The density functional definition of exchange and correlation differs from the traditional one. In order to calculate the density functional theory ~DFT!, quantities accurately, molecular Kohn–Sham ~KS! solutions have been obtained from ab initio wave functions for the homonuclear diatomic molecules Li2, N2, F2. These afford the construction of the KS determinant Cs and the calculation of its t...

Multi-reference effects can be covered by density functional theory (DFT) either implicitly via the exchange-correlation functional or explicitly via the form of the Kohn-Sham wave function. With the help of the exchange hole it is shown that the self-interaction error of the exchange functional will mimic long-range electron correlation effects if restricted Kohn-Sham theory is used. Functiona...

In time-distance helioseismology, wave travel times are measured from the cross-correlation between Doppler velocities recorded at any two locations on the solar surface. However, one of the main uncertainties associated with such measurements is how to interpret observations made in regions of strong magnetic field. Isolating the effects of the magnetic field from thermal or soundspeed perturb...

We propose approximations which go beyond the local-density approximation for the short-range exchange and correlation density functionals appearing in a multideterminantal extension of the Kohn-Sham scheme. A first approximation consists of defining locally the range of the interaction in the correlation functional. Another approximation, more conventional, is based on a gradient expansion of ...

We provide novel evidence of priced correlation risk in the foreign exchange market. Currencies that perform badly (well) during periods of high exchange rate correlation have high (low) average returns. We also show that high (low) interest rate currencies have high (low) correlation risk exposure, providing a risk-based justification for the carry trade. To address our empirical findings, we ...