# Kolmogorov-Crespi Potential For Multilayer Transition Metal Dichalcogenides: Capturing Structural Transformations In Moir\'e Superlattices

## TL;DR

This paper develops a Kolmogorov-Crespi potential for multilayer transition metal dichalcogenides, enabling efficient structural relaxation of moiré superlattices with results comparable to DFT, facilitating studies of their electronic properties.

## Contribution

It introduces a new interlayer potential for TMDs and a mixing rule for heterostructures, allowing accurate and efficient modeling of moiré superlattices.

## Key findings

- KC potential accurately reproduces DFT relaxations
- Relaxed structures yield similar electronic band structures to DFT
- Enables efficient study of structural and electronic features in TMD moiré systems

## Abstract

We develop parameters for the interlayer Kolmogorov-Crespi (KC) potential to study structural features of four transition metal dichalcogenides (TMDs): MoS$_2$, WS$_2$, MoSe$_2$ and WSe$_2$. We also propose a mixing rule to extend the parameters to their heterostructures. Moir\'e superlattices of twisted bilayer TMDs have been recently shown to host shear solitons, topological point defects and ultraflatbands close to the valence band edge. Performing structural relaxations at the DFT level is a major bottleneck in the study of these systems. We show that the parametrized KC potential can be used to obtain atomic relaxations in good agreement with DFT relaxations. Furthermore, the moir\'e superlattices relaxed using DFT and the proposed forcefield yield very similar electronic band structures.