A problem arises in electronic structure calculations involving some generalised self-consistency condition. Examples are the self-consistency of the potential or the magnetic moment, the latter being discussed here in detail. The problem reduces to ensuring that when one requires analytic consistency between different quantities the numerical method used must preserve the analytic relation to arbitrary precision. Specifically the authors deal with the recursion method coupled with Gaussian quadrature for the calculation of the integrated density of states and show that the conventional prescription for the evaluation of the total energy fails to satisfy the analytic condition that its minimum correspond to the self-consistent solution. They illustrate the magnitude of the effect and a way to overcome it using examples from a model density of states and a real calculation.