Dramatic relativistic and magnetic Breit effects for the superheavy reaction Og + 3Ts2 → OgTs6: prediction of atomization energy and the existence of the superheavy octahedral oganesson hexatennesside OgTs6

Our gargantuan ab initio all-electron fully relativistic Dirac–Fock (DF), nonrelativistic (NR) Hartree–Fock (HF) and Dirac–Fock-Breit-Gaunt (DFBG) molecular SCF calculations for the superheavy octahedral oganesson hexatenniside OgTs6 predict atomization energies (AEs) of 9.49, −5.54 9.37 eV, at optimized Og-Ts bond distances 3.35, 3.44 3.36 Å, respectively. There are dramatic effects relativity energy (with seven atoms 820 electrons) ~15.0 eV both DF DFBG levels theory. calculated reaction Og + 3Ts2 → NR, theory exoergic by 8.81, 6.33 6.26 The contribution to dispersion interactions increases 0.94–7.20 eV. AEs form 6Ts be NR level (that is, is unstable relative sum its constituent atoms) 9.49 theory, Dispersion increase AE(DFBG) 1.30–10.67 Ours first interaction corrected with electrons. Mulliken population analysis (MPA) as implemented in DIRAC code our (using dyall.cv4z basis) yields charges Og+0.60 Og+0.96, respectively, on central atom indicating that less ionic compared HF calculations. However, due caution must used interpret results MPA, which highly basis set dependent.