The coupled cluster calculations taking into account relativistic effects to study spectroscopic and chemical properties of element 120 (E120) are performed. A generalized relativistic effective core potential for the 10 explicitly treated electrons of E120 atom was generated to perform molecular calculations. Similar calculations for Ba are also done and they are in a good agreement with the experimental data. Dissociation energies of diatomic X-H and X-Au molecules, where X = E120, Ba, are calculated; for E120 they are found to be 15-2 times smaller than those for Ba. (C) 2012 Elsevier B.V. All rights reserved.