## 4 Conclusions  
Single-crystal CuCr\({}_{1\cdot 1}\)Sn\({}_{0.9}\)S\({}_{2\cdot 3}\)Se\({}_{1\cdot 7}\) and powder samples of CuCr\({}_{2\cdot x}\)Sn\({}_{x}\)S\({}_{2\cdot 3}\)Se\({}_{1\cdot 7}\) and CuCr\({}_{2\cdot x}\)Sn\({}_{x}\)S\({}_{1\cdot 7}\)Se\({}_{2\cdot 3}\) (\(x\) = 0.4, 0.6, and 1.0) were obtained via to using conventional solid-state synthesis. Their crystal structures, as determined by single-crystal XRD, corresponded to normal spinel-type structures. For all the samples, the vibrational analysis and optical properties were in good agreement with the selenospinel phases. The electrical measurements showed a \(p\)-type semiconductor behavior and electrical conductivities lower than those of the seleno- and sulfospinel CuCr\({}_{2}\)\(\chi_{4}\). DFT calculations suggested copper ions are monovalent and hence, diamagnetic. The spin density concentrated in the Cr\({}^{\text{III}}\) ions (S = 3/2), while a more delocalized contribution was associated with S/Se. The theoretical DFT and experimental measurements clearly demonstrated that the conductivity is quite sensitive to the Sn content. However, the non-stoichiometry in the chalcogen, in this case, selenium and sulfur, had a weak influence on the electrical properties.  
The following materials are available online at [[https://www.mdpi.com/article/10.3390/app12031586/s1](https://www.mdpi.com/article/10.3390/app12031586/s1)]([https://www.mdpi.com/article/10.3390/app12031586/s1](https://www.mdpi.com/article/10.3390/app12031586/s1)). Table S1: Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters; Figure S1: Representative powder XRD data for CuCr\({}_{1\cdot 0}\)Sn\({}_{1\cdot 0}\)S\({}_{2\cdot 3}\)Se\({}_{1\cdot 7}\); Figure S2. Vegard's Law; Figure S3: Electrical conductivity against temperature of CuCr\({}_{2\cdot 8}\)Sn\({}_{x}\)S\({}_{2\cdot 3}\)Se\({}_{1\cdot 7}\); Figure S4. Band structures for calculated models. Alpha bands are depicted in black, and beta bands are presented in green; Figure S5: Element and spin-resolved density of states for all calculated systems.  
Conceptualization, A.G. and S.M.; methodology and experiments, P.V.-G., P.B., A.G. and S.M.; writing--original draft preparation, S.M., P.V-G., D.A. and A.G.; electrical measurements, A.G. and P.V-G.; DFT Calculations, D.A. All authors have read and agreed to the final version of the manuscript.  
This research received no external funding.  
Not applicable.  
This work was supported by the Chilean-French International Associated Laboratory for 'Multifunctional Molecules and Materials' (LIAM3-CNRS N\({}^{\circ}\)1027). The authors also thank FONDEQUIP grant EQM140142 for Raman Witec Alpha 300 equipment and the Unidad de Equipamiento Cientifico \"MAINI-UCN\" of the Universidad Catolica del Norte for the generation of diffuse reflectance spectroscopy data through the FONDEQUIP UV-VIS-NIR grant EQM160120.  
Figure 4: Element and spin-resolved density of states for the model CuCrSn\({}_{2}\)Se\({}_{2}\). Remaining systems are presented in Figure S5.  
I ([PERSON]) am also deeply grateful for the scientific collaboration, friendliness, and willingness of Professors [PERSON] and [PERSON] to support me in an unselfish disposition.  
The authors declare no conflict of interest.