Semiempirical Pseudopotential Method for Low-Dimensional Materials

In recent years, there has been a significant focus on developing precise and efficient approaches to expedite Density Functional Theory (DFT) calculations for large unit cells. Among these techniques, the Semiempirical Pseudopotential Method (SEPM) [1] has emerged as a valuable tool for accurately determining band structures, especially in the realm of low-dimensional materials. SEPM operates by utilizing atomic pseudopotentials, which are derived from DFT calculations. Significantly, SEPM calculations offer a unique advantage compared to DFT as they eliminate the requirement for iterative self-consistent solutions in solving the Schrödinger equation, leading to a substantial reduction in computational complexity.<br/>The incorporation of both non-local and local Semiempirical Pseudopotentials in our current approach yields band structures and wavefunctions with enhanced precision compared to traditional empirical methods [2]. When applied to graphene, our model's computed band structure closely aligns with that obtained via DFT calculations [3]. Impressively, our method demands only a fraction of the time required in comparison to the CG iterative solver with self-consistent charge density from DFT. Additionally, we utilized the SEPM technique for armchair graphene nanoribbons (aGNR), achieving results that closely align with those obtained through DFT, but with significantly reduced computational time. Furthermore, we extended the application of our SEPM approach to monolayer TMDCs, adjusting the parameters to align with pertinent values obtained from DFT computations. This enables us to faithfully replicate the band structure, opening avenues for investigating the optoelectronic properties of TMDCs and exploring their potential applications in nanodevices consisting of TMDC nanostructures or related moir[endif]--&gt; structures.<br/><br/><b>References</b><br/>[1] Paudel, R.K.; Ren, C.-Y.; Chang, Y.-C. Semi-Empirical Pseudopotential Method for Graphene and Graphene Nanoribbons. Nanomaterials 2023, 13,2066<br/>[2] Chelikowsky, J.R.; Cohen, M.L. Nonlocal pseudopotential calculations for the electronic structure of eleven diamond and zinc-blende semiconductors. Phys Rev B. 1976, 14, 556.<br/>[3] Ren C.Y.; Hsue, C.S.; Chang Y.C. A Mixed Basis Density Functional Approach for Low-Dimensional Systems with B-splines. Computer Physics Communication. 2015, 188, 94-102