The Normal Helium Atom

Abstract

A least-squares criterion for the goodness of approximate wave functions is proposed. The root-mean-square energy deviation for the six-term Hylleraas function is calculated to be 3.5 volts. It is shown that no ascending power series in the variables ${r}_{1}$, ${r}_{2}$ and ${r}_{12}$ can be a formal solution of the Schr\"odinger equation.