Ground State Properties of Hg₂. 1. A Pseudopotential Configuration Interaction Study

Abstract

The results of large-scale relativistic ab initio pseudopotential calculations for the potential curve of the 1 Σ g + (0 g + ) ground state of the mercury dimer Hg 2 are reported. Various methods to account for electron correlation effects have been applied in the ΛΣ coupling scheme, and spin-orbit contributions were derived from calculations in the intermediate coupling scheme. The importance of correlating the 5s,5p core orbitals in addition to the 5d core and 6s valence orbitals and of spin-orbit corrections is demonstrated. At the highest level of approximation the calculated spectroscopic constants (R e ) 3.73 Å, D e ) 0.047 eV, ω e ) 19 cm -1 ) are in excellent agreement with the experimental results (R e ) 3.63 ( 0.04 Å, D e ) 0.043 ( 0.003 eV, ω e ) 18.5 ( 0.5 cm -1 ).

TheG0u+(61P1)–X0G+Excitation and Fluorescence Spectra of Hg2Excited in a Supersonic Jet

“…10. To find the unique comparison is also made with the calculations of Czuchaj value n for the van der Waals function to make it overlap et al (12) and Dolg and Flad (21,22) whose result agrees with the points obtained by the inversion method, it was most closely with our experimental curves. The repulsive necessary to assume the van der Waals X 0 / g ground state part of the ground state potential obtained by the inversion potential with the parameter n as a free variable, simulate method (18) and the van der Waals potential with n Å 6.21 the bound-free band using this potential, and vary n to lie closer to the van der Waals curve with n Å 6.53 (3) than obtain the best fit between the observed and simulated posi-to the Morse curve.…”

“…/ u and X 0 / g States of Hg 2 pulsed free-jet supersonic expansion beam crossed with a cent result of Dolg and Flad (21,22), suggests that relativistic effects should be included in ab initio calculations for pulsed dye-laser beam. A well-resolved vibrational structure the massive Hg 2 molecule.…”

The effect of the iterative triple and quadruple cluster amplitudes on the adiabatic potential curve in the coupled cluster calculations of the ground electronic state of the Yb dimer

“…The details of the used procedure can be found elsewhere [28]. The feature of this procedure is the use of the DFT method instead of the methods with explicit description of electron-electron interactions as, e.g., in article [13]. The former allows one to use the essentially larger basis set in contrast to article [13] for the calculations with accounting for the spinorbit interactions.…”

“…For example, only three contracted p-type functions were used in Ref. [13] to describe the different radial parts of the 5p 1/2 and 5p 3/2 outercore and 6p virtual pseudospinors in calculations with the 20 explicitly treated electrons per each Hg atom, whereas 11 p-type functions were used in [25] for calculations of Yb with the 42 electrons. The other feature is that effects of electronic correlations are taken into account within DFT, so the additivity of the correlations and spin-orbit effects is irrelevant to (is not exploited in) our study.…”

“…Refs. [13] and [14]). The only attempt [9] to estimate the role of spin-orbit interactions for the ground state of Yb 2 was made with the use of the two-electron PP, in which accuracy is not expected to be high enough.…”