Step 2 - Create Configuration

Of course we need a configuration to use as our calculation / analysis target, and which must represent exactly the data file we’re going to read in terms of atom / species ordering, box size etc. The reference system is a 9 mol% isopropanol in water mix, with 3234 molecules - 291 isopropanol followed by 2943 water. The atom coordinates of the xyz species you used in the previous step also reflect the atom ordering within molecules. The periodic box of the reference simulation is cubic with a side length of 48.6080 Å.

So, let’s set up a random mix to mirror all of this:

Configuration ⇨ Create…

Choose both species and press Next

Leave the configuration type as Mixture and press Next

Set the box style to Fixed Geometry and Size and set all three axis lengths A, B, and C to 48.608, then press Next

In the species table change the Population / Ratio of water to 2943 and isopropanol to 291

Set the Multiplier to 1 - this is really important, as otherwise you’ll end up with a huge system with around five million molecules in it!

Press Finish to complete the wizard.

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

With this set-up, the Parameters node is in fact redundant since our density is defined by our imposed box volume and the populations of the species. The CoordinateSets nodes also no longer have any purpose since we will be overwriting the configuration coordinates with our reference data, so if you wanted to you could reduce the number of generated sets in those nodes to 1.

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