Phototransition of Na(3p3/2) into high Rydberg states and the ionization continuum

A model potential method is used to investigate photoabsorption from the Na(3p3/2) state. Absorption cross sections into higher Rydberg states and photoionization cross sections are presented as an analytical function of photo electron energy. Einstein coefficients for spontaneous emissions 3p3/2 ← ns1/2, nd5/2, nd3/2 are tabulated for n up to 50. The Einstein coefficients and low-energy ionization cross sections are believed to be accurate to better than 2–3%, above 1 eV the error may increase to 4–6%.

A semi-empirical extrapolation technique for atomic and molecular properties derived from correlated wavefunctions

Abstract A semi-empirical extrapolation technique is suggested for recovering the correlation defect remaining in atomic and molecular properties calculated from highly correlated wavefunctions. These procedures are applied to PNO-CEPA and PNO-IPPA calculations on F, F + , F − , and HF in order to obtain “exact” estimates of the ionization potential, electron affinity, and dissociation energy.

Configuration Expansion by Means of Pseudonatural Orbitals

The configuration interaction (CI) method as a general approach to solving the many-electron Schrodinger equation to—in principle—any desired accuracy, has been described in this volume by Shavitt. We refer to that chapter for all basic concepts of the CI method and an outline of its merits and its computational problems.

Finite perturbation calculation for the static dipole polarizabilities of the atoms Na through Ca

PNO-CI and CEPA studies of electron correlation effects

Ab initio calculations of the potential curves of low laying electronic states of OH are performed on the basis of a variational configuration interaction wavefunction (PNO-CI) and the coupled electron pair approximation (CEPA). The latter approach yields a ground state potential curve which deviates from the RKR curve by less than 200 cm−1 in the region from 0.7 to 1.6 A. Calculated ground state constants are as follows (experimental values in parentheses): r e = 0.972 (0.971) A, B e = 18.85 (18.87) cm−1, α e = 0.727 (0.714) cm−1, ω e = 3742 (3739) cm−1, ω e χ e = 85.3 (86.4) cm−1, μ0 = 1.686 (1.66) D, D e = 4.35 (4.63) eV,IP = 12.78 (13.36?) eV, El.Aff. = 1.51 (1.83) eV, v 00(2Π↔2Σ+) = 32…

Finite perturbation calculations for the static dipole polarizabilities of the first-row atoms

Static dipole polarizabilities are calculated from self-consistent-field and highly correlated wave functions for the ground states of the atoms Li through Ne. The correlation contributions to the polarizabilities are found to vary between -16% for Be and + 14% for F. The polarizabilities as obtained from the coupled-electron-pair approximation are expected to be accurate to about 2%.