#### Zeo++

Zeo++ is a software package for analysis and assembly of crystalline porous materials. Zeo++ can be used to perform geometry-based analysis of structure and topology of the void space inside a material, to alternate or assembly structures as well as to generate structure representations to be used in structure similarity calculations.

Zeo++ calculates the geometrical parameters describing pores. The tool is based on the the fast Voronoi decomposition, which for a given arrangement of atoms in a periodic domain provides a graph representation of the void space. The resulting Voronoi network is analyzed to obtain the diameter of the largest included sphere and the largest free sphere, which are two geometrical parameters that are frequently used to describe pore geometry. Accessibility of nodes in the network is also determined for a given guest molecule and the resulting information is later used to retrieve dimensionality of channel systems as well as in Monte Carlo sampling of accessible surfaces and volumes. Pore size distribution histograms can also be calculated. Zeo++ can also generate a number of structure representations. For example, the Voronoi network can be also used to generate hologram representations of the void space. Alternatively, stochastic ray trace approach can provide another histogram representation of the void space. These structure representations can be used to compare materials, i.e. perform diversity selection of structures from a large set.

Zeo++ offers structure alternation capabilities. For example, it can be used to substitute Si atoms with Al atoms in zeolites on the course of generation of cation-containing zeolite structures. It can also assembly 3D structure models of materials such as metal organic frameworks or covalent organic frameworks from a given set of molecular building blocks. The latter feature can be used to construct databases of predicted material structures.

Zeo++ can be used to either analyze a single structure or perform high-throughput analysis of a large database, and makes use of the fast Voronoi library - Voro++. Current users include the Nanoporous Materials Genome Center, the Materials Project, Bosch, ExxonMobile, SABIC and Samsung.