F. Wang et al., A simplified scheme for relativistic density functional computation in thezeroth-order regular approximation, CHEM P LETT, 316(3-4), 2000, pp. 318-323
A simplified scheme for relativistic density functional computations in the
zeroth-order regular approximation (ZORA) to the Dirac equation is present
ed. The potential function in the kinetic energy operator is approximated b
y the potential generated from the superposition of the charge of the const
ituting atoms. The transition state method and ESA are adopted in bonding e
nergy calculations to eliminate the gauge dependence error of the ZORA meth
od. A two-step procedure is adopted to solve the ZORA equation: the scalar
relativistic ZORA equation is first solved self-consistently, then the spin
-orbit interaction is incorporated into the computation. The spin-orbit cou
pling matrix is made real by adopting the symmetry functions of irreducible
representations of relevant double groups as basis sets and properly choos
ing their phase to avoid the complex arithmetic. The calculated results for
several molecules show that this simplified scheme can be satisfactorily u
sed for theoretical studies of compounds containing fairly heavy elements.
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