Step 2 - Set up a Configuration

Time to create a suitable bulk water configuration for our simulation.

Configuration ⇨ Create…

Choose the water species and press Next

Leave the configuration type as Mixture and press Next

Leave the box style as Fixed Geometry, Undefined Size and press Next

The Density we need is 0.1 atoms/A3 which just happens to be the default, and the standard Multiplier of 1000 is good for us, so press Finish to complete the wizard.

Double-click on the   Configuration   tab’s title and change its name to   Bulk

One thousand water molecules should have a cubic box size of just over 31 Å side length. You will see in the Add node that its Species option is not set to anything, which seems counter-intuitive. Specifying a species here instructs the Add node that $N$ identical copies of the species should be added to the box. In most cases it is preferable to introduce some variety to the geometry of the molecules, and so the Add node can instead reference a CoordinateSets node as the source, and which contains sets of coordinates representing randomised, evolved, or read in (from a file) coordinates for the species.

Before we proceed we’ll tweak the temperature of the configuration.

On the configuration viewer toolbar, click the Temperature button

Set the Temperature to 298 K

Initial, randomised water box containing 1000 molecules


Previous Step Next Step