## 3 Results
### Visual Estimate Option
The opened window contains six tabs: _Fit, Model, Deviation, Nanoparticle shape, Fixed params_ and _Experiment params_. The chosen tab allows for setting the model type, scaling, and surface parameters. (**b**) Scheme of possible ordering types along one of the basis vectors (\(a_{1}\)) of the NP lattice: long range ordering (LRO), short-range ordering (SRO), and random ordering (RO). The tab _'Model params'_, shown in Figure 6a, enables setting the lattice type that defines the ideal positions of the NPs in a 3D lattice. The ordering is described by three basis vectors \(\mathbf{a}_{1}\)-\(\mathbf{a}_{3}\), whose length and the number of periods along each vector (\(N_{\text{x,y,z}}\)) should be specified. The main features of the basis vectors \(\mathbf{a}_{1}\)-\(\mathbf{a}_{3}\) are illustrated in Figure 6b, where the body centered tetragonal (BCT) lattice is shown. The presented features are the same for other 3D lattices available in the software. The basis vectors \(\mathbf{a}_{1}\) and \(\mathbf{a}_{2}\) are in the plane parallel to the films surface/substrate (\(x\)-\(y\) plane), and they describe the ordering in that plane. The basis vector \(\mathbf{a}_{3}\) describes the vertical ordering of the NPs in a 3D lattice. The multilayer period (denoted by vertical period) is given by the \(z\) component of basis vector \(\mathbf{a}_{3}\). This is well visible in Figure 6c, where a cross-section (\(x\)-\(z\) plane) through the BCT lattice of the NPs is given. The parameters that describe the disorder of the NP positions, with respect to the ideal positions (given by the basis vectors \(\mathbf{a}_{1}\)-\(\mathbf{a}_{3}\)), are given in the tab _'Deviation params'_, shown in Figure 7a. The deviations should be set for each spatial direction (\(x\), \(y\), \(z\)) of each basis vector. Since the basis vectors \(\mathbf{a}_{1}\) and \(\mathbf{a}_{2}\) are in the plane parallel to the substrate surface, they usually have the same disorder parameters (\(\sigma^{1,2}\),\(x\),\(y\)). Therefore, the software uses the same values of disorder for vectors \(\mathbf{a}_{1}\) and \(\mathbf{a}_{2}\) in all models, except for Model 2. For Model 2, each basis vector has its own disorder. The drawback is that if the number of fitting parameters is increased, the fitting process becomes more complex. The proper determination of the deviation parameters is often the most difficult step in the fitting process because they strongly influence the shape and width of the GISAXS map peaks caused by the regularity in the NP positions. Figure 7b shows the scheme of the corresponding NP disorder distributions. As mentioned previously, the parameters \(\sigma^{1,2}\),\(x\),\(y\) describe disorder in the \(x\)-\(y\) plane, while the disorder parameters \(\sigma^{3}\),\(x\) describe the deviations of each new layer of NPs from the ideal position, as illustrated in the right section of Figure 7b. Therefore, these parameters actually define the regularity of the formed 3D lattice, and it is the measure of quality of the self-assembly process in the multilayer deposition preparation method. The vertical (\(z\)) components of disorder \(\sigma^{1,2,3}\),\(x\) often have different properties than the lateral components. Here again it is assumed that the disorder related to basis vectors \(\mathbf{a}_{1}\) and \(\mathbf{a}_{2}\) is the same (\(\sigma^{1}\),\(x\),\(y\)). These parameters describe the vertical fluctuation of each NP in a layer parallel to the surface. The parameter \(\sigma^{3}\),\(x\) describes the vertical deviation of the entire layer, as illustrated on the right in Figure 7c. If the material is produced by the self-assembly process during multilayer deposition, the vertical disorders \(\sigma^{1,2,3}\),\(x\) are usually much smaller than the lateral ones \(\sigma^{1,2,3}\),\(x\),\(y\) because the NP forms within the layers of a multilayer. Some examples are given in [20,21]. Figure 6: (**a**) Tab _Model params_ with the corresponding parameters describing the lattice type and its main parameters.