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Numerous excited molecular terms for the various alkali-rare gas atom pairs have been determined. The semiempirical potential model of Baylis has been used with some modifications in the calculation of the molecular terms; in particular, a large number of atomic states are included in our calculation, which ensure the stability of the calculated molecular terms. Our results show that coupling among molecular terms is very important and gives rise to structure in the excited potential energy curves. Comparisons between our results and other theoretical and experimental data are made.

Electron-capture cross sections for H+ plus alkali-metal atom (Na, K, Rb, and Cs) systems have been computed for projectile energies from 10 eV to 10 keV. An impactparameter perturbed-stationary-state theory using molecular states that incorporate electron translation factors was used to calculate the cross sections. The wave functions were generated by employing the pseudopotential method. These yield equilibrium parameters R, and D, for the A X+ molecular state that are in good agreement with ab initio results.Interaction energies are also presented for the LiH+ system. Basis sets of up to eight molecular states were used to calculate the electron-capture cross sections from ground (ns) as well as from the first excited (np) states of the alkali-metal atoms. Results for electron capture from the ground-state alkali-metal atom are in good agreement with the recent experiments of Nagata. Electron capture from excited alkali-metal (np) atoms does not yield enhanced cross sections relative to capture from the ground state and, in fact, shows decreased cross sections for the heavy alkali-metal atoms. Such behavior is contrary to predictions made using arguments based on the magnitude of the energy gap AE to the electron-capture product states.

Measurement error can be very difficult to assess and reduce. While great strides have been made in the field of survey methods research in recent years, many ongoing federal surveys were initiated decades ago, before testing methods were fully developed. However, the longer a survey is in use, the more established the time series becomes, and any change to a questionnaire risks a break in that time series. This article documents how a major federal survey -the health insurance module of the Current Population Survey (CPS) -was redesigned over the course of 15 years through a systematic series of small, iterative tests, both qualitative and quantitative. This overview summarizes those tests and results, and illustrates how particular questionnaire design features were identified as problematic, and how improvements were developed and evaluated. While the particular topic is health insurance, the general approach (a coordinated series of small tests), along with the specific tests and methods employed, are not uniquely applicable to health insurance. Furthermore, the particular questionnaire design features of the CPS health module that were found to be most problematic are used in many other major surveys on a range of topic areas.

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