Ab initio calculations on cofacial dimers of palladium bis(glyoximates) are reported and are used to rationalize the temperature-dependent conductivity of the low-dimensional, partially-oxidized material Pd(dpg)(2)(0.20+)(I-5(-))(0.20) (dpg = diphenylglyoximato). The band structure near the Fermi level is dominated by two bands, of b(3g) and a(u) symmetry in the dimer, that arise from the ligand pi orbitals. Near the observed (dpg)(2)Pd-Pd(dpg)(2) staggering angle (90 degrees), the b(3g) bandwidth is zero, and the a(u) band exhibits sharp variations with librational (twist) motion about the intermolecular Pd-Pd vector. This in turn, combined with the narrow bandwidth (calculated to be similar to 0.60 eV in a tight-binding model) implies that the electronic states are localized and that the material should be a hopping semiconductor rather than a molecular metal, in agreement with experiment.

AN EFFECTIVE CORE POTENTIAL AB-INITIO STUDY OF ELECTRONIC-STRUCTURE AND BANDWIDTH-CHARGE TRANSPORT RELATIONSHIPS IN LOW-DIMENSIONAL, PARTIALLY OXIDIZED PALLADIUM GLYOXIMATES

DI BELLA, Santo;LANZA, GIUSEPPE;
1995-01-01

Abstract

Ab initio calculations on cofacial dimers of palladium bis(glyoximates) are reported and are used to rationalize the temperature-dependent conductivity of the low-dimensional, partially-oxidized material Pd(dpg)(2)(0.20+)(I-5(-))(0.20) (dpg = diphenylglyoximato). The band structure near the Fermi level is dominated by two bands, of b(3g) and a(u) symmetry in the dimer, that arise from the ligand pi orbitals. Near the observed (dpg)(2)Pd-Pd(dpg)(2) staggering angle (90 degrees), the b(3g) bandwidth is zero, and the a(u) band exhibits sharp variations with librational (twist) motion about the intermolecular Pd-Pd vector. This in turn, combined with the narrow bandwidth (calculated to be similar to 0.60 eV in a tight-binding model) implies that the electronic states are localized and that the material should be a hopping semiconductor rather than a molecular metal, in agreement with experiment.
1995
ELECTRONIC-STRUCTURE; BANDWIDTH-CHARGE TRANSPORT ; PALLADIUM GLYOXIMATES
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/20.500.11769/30429
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