CONAN─Novel Tool to Create and Analyze Liquids in Confined Space.

Modeling of complex liquids at solid surfaces and in confinement is gaining attention due to an increase in computer power and advancement of simulation techniques. Therefore, tools to set up structures and for analysis are needed. In this paper, we present CONAN─a Python code designed to facilitate the study of liquids interacting with solid structures, such as walls or pores. Among other things, the program provides the option to generate a variety of different structures, including carbon walls and nanotubes and their boron nitride analogs, as well as the ability to analyze various structural properties of confined and interfacial liquids. In the case of the ionic liquid 1-butyl-3-methylimidazolium acetate in carbon nanotubes of different sizes, we demonstrate the abilities of our tool. The average density within the confinement highly depends on the carbon nanotube size, and it is generally lower than the density of the bulk liquid. The arrangement of the individual species within the tube also depends on size, with radial layers forming within the tubular confinement. The density is largely increased in the respective layers, while it is drastically reduced between the layers.