II-VI LHs were obtained with a D8 Advance X-ray powder diffractometer (Bruker Corp., Billerica, USA) using Cu Kα radiation. Measurements were performed with a step size of 0.02° (2θ) at a rate of 2 s/step at room temperature. Due to the low scattering angle of the (2 0 0) reflection of ZnSe(dda), powder data shown in Figure for this compound were obtained at room temperature with synchrotron radiation (λ = 0.457901 Å) at beamline 11-BM of the Advanced Photon Source, Argonne National Laboratory. Further experimental details have been described previously. Construction of hypothetical models of ZnSe(ea), ZnSe(ha), ZnSe(oa), ZnSe(da), ZnSe(dda), ZnSe(amch), ZnSe(bza), ZnSe(eea) and ZnSe(boa). Using ZnSe(ba) as a template, all hypothetical models were constructed in Materials Studio 8.0 (Biovia, San Diego, CA). Carbon, hydrogen, and oxygen atoms were either added to or subtracted from the initial ba chains until the chain was transformed to the appropriate ligand. The ZnSe basal plane was not modified in this process. The structure's geometry and unit cell parameters were then optimized using Forcite, a molecular mechanics-based module using the Universal Force Field. Force field parameters used in this work are identical to those described previously. Thermogravimetric analyses (TGA). Thermogravimetric analysis was performed on Discovery TGA 5500 (TA Instruments, New Castle, USA). Samples were loaded into 100 µL platinum pans and heated with a ramp rate of 5 °C from 30 to 500 °C. TRIOS software (TA Instruments) was used for data analysis.