where ϵ rel and ϵ abs are suitably chosen threshold parameters. Eq. 35 shows how the TI-ADGA algorithm interprets the value of the TI-ADGA integral. The relative condition compares the relative change in T mn I mn ℓ mn between two iterations and if this change is larger than the relative threshold, ϵ rel , the integration box should be sub-divided. In this way areas of the PES where the density times the energy varies a lot between iterations are subdivided until a convergence is obtained. The TI-ADGA integral can be viewed as a measure for how much a given integration box contributes to the energy and thus if the current value of T mn I mn ℓ mn is very small it can be considered unimportant. This is enforced by the absolute condition, where an integration box is considered converged if both the absolute difference between two iterations and the absolute size of T mn I mn ℓ mn (curr. it.) are smaller than ϵ abs .