Grid density

The wavefunctions of the adsorbed guest are represented on a finite uniform spatial grid. The maximum kinetic energy of the guest, which can be represented in this solutions is therefore limited to $\frac{1}{2m}{\left(\frac{\hbar\pi}{d}\right)}^2$, where $m$ is the mass of the guest, and $d$ is the coarsest grid spacing. For grid spacings of $\approx$ 0.7 bohr, typically used in the following (see Chapter 3 and below) simulations, this condition implies a kinetic energy cutoff of $\sim$850K. As the primarily interested temperatures are $\leq$300K, the impact of the finite basis representation is not severe and it is further reduced by the counter-poise correction, as discussed above.