Second-order polarization propagator calculations

S.P.A. Sauer, G.H.F. Diercksen, J. Oddershede, Second Order Polarization Propagator Calculations of Dynamic Polarizabilities and Cs Coefficients, Int. 1. Quantum Chem. 39 (1991) 667. 

Electric moments, polarizabilities, and hyperpolarizabilities for BH were calculated for the first time [23], as were field and field gradient polarizabilities [24]. Spectroscopic properties were calculated for BH using the coupled electron pair approximation. The potential curve for BH was calculated at 22 points and Rq was found to be 1.23115 A and p to be 1.244 D [21]. The radiative lifetime of the A state of BH was calculated from second-order polarization propagator calculations [25], and the singlet-triplet separation in BH was calculated using ab initio MO methods. The latter, described as the singlet-triplet separation, was found to be 31.9 kcal/mol [26]. Finally, the possible dynamical pathways in the system BH + H+ were probed [27]. 

Bak, K. L., Koch, H., Oddershede, J., Christiansen, O., and Sauer, S. P. A. (2000). Atomic integral driven second order polarization propagator calculations of the excitation spectra of naphthalene and anthracene. J. Chem. Phys., 112, 4173-4185. 

The static and dynamic polarizability of the polyyne (C2 H2) series is treated in the TDHF and correlated second order polarization propagator methods by Dalskov et al.2i2 The calculated polarizabilities are extrapolated to the infinitely... 

In this substection we will shortly discuss the computational methods used for calculation of the spin-spin coupling constants. Two main approaches available are ab initio theory from Hartree-Fock (or self-consistent field SCF) technique to its correlated extensions, and density function theory (DFT), where the electron density, instead of the wave function, is the fundamental quantity. The discussion here is limited to the methods actually used for calculation of the intermolecular spin-spin coupling constants, i. e. multiconfigurational self consistent field (MCSCF) theory, coupled cluster (CC) theory and density functional theory (DFT). For example, the second order polarization propagator method (SOPPA) approach is not... 

By the end of the 1980s, state of the art methods of quantum chemistry, such as coupled cluster, configuration interaction, fourth order perturbation theory (MP4), second-order polarization propagator (SOPPA, multiconfigu-rational linear response (MCLR) etc., had been applied to the calculation of... 

Empirical equilibrium coupling constants can be compared as a benchmark with calculated equilibrium coupling constants obtained with various methods. A comparison of these empirical equilibrium constants with calculated equilibrium constants suggested that the restricted-active-space self-consistent field (RASSCF) method is the best approach for calculating the indirect nuclear spin-spin coupling constants of small molecules, and that the second-order polarization propagator approximation (SOPPA) and DFT are similar in performance. 

Second-Order Polarization Propagator Approximation Calculations. -... 

The paramagnetic contribution is more demanding to calculate and is a bit more sensitive to electron correlation, although not a great deal. For instance, for ammonia, the RPA (effectively uncorrelated) value is 38.45 ppm a.u., while the Second Order Polarization Propagator Approximation (correlated) yields 38.15 ppm a.u. 

C-C Coupling constants calculated using second order polarization propagator approach (SOPPA) are in a good agreement with the available experimental data and can be used for conformational analysis in the N-containing carbonyl derivatives (Figure 12.48). ... 

Relativistic calculations of NMR properties of RgH ion (where Rg = Ne, Ar, Kr, Xe), Pt shielding in platinum complexes, and Pb shielding in solid ionic lead(II) halides have been reported in this review period. For the Rg nucleus in the RgH ions, the following methods were used and results compared with each other non-relativistic uncorrelated method (HF), relativistic uncorrelated methods, four component Dirac Hartree-Fock method (DHF) and two-component zeroth order regular approach (ZORA), non-relativistic correlated methods using second order polarization propagator approach SOPPA(CCSD), SOPPA(MP2), respectively coupled cluster singles and doubles or second order Moller-Plesset, and... 

The computational study of the one-bond carbon-silicon couplings has been performed at the second-order polarization propagator approximation (SOPPA) level by Rusakova et oZ. in a series of 60 various silanes and compared with the experimental Vcsi values taken from the literature. A special attention has been paid by the authors to the main factors affecting the accuracy of the calculation including the level of theoiy, the quality of the basis set, and the contribution of solvent and relativistic effects. The reported in the paper values have been obtained at the SOPPA(CC2) level, whereas for the calculations of solvent and... 

The contributions of the second order terms in for the splitting in ESR is usually neglected since they are very small, and in feet they correspond to the NMR lines detected in some ESR experiments (5). However, the analysis of the second order expressions is important since it allows for the calculation of the indirect nuclear spin-spin couplings in NMR spectroscoi. These spin-spin couplings are usually calcdated via a closed shell polarization propagator (138-140), so that, the approach described here would allow for the same calculations to be performed within the electron Hopagator theory for open shell systems. 

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