Table 2. Abbreviations of performed refinements.

Abbreviations	Method used	Effects included
rks-anh_nr	Non-relativistic rks/B3LYP with anharmonic nuclear motions of Au	Electron correlation, anharmonicity
rks_rel	Relativistic rks/B3LYP with harmonic nuclear motions	Relativistic effects, electron correlation
rhf-anh_rel	Relativistic rhf with anharmonic nuclear motions of Au	Relativistic effects, anharmonicity
rks-anh_rel	Relativistic rks/B3LYP with anharmonic nuclear motions of Au	Relativistic effects, electron correlation, anharmonicity
Abbreviations	Difference between refinements	Effect observed
REL	rks-anh_rel – rks-anh_nr	Relativistic effects
ECORR	rks-anh_rel – rhf-anh_rel	Electron correlation
ANH	rks-anh_rel – rks_rel	Anharmonicity