Dr. Simone Langner und Dipl.-Ing. (FH) Markus Höhnen
ADDITIVE Soft- und Hardware für Technik und Wissenschaft GmbH, Friedrichsdorf

This presentation does not focus on materials science itself, but rather introduces a software tool designed to help scientists graphically implement and communicate their ideas. To illustrate its capabilities, we use the element water as the subject of demonstration.
The phase diagram of water is one of the most familiar pressure-temperature diagrams, one that we are already confronted with in school. It includes all classical phases - solid, liquid, gas - and also includes anomalies and other phenomena. A prominent example is the triple point, where all three phases of water are in thermodynamic equilibrium. In addition, there are phase boundaries, where two phaeses exist simultaneously.
The aim of the presentation is to demonstrate the creation of a high-quality, visually compelling diagram using the OriginPro software. The underlying data points are publicly available in ASCII format as a basis for creating the diagram.
In summary, the following steps are performed:
•    Importing the basic data using drag and drop
•    Drawing a simple line chart
•    Curves can be smoothed as needed
•    Formatting the linear x-axis and the LOG10 y-axis
•    Gridlines for better readability
•    Grouping the charts and then filling the areas
•    Adding and formatting missing labels
•    Second axis system to display the SI units
•    Reference line at normal pressure 1,013.25 hPa
Key features of the diagram, such as the sublimation, melting, and boiling point curves, are briefly explained. The boiling point curve marks the transition from liquid to gas. At higher pressures and temperatures, this curve terminates at the critical point—a unique condition at 647 K and 221,200 hPa—beyond which the distinction between liquid and vapor disappears due to equalized densities, entering the supercritical phase.
The triple point—at 273.16 K (0.01 °C) and 6.1 hPa—is the intersection of the three boundary curves. At this point, water exists simultaneously as ice, liquid, and vapor in a stable equilibrium, with no net phase transition occurring among them.
This hands-on example demonstrates how OriginPro enables scientists to effectively visualize and annotate complex thermodynamic phenomena using accessible datasets and intuitive workflows.