Effects of Electron Correlation in Xhyphen;Ray and Electron Diffraction. II. Influence of Nuclear Charge in Twohyphen;Electron Systems

摘要

The electronmdash;electron and electronmdash;nuclear radial distribution functionsP(r12) andD(r) have been calculated for ground states of heliumlike systems (Z=2 to 8). Computations were based on the correlated and uncorrelated wavefunctions published by Roothaanet al.Elastic and inelastic scattering factors for calculating the intensitiesI(open phi) of x rays scattered by twohyphen;electron systems were determined from the distribution functions. The correction functions Dgr;P(r12) and Dgr;I(open phi) representing the differences between correlated and uncorrelated results were found to follow a simple dependency on atomic number. It was observed that universal functions could be established which closely approximated each of the functionsD(r)/Z*,P(r12)/Z*,I(open phi), Dgr;P(r12), andZ*Dgr;I(open phi) for all of the systems studied if the functions were expressed in terms of the reduced variablesrprime;=Z*rand open phiprime;=2 arcsinZ*minus;1sin(open phi/2). The appropriateZ*was very nearly the Slater effective nuclear charge. The experimental determination ofP(rij) from xhyphen;ray scattering and the magnitude of correlation effects to be expected are briefly discussed.