Noura Dawass

3.4. R ESULTS AND DISCUSSION 3 49 (a) ξ (b) L box R > L box /2 Figure 3.1: Schematic representation of finite-size effects in section 3.2. (a) related to the function Q in Eq. (1.26) which represents contributions to KBIs emerging from molecular interactions at the surface of the subvolume V . The only contributions to Q are from molecule pairs with one molecule (1) inside the subvolume V and the other molecule (2) in a surrounding layer of thickness ζ , where ζ is the correlation length of the fluctuations of the RDF (Eq. (2.6) ). Molecules outside this layer ( r 12 > ζ ) do not contribute to Q . (b) related to the finite–size of the simulation box. Shown is a schematic representation of the effect of extending R beyond half the simulation box length, L box /2. The volume of the sphere no longer equals 4 3 π R 3 , and the sphere caps falling outside the box has to be subtracted. Eq. (3.1) and (3.2) provide the area and volume of the truncated spherical subvolume.