[phenixbb] refinement for non-standard DNA base

Hi, I have 5-fluoro-Uracil in my DNA:protein complex. I modeled 5-F-dU into the map, ran eLBOW for geometry file and did refinement. After the refinement, 5-F-dU is not connected to the neighboring nucleotides and the phosphate oxygens are rotated to wrong positions. Can anyone teach me how to refine with non-standard DNA base ? Any help or advice would be appreciated. John