A small-core multiconfiguration Dirac-Hartree-Fock-adjusted pseudopotential for Tl - application to Tl X ( X = F, Cl, Br, I)

Abstract

A relativistic pseudopotential of the energyconsistent variety simulating the Tl 21 (1s ± 4f ) core has been generated by adjustment to multicon®guration Dirac±Hartree±Fock data based on the Dirac±Cou-lomb±Breit Hamiltonian. Valence ab initio calculations using this pseudopotential have been performed for atomic excitation energies and for spectroscopic constants of the X0 and A0 states of TlX (X = F, Cl, Br, I). Comparison is made to experiment and to four-component density functional results.A relativistic energy-consistent PP for Tl has been derived, using the following atomic valence Hamiltonian:Correspondence to: H. Stoll

Accuracy of relativistic energy-consistent pseudopotentials for superheavy elements 111–118: Molecular calibration calculations

“…This choice of the core is analogous to the one successfully used for the 5d transition metals as well as the post-5d main group elements. [26][27][28][29] Note that a larger core including also the 6(spd)-shells leads to lower accuracy, which already has been demonstrated for the lighter homologues of element 113. [29][30][31] …”

Correlation consistent basis sets for explicitly correlated wavefunctions: Pseudopotential-based basis sets for the post-d main group elements Ga–Rn

“…All of the basis sets of this work are paired with small core, multiconfigurational Dirac-Hartree-Fock-adjusted pseudopotentials of the Stuttgart-Cologne variety 19,20,22,23 (replacing 10 electrons for Ga-Kr, 28 electrons for In-Xe, and 60 electrons for Tl-Rn), which were previously employed in the cc-pVnZ-PP family of basis sets for these elements. [18][19][20] …”

“…[15][16][17] In the present work, new F12-based correlation consistent basis sets, denoted cc-pVnZa) Electronic addresses: grant.hill@sheffield.ac.uk and kipeters@wsu.edu PP-F12, have been developed for all the post-d main group elements Ga-Rn. These sets are derived from the standard augcc-pVnZ-PP and aug-cc-pwCVnZ-PP sets, [18][19][20][21] which were constructed for use with small-core relativistic pseudopotentials of the Stuttgart-Cologne variety, 19,20,22,23 and also complement the standard all-electron correlation consistent basis sets, valence and core-valence, for these elements. [24][25][26] To accompany the new orbital basis sets of this work, new auxiliary basis sets have also been determined that are needed for density fitting of the standard 2-electron integrals (MP2FIT), as well as for the resolution of the identity of the many-electron F12 integrals (OPTRI).…”

Role of nuclear volume in driving equilibrium stable isotope fractionation of mercury, thallium, and other very heavy elements

“…This means that the 1s orbital of each hydrogen atom, for instance, is optimized as a linear combination of two groups of Gaussian basis functions. Inner-shell electrons of mercury and thallium atoms are treated in a further simplified manner, using relativistic pseudopotentials (Metz et al, 2000;Figgen et al, 2005), while wave functions of valence and intermediate-shell electrons are constructed from a double-zeta contraction (cc-pVDZ-PP, Peterson, 2003;Peterson and Puzzarini, 2005). Molecular structures are optimized until residual forces acting on each atom are less than 1.5 · 10 À5 Hartree/bohr (%1.2 · 10 À12 Newton).…”