-component system are limited to vapour, liquid and solid. Phase diagrams for one-component systems are specified in terms of two variables, temperature, normally specified in degrees centigrade,... 

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See also in sourсe #XX -- [ ]

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