Two relevant isomers were determined, an A conformer where all linkers of a paddle wheel point up or down, and a B conformer where opposing linkers on one paddlewheel point in opposite directions (see Figure ). Conformer A was found to be "rigid" (i.e. not transforming Copyright 2020, Zenodo. Recently, a more realistic modelling using nanodomains of differing conformers lead to an even better understanding of the real crystal system. The reverse transition of opening the structure from its cp phase to the op phase can be achieved by adsorbing guest molecules. Under the range of guest molecules able to reopen flexible DUT-8(Ni) are CO2 and CH4.