A proposed modification of the exchange-correlation magnetic field in density functional theory is implemented into the all-electron full-potential linearized augmented-plane-wave code Fleur. By removing terms from the magnetic field that stem from source contributions not found for physical ones, a recent paper has shown that theprediction of Fe magnetic moments in iron pnictide materials can be improved vastly while conserving the accurate description of simpler materials. The theory justifyingthe idea is explored and the physicality of the modification is discussed. The interaction of the modification with different kinds of magnets is highlighted, the possibleconstraints in application are explained and justified and the results are compared to those from the original paper calculated via the Elk code. Furthermore, theeffect on the coupling parameters in a Heisenberg model is investigated to gain greater insight about how the modification works and why the improvements happen
