Length, strength, extensibility, and thermal stability of a Au-Au bond in the gold monatomic chain

Simulating the measured size dependence of both the E_4f level shift and the melting-point suppression of Au nanosolids reveals that (i) the E_4f core-level energy of an isolated Au atom is estimated to be -81.50 eV and the E_4f binding energy is -2.87 eV and (ii) the melting point of the Au monatomic chain (MC) is around 320 K, about 1/4.2 times the bulk value (1337.33 K). These intriguing changes are attributed to the effect of atomic coordination imperfection. An analytical solution has been derived showing that the maximal strain of a metallic bond in a MC under tensile stress varies inapparently with the mechanical stress but apparently with temperature in the form of exp[A/(T_m - 4.2T)], where A is a constant and T_m is the bulk melting point. Matching calculations to all the insofar-measured breaking limits (at 4 K, it is around 0.23 nm, and in the vicinity of room temperature, it is 0.29-0.48 nm) indicates that the measured divergent values originate from thermal and mechanical fluctuation near the melting point of the MC.