Evaluation and comparison of configuration interaction calculations for complex atoms
Charlotte F. Fischer
Configuration interaction (CI) methods are the method of choice for the determination of wave functions for complex atomic systems from which a variety of atomic properties may be computed. When applied to highly ionized atoms where few, if any, energy levels from observed wavelengths are available, the question arises as to how a calculation may be evaluated. Many different codes are available for such calculations. Is agreement between the results from different codes in itself a check on accuracy? This paper reviews basic theory which, when applied in a systematic manner, can be the basis for the evaluation of accuracy. Results will be illustrated in the study of 4s24p5 (odd) and 4s4p6, 4s24p44d (even) levels in W39+ and transitions between them.