Within the semiclassical Boltzmann transport theory in the constant relaxation-time approximation, we perform an ab initio study of the transport properties of selected systems, including crystalline solids and nanostructures. A local (Gaussian) basis set is adopted and exploited to analytically evaluate band velocities as well as to access full and range-separated hybrid functionals (such as B3LYP, PBE0, or HSE06) at a moderate computational cost. As a consequence of the analytical derivative, our approach is computationally efficient and does not suffer from problems related to band crossings. We investigate and compare the performance of a variety of hybrid functionals in evaluating Boltzmann conductivity. Demonstrative examples include silicon and aluminum bulk crystals as well as two thermoelectric materials (CoSb₃, Bi₂Te₃). We observe that hybrid functionals other than providing more realistic bandgaps—as expected—lead to larger bandwidths and hence allow for a better estimate of transport properties, also in metallic systems. As a nanostructure prototype, we also investigate conductivity in boron-nitride (BN) substituted graphene, in which nanoribbons (nanoroads) alternate with BN ones.

中文翻译：

---

从完全和范围分离的混合官能团算起固体的从头算起的电子传输和热电性质

在常数松弛时间近似的半经典玻尔兹曼输运理论中，我们执行从头算研究所选系统的传输特性，包括晶体固体和纳米结构。采用本地（高斯）基集并以适度的计算成本来分析评估频带速度以及访问完整的和范围分隔的混合功能（例如B3LYP，PBE0或HSE06）。作为分析导数的结果，我们的方法计算效率高，并且不会遇到与频带穿越有关的问题。我们调查和比较各种混合功能的性能，以评估玻尔兹曼电导率。演示示例包括硅和铝块状晶体以及两种热电材料（CoSb ₃，Bi ₂ Te ₃）。我们观察到，混合功能除了提供预期的更现实的带隙以外，还导致更大的带宽，因此可以更好地估计传输特性，甚至在金属系统中也是如此。作为纳米结构原型，我们还研究了氮化硼（BN）取代的石墨烯中的电导率，其中纳米带（纳米）与BN交替出现。