and benchmarked DFT approaches (B3LYP/D95(d,p)/LanL2DZ) against accurate wavefunction based methods (QCISD(T)/DZVP)an approach that has been picked up later on. Due to the limited computational resources, early modeling of (AS-)ALD often had to use size-reduced ligands and model systems and also had to compromise on technical accuracy aspects like basis set size. Nevertheless, in many cases a good agreement to experimental data could be achieved. Modern AS-ALD modelling nearly exclusively models the exact chemical system that is used experimentally. This is important since steric effects by bulky ligands can be a major factor in selectivity.