Visibility map tips
This is a new window -- resize it for simultaneous viewing of your Live3D model.
Lattice fringes are visible over a wider range of angles if crystals are thinner in the direction of the beam. Microscopes thus see particular lattice spacings only if they're both able to resolve those spacings, and the viewing direction is within the thickness-dependent band of visibility for that spacing. Fringe-visibility maps describe the fringes a microscope will see on crystals of given thickness, plus the orientation relationship between those fringes. Such maps thus characterize the fringe patterns seen in a collection of randomly-oriented nanoparticles*, and can guide tilt experiments to fully determine the lattice of any specific particle**. Their layout is like that of Kikuchi maps*** except that larger lattice spacings give rise to wider, rather than narrower, bands. Blank spaces (external to fringe bands) on the "visibility sphere" represent orientations at which no lattice fringes are seen. You can read more about fringe visibility maps here.
Microscope orientations are referenced to a given lattice by zone (or direct lattice uvw) indices, while crystallographic planes are described by Miller (or reciprocal lattice hkl) indices. Zones are perpendicular to lattice plane-normals when uh+vk+wl=0, and therefore label intersections between planes. When crystals are cubic, zones are also parallel to plane-normals with similar indices. Zone indices for the current viewing direction can be listed by clicking the [Zone Indices] button. Likewise, angular rotation distances between the present viewing direction, and the last indexed zone, can be determined under any viewing conditions by clicking the [Angle to LastZone] button.
The frames host for this page is (http://www.umsl.edu/~fraundor/nanowrld/live3Dmodels/vpmapframe.htm). As an experimental page, there are no guarantees of correctness, and suggestions toward improvement are invited. Although there are many contributors, the person responsible for errors is P. Fraundorf. This site is hosted by the Department of Physics and Astronomy (and Center for Molecular Electronics) at UM-StLouis.