Relativistic bonding effects

The total energy in ab initio theory is given relative to the separated particles, i.e. bare nuclei and electrons. The experimental value for an atom is the sum of all the ionization potentials for a molecule there are additional contributions from the molecular bonds and associated zero-point energies. The experimental value for the total energy of H2O is —76.480 a.u., and the estimated contribution from relativistic effects is —0.045 a.u. Including a mass correction of 0.0028 a.u. (a non-Bom-Oppenheimer effect which accounts for the difference between finite and infinite nuclear masses) allows the experimental non-relativistic energy to be estimated at —76.438 0.003 a.u. ... 

Hakkinen, H., Moseler, M. and Landman, U. (2002) Bonding in Cu, Ag, and Au Clusters Relativistic Effects, Trends, and Surprises. Physical Review Letters, 89, 033401-1-033401-4. 

Schwerdtfeger, P. and Bowmaker, G.A. (1994) Relativistic effects in gold chemistry. V. Group 11 Dipole-Polarizabilities and Weak Bonding in Monocarbonyl Compounds. Journal of Chemical Physics, 100, 4487-4497. 

In the complex xenon functions as a n-donor toward Au2+. This is reflected in the calculated charge distribution within the cation, where the main part of the positive charge resides on the xenon atoms. Relativity plays a large role in stabilizing this and other predicted Au—Xe compounds about half of the Au—Xe bonding energy comes from relativistic effects.1993... 

The growing importance of quantum-chemical calculations is dealt with in a short section, with emphasis on the consideration of relativistic effects, especially in systems containing mercury. These calculations aim at optimization of structures, determination of bond energies, simulation of spectra, and estimation of spectral parameters, independent of but complementary to experiments. 

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