Molecules

Another installment in the annals of the bullying of the Shockley surface state, this time the trick isn’t exotic adatoms or massive molecular weight, just a 120° tilt of hexaazatriphenylene (HAT) ligands that converts an achiral lattice into a pair of enantiomeric 2-D metal–organic frameworks. The result: chirality-imposed scattering potentials that lift degeneracies and open ΔE ≈ 80 meV gaps in the Ag(111) two-dimensional electron gas while leaving the global periodicity intact. ...

9-azidophenanthrene produces a rich manifold of products when deposited on Ag(111). The images we took for this study inspired this work to develop a lightweight script to count the molecules we observed, and categorize them. Our personal journey of computer vision rediscovery led us to Zernike moments, a rotationally invariant basis set that solves the problem of identifying the same molecules with relative rotations, in an image. We put some effort into making this module user-friendly, the example scripts offer a reasonable template to apply to any old SXM file you might want to histogram. ...