Data Mining for New Two- and One-Dimensional Weakly Bonded Solids and Lattice-Commensurate Heterostructures

Layered materials held together
by weak interactions including van der Waals forces, such as graphite,
have attracted interest for both technological applications and fundamental
physics in their layered form and as an isolated single-layer. Only
a few dozen single-layer van der Waals solids have been subject to
considerable research focus, although there are likely to be many
more that could have superior properties. To identify a broad spectrum
of layered materials, we present a novel data mining algorithm that
determines the dimensionality of weakly bonded subcomponents based
on the atomic positions of bulk, three-dimensional crystal structures.
By applying this algorithm to the Materials Project database of over
50,000 inorganic crystals, we identify 1173 two-dimensional layered
materials and 487 materials that consist of weakly bonded one-dimensional
molecular chains. This is an order of magnitude increase in the number
of identified materials with most materials not known as two- or one-dimensional
materials. Moreover, we discover 98 weakly bonded heterostructures
of two-dimensional and one-dimensional subcomponents that are found
within bulk materials, opening new possibilities for much-studied
assembly of van der Waals heterostructures. Chemical families of materials,
band gaps, and point groups for the materials identified in this work
are presented. Point group and piezoelectricity in layered materials
are also evaluated in single-layer forms. Three hundred and twenty-five
of these materials are expected to have piezoelectric monolayers with
a variety of forms of the piezoelectric tensor. This work significantly
extends the scope of potential low-dimensional weakly bonded solids
to be investigated.