**Figure 2.1.7.1**
Atomic heterogeneity and intensity statistics. The histogram appearing in (*a*) and (*b*) was constructed from values which were recalculated from atomic parameters published for the centrosymmetric structure of C_{6}H_{18}Cl_{2}N_{4}O_{4}Pt (Faggiani *et al.*, 1980). The space group of the crystal is , , *i.e.* all the atoms are located in general positions. (*a*) A comparison of the recalculated distribution of with the ideal centric [equation (2.1.5.11)] and acentric [equation (2.1.5.8)] p.d.f.'s, denoted by and 1, respectively. (*b*) The same recalculated histogram along with the centric correction-factor p.d.f. [equation (2.1.7.5)], truncated after two, three, four and five terms (dashed lines), and with that accurately computed for the correct space-group Fourier p.d.f. [equations (2.1.8.5) and (2.1.8.22)] (solid line). |