Description of the (2s(2))S-1, (2s2p)P-1, (2p(2))D-1, and (1snl)L-1 (n <= 6, l <= 2) states of the helium atom by the variational method

A new theoretical model and a method of calculation of the wave functions o f the autoionization and the (1snl)L-1 states are proposed. The theory is b ased on the method of superposition of configurations and uses an approxima tion of basis functions by a linear combination of hydrogen-like functions with effective charges. The resulting wave functions satisfy all the orthog onality requirements, in the approximation ignoring the non-Coulomb part of the He+ potential, the width of the (2s(2))S-1, (2s2p)P-1, and (2p2)D-1 re sonances and the shift of the resonance positions owing to the interaction with the degenerate continuum were calculated. The results of the calculati ons agree well with the presently available experimental and theoretical da ta.