Conical intersections (CIs) play an important role in the nonadiabatic molecular processes. Earlier we obtained, that the Renner effect in polyatomic molecules is accompanied by symmetry-allowed CI. Later Vertesi and Englman showed that two aligned CIs will be created in the slightly bent C2H2+ cation. This finding was also supported by us. Here additional ab initio calculations were performed to map the seams of the CIs in the configuration space. We could show that increasing the displacement value of the H1 atom from the CC axis one of the seams of the CIs begin to migrate and finally disappear. (C) 2010 Elsevier B. V. All rights reserved.