This study explores the potential of thorium-doped boron-carbon clathrates to possess beneficial superconducting and mechanical properties as a function of pressure. Using first-principles density functional theory calculations, we assess the dynamic stability, electronic structure, and superconductivity of ${\mathrm{ThB}}_3{\mathrm{C}}_3$ and ${\mathrm{ThB}}_4{\mathrm{C}}_2$, considering the electron-doped superconducting nature of ${\mathrm{ThB}}_3{\mathrm{C}}_3$ and the unexpected metallic behavior of ${\mathrm{ThB}}_4{\mathrm{C}}_2$, despite it being isoelectronic with diamond. ${\mathrm{ThB}}_3{\mathrm{C}}_3$ adopts a cubic Pm$\overline{3}n$ structure, dynamically stable between 70 and 200 GPa, while ${\mathrm{ThB}}_4{\mathrm{C}}_2$ adopts a tetragonal I4/mmm structure, remaining dynamically stable from ambient pressure up to 200 GPa. Convex-hull analysis reveals their thermodynamic stability under high pressure: ${\mathrm{ThB}}_4{\mathrm{C}}_2$ is stable at both 100 and 200 GPa, whereas ${\mathrm{ThB}}_3{\mathrm{C}}_3$ remains metastable across the pressure range considered. Our work is the first to demonstrate that this family of compounds can be metalized via electron doping, as opposed to the hole doping that has been studied to date. ${\mathrm{ThB}}_3{\mathrm{C}}_3$ is predicted to exhibit a superconducting transition temperature $\left(T_c\right)$ of 56 K at 70 GPa, driven by strong electron-phonon coupling (EPC), while ${\mathrm{ThB}}_4{\mathrm{C}}_2$, despite its lower $T_c$ of 0.7 K, is found to maintain superconductivity at ambient pressure. These results emphasize the potential of thorium-doped boron-carbon clathrates as promising candidate materials with tunable superconducting, electronic, and mechanical properties, paving the way for future experimental synthesis and practical applications.

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• Electronic structure
• Pressure effects
• Structural properties
• Superconductivity
• Density functional theory