Water morphology and porosity under our experimental conditions. Top panels: water ice being deposited at 30 K (left panel) and then being heated to 50 K (middle panel) and water ice being deposited at 50 K (right panel). Each square represents a water molecule and the colour represents the number of the neighbour for each molecule. Blue squares represent water molecules with one neighbour, green with two neighbours, yellow with three neighbours, and red with four neighbours. Bottom panels: size of the pores in the water ice, which is the negative image of the top panel (showing the emptiness in ice). The colour shows the number of grid cells that are empty around the cell (corresponding to 1.6 Å). The figures show deposition at 30 K (left panel), after being heated to 50 K (middle panel) and being deposited at 50 K (right panel).