Evaluation of Approximate Exchange-Correlation Functionals in Predicting One-Bond (31)P-(1)H NMR Indirect Spin-Spin Coupling Constants.
This work benchmarks density functional theory, with several different exchange-correlation functionals, for prediction of isotropic one-bond phosphorus-hydrogen NMR spin-spin coupling constants (SSCCs). Our test set consists of experimental SSCCs from 30 diverse molecules representing multiple phosphorus bonding environments. The results suggest the importance of a balance between the choice of correlation functional and the admixture of nonlocal exchange. Overall, standard DFT methods appear to suffice for usefully accurate predictions of (31)P-(1)H SSCCs.
The objective of this paper is to study the arbitrage free pricing of the covariance swap for Barndorff–Nielsen and Shephard (BN–S) type Levy process driven financial markets. One of the major challenges in arbitrage free pricing of swap is to obtain an accurate pricing expression which can be used with good computational accuracy. In this paper, we obtain analytic expressions for the pricing of the covariance swap. We show that with the analytic expressions obtained from the BN–S model, the error estimation in fitting the delivery price is much less than the existing models with comparable parameters. The models and pricing formulas proposed in this paper are computable in real time and hence can be efficiently used in practical applications.