It was previously suggested that a metal-organic framework [Zn-2(C8H4O4)(2)center dot C6H12N2] could be a possible candidate for observation of parity violation effects related to tunneling of C6H12N2 (DABCO) fragment between chiral twisted states. We have performed relativistic four-component and two-component calculations of parity violating energy (PVE) term for twisted isomers of isolated DABCO molecule and [Zn(2)DABCO](4+) cation. We also discuss the nature of PVE in these systems with the help of analysis of individual atomic contributions to PVE and visualization of electron chirality density. (C) 2017 Elsevier B.V. All rights reserved.