ZIB

Hits per page

hits 1 - 2 | 2 hits

Sorting

Electronic Resource

Pseudopotential approaches to Ca, Sr, and Ba hydrides. Why are some alkaline earth MX2 compounds bent? (1991)

Kaupp, M. ; Schleyer, P. v. R. ; Stoll, H. ; [et al.]

College Park, Md. : American Institute of Physics (AIP)

The Journal of Chemical Physics 94 (1991), S. 1360-1366

add to mindlist on the mindlist

Details

ISSN: 1089-7690

Source: AIP Digital Archive

Topics: Physics , Chemistry and Pharmacology

Notes: Quasirelativistic and nonrelativistic 10-valence-electron pseudopotentials for Ca, Sr, and Ba are presented. Results of calculations with 6s6p5d basis sets for MH, MH+, and MH2 are compared with all-electron and 2-valence-electron pseudopotential calculations with and without core-polarization potentials. The 10-valence-electron pseudopotential approach agrees well with all-electron calculations. It circumvents problems for the 2-valence-electron pseudopotentials arising from an incomplete separation of valence and subvalence shells in polar molecular systems due to strongly contracted occupied (n−1)-d orbitals. All higher-level calculations show SrH2 and BaH2 to be bent with angles of ∼140° and 120°, respectively, while CaH2 is linear with a flat potential-energy surface for the bending motion. The use of a core-polarization potential together with the 2-valence-electron pseudopotential approach allows an investigation of the relative importance of core-polarization vs direct d-orbital bonding participation as reasons for the bent structures. The calculations strongly suggest that both contribute to the bending in SrH2 and BaH2. Even at the Hartree–Fock level of theory 10-valence-electron pseudopotential calculations given reasonable angles when the potential-energy surface is not exceedingly flat, and only moderately contracted basis sets including both compact d functions and diffuse p functions are used. The effect of core-valence correlation and the importance of f functions also are discussed.

Type of Medium: Electronic Resource

URL: http://dx.doi.org/10.1063/1.459993

Permalink

Library	Location	Call Number	Volume/Issue/Year	Availability

Others were also interested in ...

Paper (German National Licenses)

Fulltext

Electronic Resource

Pseudopotential calculations for methyl compounds of zinc and magnesium (1990)

Kaupp, M. ; Stoll, H. ; Preuss, H.

New York, NY [u.a.] : Wiley-Blackwell

Journal of Computational Chemistry 11 (1990), S. 1029-1037

add to mindlist on the mindlist

Details

ISSN: 0192-8651

Keywords: Computational Chemistry and Molecular Modeling ; Biochemistry

Source: Wiley InterScience Backfile Collection 1832-2000

Topics: Chemistry and Pharmacology , Computer Science

Notes: Pseudopotentials and valence basis sets to be used in calculations for organometallic compounds of zinc and magnesium have been tested in calculations for the M(CH3)n (M = Zn, Mg; n = 1,2) molecules. Valence correlation effects are treated at the SDCI and CEPA levels. The capability of a polarization potential on zinc to account for the valence shell contracting effect of core valence correlation is studied. Properties considered are geometries, force constants, Mulliken populations, ionization potentials, atomization, and binding energies. Differences in bonding between the two dimethyl compounds are discussed.

Additional Material: 1 Ill.