(i) Repeated application of the inhibitor as multiple exposure approaches, or even ABCtype ALD cycles where the inhibitor is reapplied in every ALD cycle (Fig. .c) (ii) (Repeated) chemical etching or plasma treatment steps to remove unwanted material on the NGS (also implemented as atomic layer etching, ALE, approaches ) Although these approaches sometimes rely on surface chemistry, they are often not suitable as a target for computational approaches due to the time and length scales involved. An exception is ALE which will not be covered here. Accordingly, computational approaches to post-treatment steps will not be considered further. Blocking is achieved by (b) passivating these reactive surface sites (also called chemical passivation ), (c) preventing precursor and co-reactant adsorption to a reactive site or (d) slowing down the reactivity at the reactive sites favoring the desorption of all adsorbates. As (c) and (d) are caused by steric repulsion, these effects are usually combined under the term steric blocking.