Low valencies and periodic trends in heavy element chemistry. A theoretical study of relativistic effects and electron correlation effects in Group 13 and Period 6 hydrides and halides

1992 ◽  
Vol 114 (19) ◽  
pp. 7518-7527 ◽  
Author(s):  
Peter Schwerdtfeger ◽  
Graham A. Heath ◽  
Michael Dolg ◽  
Martin A. Bennett
Keyword(s):  
Electron Correlation ◽  
Heavy Element ◽  
Theoretical Study ◽  
Relativistic Effects ◽  
Correlation Effects ◽  
Group 13 ◽  
Element Chemistry ◽  
Electron Correlation Effects

Energy spectra of the tungsten ion 4s24pN, 4s24N–14d and 4s4pN+1 configurations

2015 ◽  
Vol 55 (3) ◽  
Author(s):  
Pavel Bogdanovich ◽  
Rasa Karpuškienė ◽  
Romualdas Kisielius
Keyword(s):  
Energy Level ◽  
Configuration Interaction ◽  
Electron Correlation ◽  
Relativistic Effects ◽  
Energy Spectra ◽  
Correlation Effects ◽  
Interaction Method ◽  
Configuration Interaction Method ◽  
Hartree Fock ◽  
Electron Correlation Effects

The ab initio quasirelativistic Hartree–Fock approximation was used to determine spectroscopic parameters for the multicharged tungsten ions with an open 4p shell. The configuration interaction method based on the transformed radial orbitals was applied to include the electron-correlation effects. The relativistic effects were taken into account in the Breit–Pauli approximation for the quasirelativistic Hartree–Fock radial orbitals. The complete energy level spectra were calculated for the 4s24pN, 4s24pN–14d and 4s4pN+1 configurations of the tungsten ions from W43+ to W38+.

Relativistic and Electron Correlation Effects as a Tool for Explaining Some Trends in Molecular Properties and Interactions

2006 ◽  
Vol 1 (1) ◽  
pp. 259-265 ◽  
Author(s):  
Miroslav Urban ◽  
Vladimír Kellö
Keyword(s):  
Electron Affinity ◽  
Electron Correlation ◽  
Heavy Atom ◽  
Lone Pair ◽  
Relativistic Effects ◽  
Electric Properties ◽  
Molecular Properties ◽  
Cluster Method ◽  
Correlation Effects ◽  
Electron Correlation Effects

In this paper we discuss relatively routine Douglas–Kroll–Hess spin–free relativistic calculations as a tool for understanding some trends of molecular properties within the series of related molecules. Electron correlation effects are considered by the Coupled Cluster method with iterative treatment of the single and double excitation operators and perturbative treatment of triples, CCSD(T). For our analysis we use accumulated data on relativistic effects on ionization potentials, electron affinities and polarizabilities of the coinage elements, Cu, Ag, and Au and related series like Ia and IIa group elements. Next we analyze electric properties of diatomic molecules as CuF, AgF, and AuF, and compare electric properties and bonding energies of these molecules with intermetalics CuAl, AgAl, AuAl. Electric dipole moments and dipole polarizabilities of the series of oxides including a heavy atom, GeO, SnO, and PbO in their 1∑ ground states are also analyzed. Particular attention is paid to the dissociation energy of PbO and its electron affinity. The bonding character of the MeL series of complexes (Me=Cu, Ag, Au; L=H2O, NH3, and H2S) is explained by stressing the importance of the charge transfer from the lone pair of the ligand to the metal element. Relativistic effects which affect the Me electron affinity and polarizability facilitate understanding the trends of Me interactions with different ligands. We also mention using of the optimized virtual orbital space (OVOS) as an instrument which allows to circumvent problems with proper contraction needed for a specific approximate relativistic Hamiltonian. OVOS allows to reduce the computer time of correlated relativistic calculation by an order of magnitude.

Quantifying electron-correlation effects in small coinage-metal clusters by ab initio calculations

2021 ◽  
Author(s):  
Victor Giovanni de Pina ◽  
Bráulio Gabriel Alencar Brito ◽  
Guo -Q Hai ◽  
Ladir Cândido
Keyword(s):  
Monte Carlo ◽  
Ab Initio Calculations ◽  
Ab Initio ◽  
Electron Correlation ◽  
Metal Clusters ◽  
Correlation Effects ◽  
Diffusion Monte Carlo ◽  
Coinage Metal ◽  
Electron Correlation Effects ◽  
Fixed Node

We investigate many-electron correlation effects in neutral and charged coinage-metal clusters Cun, Agn, and Aun (n = 1 − 4) by ab initio calculations using fixed-node diffusion Monte Carlo (FN-DMC)...

BS DFT and BS HDFT studies of CrCr sextuple bond from the viewpoint of electron correlation effects

2009 ◽  
Vol 109 (14) ◽  
pp. 3315-3324 ◽  
Author(s):  
Yasutaka Kitagawa ◽  
Yasuyuki Nakanishi ◽  
Toru Saito ◽  
Takashi Kawakami ◽  
Mitsutaka Okumura ◽  
...  
Keyword(s):  
Electron Correlation ◽  
Correlation Effects ◽  
Electron Correlation Effects

Nonnuclear Maxima in the Charge Density

1993 ◽  
Vol 48 (1-2) ◽  
pp. 127-133 ◽  
Author(s):  
Kenneth E. Edgecombe ◽  
Vedene H. Smith, Jr. ◽  
Florian Müller-Plathe
Keyword(s):  
Charge Density ◽  
Electron Density ◽  
Electron Correlation ◽  
Basis Set ◽  
Valence Shell ◽  
Correlation Effects ◽  
Electron Correlation Effects

Abstract Basis-set and electron-correlation effects on the appearance and disappearance of nonnuclear maxima in the electron density are examined in Li2 , Na2 , Na4 and Na5 . It is shown that nonnuclear attractors can be removed in all cases except Li2 . The appearance of a pseudoatom in a lithium molecule correlates remarkably well with the size of the region, in an atomic calculation, of V2r(r) for the valence shell of the atom. This and the fact that the pseudoatom is also present in the promolecule indicate that the pseudoatoms are remnants of, or in fact are portions of, atoms that are not perturbed enough in the molecule to remove an essentially atomic characteristic.

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