Routes to identification of intrinsic twist in helical MoS2 nanotubes by electron diffraction and annular dark-field scanning transmission electron microscopy imaging

Objective molecular dynamics simulations coupled with a density functional-based tight-binding model indicated that a stress-free single-walled ($14,6$) MoS${}_{2}$ nanotube exhibits a torsional deformation of 0.87 deg/nm. Simulated electron diffraction patterns and atomic-resolution annular dark field scanning transmission electron microscopy (ADF-STEM) images of the computed nanotube structures show promise that this peculiar feature can be identified experimentally. The small intrinsic twist removes the translational periodicity prescribed by the rolled-up construction and defines a nanotube for which the atomic order is most fundamentally described by the objective structures concept.