Qmatsim

Qmatsim is a multiscale simulation framework for strain engineering in two-dimensional materials. It combines density functional theory (DFT) calculations using SIESTA with molecular dynamics (MD) simulations via LAMMPS to study the interplay between mechanical deformation and electronic structure in layered materials. The framework implements the computational methodology described in Alawein et al., Physical Review Materials 2025.

The primary focus is on transition metal dichalcogenides (TMDs), with built-in material libraries covering MoS2, MoSe2, WS2, and WSe2. The simulation pipeline enables study of flat bands induced by strain, lateral heterostructure formation at material interfaces, and emergent electronic phases that arise from controlled lattice deformation. Automated flat-band discovery routines scan parameter spaces to identify strain configurations that produce flat electronic bands, which are of interest for correlated electron physics.

Spin-orbit coupling calculations are integrated into the DFT workflow, capturing the strong spin-orbit effects characteristic of TMDs containing heavy transition metals like tungsten. SLURM automation scripts manage job submission and dependency chains for high-performance computing clusters, enabling large-scale parameter sweeps across strain magnitudes and crystallographic orientations.

Qmatsim links to the qubeml project, which provides educational Jupyter notebooks covering quantum transport in graphene and MoS2 via the Kwant module, and is referenced by the scicomp cross-platform computing framework. The repository is hosted at github.com/alawein/qmatsim and is in active development within the materials-science domain at P2 priority.