A method is developed to optimize the separated-pair independent particle (SPIP) wave function; it is a special case of the separated-pair theory obtained by using two-term natural expansions of the geminals. The orbitals are optimized by a theory based on the generalized Brillouin theorem and iterative configuration interaction (CI) calculations in the space of the SPIP function and its single excitations. The geminal expansion coefficients are optimized by serial 2 x 2 CI calculations. Formulas are derived for the matrix elements. An algorithm to implement the method is presented, and the work needed to evaluate the molecular integrals is discussed. (auth)

Tracer self-diffusion coefficients were measured as functions of temperature and deviations from stoichiometry. The arc-transfer technique of crystal growth was found to produce crystal of Co/sub 1-x/O of essentially the same purity as the starting Co rod, and the quality was comparable to commercially available crystals grown by Verneuil process. Measurements at x = 0.005 in Co/sub 1-x/O showed the Co tracer self-diffusion coefficient to be D = 3.88 x 10$sup -4$ exp (--31600 +- 2400/RT) cm$sup 2$/s between 1037 and 1350$sup 0$C. This activation energy is in agreement with measurements made in air, if proper compensation is made for the effect of variation in stoichiometry. Measurements on crystals having deviations between 0.002 and 0.008 at 1150$sup 0$C showed the diffusion coefficient to depend on p/sub O$sub 2$/ as D = 9.74 x 10$sup -9$ p/sub O$sub 2$//sup 1/(3.59)/ cm$sup 2$/s, where p/sub O$sub 2$/ varied between 10$sup -2$.$sup 5$ and 10$sup -0$.$sup 25$ atm. Comparison with thermogravimetric and electrical conductivity measurements confirms that the defects responsible for Co diffusion in the range of temperature and p/sub O$sub 2$/ of this investigation are singly ionized cobalt vacancies. The Co tracer self-diffusion coefficients in single crystals are nearly identical to those …

A vector meson dominance model of the electromagnetic form factors of hadrons is developed which is based on the use of unstable particle propagators. Least-square fits are made to the proton, neutron, pion and kaon form factor data in both the space and time-like regions. A good fit to the low-energy nucleon form factor data is obtained using only rho, $omega$, and phi dominance, and leads to a determination of the vector meson resonance parameters in good agreement with experiment. The nucleon-vector meson coupling constants obey simple sum rules indicating that there exists no hard core contribution to the form factors within theoretical uncertainties. The prediction for the electromagnetic radii of the proton is in reasonable agreement with recent experiments. The pion and kaon charge form factors as deduced from the nucleon form factors assuming vector meson universality are compared to the data. The pion form factor agrees with the data in both the space and time-like regions. The pion charge radius is in agreement with the recent Dubna result, but the isovector P-wave pion-pion phase shift calculated from the theory disagrees with experiment. A possible contribution to the form factors from a heavy rho meson is also evaluated. (auth)

Results of studies on the stoichiometry, structure, vaporization behavior, and thermodynamic properties of the Sc--S system are reported. The thermodynamic results for the stability of ScS(s) are compared with reported results for other transition-metal and rare-earth monosulfides. Various models are discussed in regard to their ability to describe the bonding in these refractory solids. (JRD)

The reactions pp $Yields$ pp $pi$$sup +$pi$sup -$ and pp $Yields$ pp$pi$$sup +$$pi$$sup -$$pi$$sup +$$pi$$sup -$ at 200 and 300 GeV/c were investigated using the Fermilab 30-inch hydrogen bubble chamber and downstream wide-gap spark chambers. This analysis is based upon approximately 9500 4- pronged and 6-pronged events. The cross sections were consistent with pomeron dominance for these reactions. The final state pp $pi$$sup +$$pi$$sup -$ is dominated by single diffractive dissociation, whose features are quite similar to those observed at low energy. A strong signal for double excitation was seen in the pp $pi$$sup +$$pi$$sup -$$pi$$sup +$$pi$$sup -$ final state and pomeron factorization was found to be satisfied. In the pp $pi$$sup +$$pi$$sup -$ final state, 66 events passed the criterion of double pomeron exchange defined by D. M. Chew. However, these events were found to be severely contaminated by diffractive events. The two-particle exclusive azimuthal correlations agreed well with the prediction of a photostatistical model. (auth)

A study of the gamma-ray de-excitation following the beta decays of $sup 93$Kr, $sup 93$Rb, and $sup 93$Sr using the TRISTAN on-line separator facility is reported. Gamma-ray singles and gamma-gamma coincidence measurements were made using Ge(Li) detectors. Of the 162 gamma rays observed in the decay of $sup 93$Sr, 143, representing more than 99 percent of the total gamma-ray intensity observed, were placed in a level scheme containing 36 levels. For the decay of $sup 93$Rb, 243 gamma rays were observed, of which 231 are placed in a level scheme consisting of 74 levels. This again represents a placement of over 99 percent of the total gamma-ray intensity measured. In the case of the $sup 93$Kr decay approximately 98.5 percent of the observed gamma-ray intensity has been accounted for by the proposed level scheme. This results from the placement of 203 of the 217 gamma rays assigned to this decay in a level scheme comprising 56 levels. Beta-branching for these decays were determined from transition intensity balances. Spin and parity assignments were proposed, whenever possible, on the basis of gamma-ray transition probabilities and deduced log ft values. A comparison is made with the available reaction data for the $sup 93$Y …