  We perform extensive density functional theory (DFT) calculations to
determine the stability and elementary properties of 4249 previously unexplored
monolayer crystals. The monolayers comprise the most stable subset (energy
within 0.1 eV/atom of the convex hull) of a larger portfolio of two-dimensional
(2D) materials recently discovered using a deep generative model and systematic
lattice decoration schemes. The relaxed 2D structures are run through the basic
property workflow of the Computational 2D Materials Database (C2DB) to evaluate
the dynamical stability and obtain the stiffness tensor, piezoelectric tensor,
deformation potentials, Born and Bader charges, electronic band structure,
effective masses, plasma frequency, Fermi surface, projected density of states,
magnetic moments, magnetic exchange couplings, magnetic anisotropy, topological
indices, optical- and infrared polarisability. We provide statistical overviews
of the property data and highlight a few specific examples of interesting
materials. Our work exposes previously unknown parts of the 2D chemical space
and provides a basis for the discovery of 2D materials with specific
properties. All data is available in the C2DB.
