[phenixbb] Real space vs reciprocal refinement

Dear phenixbb! In the current version of phenix.refine contains the separate option for refinement: xyz (reciprocal space) and xyz (real space ). What does it mean and how it differs from the previous versions which had xyz and real space instead. So I just wanted to know what does it actually do? Can we run both of them simultaneously? Is it advisable to do both refinement for DNA ? - Mahesh India.