The hypothesis that Si-NS are partially chlorinated is intriguing because halogenated Si-NS have been computationally predicted to exhibit smaller electronic band gaps as compared to fully hydrogenated Si-NS (silicane). For example, chlorination or fluorination of Si-NS were predicted to decrease the electronic band gap by 0.78 or 1.29 eV, respectively. Interestingly, prior density-functional theory (DFT) calculations suggested that the band gap could be tuned between 2.2 and 0.62 eV by controlling the extent of fluorination of polysilane. Similar trends in band gap tunability were predicted for chlorinated germanane, the germanium based analog of silicane. Therefore, the identification of Cl terminated Si sites in Si-NS is highly important for understanding its electronic structure and optoelectronic properties.