5 , where it becomes evident that larger-sized atoms tend to occupy the more stable Na1 site. Furthermore, the authors proposed that this phenomenon leads to a mixed alkali effect, which in turn reduces the ionic conductivity and elevates the activation energy of the (Li/Na) 1+x series when compared to pure sodium analogs. They postulated that lithium diffusion could potentially occur through Na2-Na2 pathways, whereas sodium ions might obstruct the Na1-Na2 pathways. However, a deeper understanding of the atomistic mechanisms underlying these behaviors necessitates further investigations.