$R\mathrm{SbTe}$ ($R$ = rare earth) compounds belong to the ZrSiS-type material family, characterized by a square lattice that hosts topological nonsymmorphic Dirac fermions and nodal-line fermions owing to its high crystalline symmetry. In this study, we investigate the structural and electrical properties of the nonmagnetic $R\mathrm{SbTe}$ compounds, LaSbTe and YSbTe, achieving precise control of their band fillings through a crystal growth technique that enables fine-tuning of the Te/Sb ratio. We show that, in the Te-rich region, both compounds crystallize in a high-symmetry tetragonal phase. In this phase, LaSbTe exhibits charge-density-wave order accompanied by a distortion into an orthorhombic lattice, consistent with previous reports. In the Sb-rich region of both compounds, the structure transforms into an orthorhombic phase with space group $P{2}_1{2}_1{2}_1$ (No. 19), featuring a distorted kite-shaped square lattice. This phase exhibits a narrow energy gap, which we attribute to remnants of the band crossings present in the tetragonal phase. We clarify the crystal structures including instabilities arising from high crystalline symmetry, electronic structures, and electrical properties. These findings provide a foundation for future studies of $R\mathrm{SbTe}$ systems, particularly on the interplay between nontrivial band topology and magnetism induced by lanthanide substitution.

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• Charge density waves
• Peierls transition
• Structural properties
• Topological materials