How to create a heterostructure using two monolayers from different crystal systems: a hexagonal system (a = b = 3.17 Å, c = 18 Å, α = β = 90°, γ = 120°) and an orthorhombic system (a = 3.77 Å, b = 4.519 Å, c = 18 Å, α = β = γ = 90°), while ensuring a lattice mismatch of less than 4%?"