To apply a Cluster Ratio yourself, it is first essential to understand what you are doing, by reading our publication here.
Your aim is to apply a Cluster Ratio for which the total void size distribution graph does not have a kink at maximum size, as shown in green text in the figure below.
To apply your chosen value, initiate a Build Operation. Then click the Cell properties drop-down menu (highlighted with a yellow square below), and enter your chosen value (red square). Then click the Accept button.