Helium Atom Wave Functions from Slater Orbitals of Nonintegral Principal Quantum Number

Slater orbitals of nonintegral principal quantum number have been used to construct a He ground-state wave function of the form Ψ=c1(ns,n′s)+c2(n′′p)2+c3(n′′′d)2+c4(n′′′′f)2.The variation method has been employed to determine the five orbital exponents, the five principal quantum numbers n, and the four linear coefficients. The minimized energy is 0.0058 a.u. above the nonrelativistic limit of —2.9037 a.u. computed by Pekeris. This may be compared with a difference of 0.0063 a.u. obtained by Taylor and Parr upon minimizing the energy of the same wave function constrained to have integral principal quantum numbers.