Preparing for ARP/wARP 

Before you actually start arping and warping there are a few things to do:

• Create a directory where you are going to run ARP/wARP $\!\!$.  It is important that you create a separate directory for each project and name it appropriately.
• Copy to this directory the MTZ file containing all your necessary data. The file must contain:

  1.

  Native data structure factor amplitudes and their sigmas (these are required for any ARP/wARP application). If for some reason you want to use different sets of structure factor amplitudes for the initial map calculation - include them as well.

  2.

  An R $_{\rm free}$ column should better be present in you data file even if you are not planning to use it. We would suggest to run all your MTZ files through the CCP4 script UNIQUIEFY which will take care of lots of things).

• Run arp_warp_setup.sh and answer the questions.