ABSTRACT

The study of lattice mechanical properties of transition metals using pseudopotential is burdensome as the presence of d-band in these metals complicates their electronic structure. The use of pseudopotential for the study of physical properties can be justified if it accounts for the effect of d-band. The local form of the pseudopotentials is widely used to study the physical properties of materials due to their computational simplicity, physical transparency, and transferability to other environments. It is a well-established fact that non-local pseudopotentials should be preferred to the local ones. But, non-local pseudopotentials are proven to be at a higher computational cost. Inspired by such requirements, we, in the present communication, propose a pseudopotential comprising of one non-local (energy-dependent) and another local term in q-space. The non-local (energy-dependent) term accounts for s-p interaction, while the other term is used to account for the effect of s-d hybridisation. The Generalized Pseudopotential Theory (GPT) has been used to formulate the pseudopotential. Further, the pseudopotential has been used to study static binding energy, lattice dynamics, lattice mechanical properties and second-order elastic constants in the long-wavelength limit (q→0) for transition metals γ-Fe (fcc), Co and α-Fe (bcc). Computed results are found to be in good agreement with experimental and other theoretical results, which proves that the proposed pseudopotential itself accounts for the effect of d-band without using additional short-ranged Born–Mayer type potential and effective valency.

摘要

使用赝势研究过渡金属的晶格机械性能是繁重的，因为这些金属中 d 带的存在使它们的电子结构复杂化。如果考虑到 d 波段的影响，使用赝势来研究物理性质是合理的。赝势的局域形式因其计算简单、物理透明和可转移到其他环境而被广泛用于研究材料的物理性质。非局部赝势应该优于局部赝势，这是一个公认的事实。但是，非局部赝势被证明具有更高的计算成本。受这些要求的启发，我们在本次来文中，提出一个赝势，它由 q 空间中的一个非局部（能量相关）和另一个局部项组成。非局部（能量相关）项说明 sp 相互作用，而另一项用于说明 sd 杂交的影响。广义赝势理论 (GPT) 已被用于制定赝势。此外，赝势已被用于研究过渡金属 γ-Fe (fcc)、Co 和 α- 在长波长极限 (q→0) 下的静态结合能、晶格动力学、晶格机械性能和二阶弹性常数。铁 (bcc)。发现计算结果与实验和其他理论结果非常吻合，