The zeroth-order regular approximation ~ZORA! is used for the evaluation of the electric field gradient, and hence nuclear quadrupole coupling constants, in some closed shell molecules. It is shown that for valence orbitals the ZORA-4 electron density, which includes a small component density ~‘‘picture-change correction’’!, very accurately agrees with the Dirac electron density. For hydrogen-l...

The ISOLDE Collaboration CERN, CH-1211 Geneva 23, Switzerland (Received 19 March 1998; revised manuscript received 19 October 1998) The electric quadrupole interaction of 191Pt (I ­ 3y2; T1y2 ­ 2.9 d) in an Fe single crystal was measured for magnetization M parallel to the crystallographic [100], [110], and [111] axes. For M k f111g and [110] the distribution of the electric field gradient (EFG...

Electrostatic potential (EP), electric field (EF), and electric field gradient (EFG) values are calculated in periodic models of magnesium substituted phillipsite (MgPHI) zeolite forms using periodic DFT (PDFT) hybrid B3LYP level with fourteen different basis sets. Relative root mean square differences between the EP, EF, or EFG values estimated between different basis sets are evaluated in sev...

Accurate, yet simple and efficient, formulae are presented for calculation of the electrostatic potential (ESP), electric field (EF) and electric field gradient (EFG) from the aspherical Hansen-Coppens pseudoatom model of electron density [Hansen & Coppens (1978). Acta Cryst. A34, 909-921]. They are based on the expansion of |r' - r|(-1) in spherical harmonics and the incomplete gamma function ...