Ca_Si ratio

[dapang201]

Thank you very much for your help, but when I set the calcium-silicon ratio equal to 1.7 and water-silicon ratio equal to 1, the model cannot be generated. Why is this?

[casarziga]

Sometimes it can happen that it cannot generate the structure in accordance with experimental data (which is a polynomial fit: Figure 10 in https://doi.org/10.1016/j.cemconres.2022.106784)

Increase the width factor, which is currently 0.05. This should resolve the problem.

The code automatically places silanol groups to Q1 and Q2b silicate. If you feel like that's not what you would like, simply take the H and put it in to a OH- ion to create a water molecule. This way you can control the SiOH/Si (and CaOH/Ca) ratios by keeping 2H/Si constant.

Generally, the code fails in two cases:

1. either it fails to generate a structure in the given 'width'
2. Or the desired W_Si is set to high since the water molecules are not randomly inserted but have a hard-coded position for the oxygen. When you have many Ca and OH ions in the interlayer, the number of places where it can put an H2O decreases (see SI of the paper, there's a whole table of overlaps)