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چکیده
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Carbon is one of the most versatile light elements, with a remarkable variety of allotropes that exhibit unique properties. In this work, we introduce a new three-dimensional carbon allotrope, Tessellation-Pottery-C40 (TPC40), predicted using density functional theory (DFT). This structure has orthorhombic symmetry (space group P4mmm, No. 123) and contains 40 atoms per unit cell, featuring a combination of sp2 and sp3 hybridized bonds arranged in four-, five-, and eight-membered rings. To ensure its stability, we first examined the dynamic behavior of TPC40 through phonon dispersion calculations under ambient conditions. We also tested its thermal stability with molecular dynamics simulations in the canonical (NVT) ensemble at both room temperature (300 K) and a higher temperature (800 K). Since mechanical performance is crucial for practical applications of carbon materials, we evaluated the elastic constants, bulk modulus, shear modulus, Young's modulus, and Vickers hardness. Our results highlight the potential of TPC40 as a mechanically robust material. Finally, the electronic properties were analyzed using the HSE06 hybrid functional, showing that TPC40 behaves as a semiconductor with a direct band gap of about 1.35 eV. Altogether, these findings suggest that TPC40 is a promising new carbon phase, combining structural stability, interesting mechanical properties, and semiconducting behavior.
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