we have used only 700 basis functions (six-dimensional gaussoids) with carefully optimized non-linear parameters. It should be mentioned here that highly accurate wave functions can be constructed with the use of 2000 (or more) basis functions (six-dimensional gaussoids) with carefully optimized non-linear parameters. The explicit construction of such accurate wave functions with 2000 terms (or more) does not require excessive computational resources, but in calculations performed for this study we restrict ourselves to bound state wave functions with $N = 700$ terms only. There are two reasons for this. First, we compare our bound state properties with analogous properties computed in earlier papers (see, e.g., [@King91] and references therein) where the total number of basis functions used was $\approx 500 - 800$, which is comparable to 700. Second, many differences between accurate bound state properties obtained with $N = 700$ basis functions in Eq.(\[gauss\]) and highly accurate values determined with $N = 2000$ basis functions in Eq.(\[gauss\]) are of interest for some special purposes only. The overall accuracy of our computed bound state properties is sufficient to predict the results of various experiments performed for three-electron atomic systems. Moreover, our results obtained for the three-electron atomic systems presented in Tables 