Starting PHENIX nightly build version 1.6-295 (or whatever next version), the new command line tool phenix.maps is available. As the name suggests, this is the tool for map calculation: regular (p*Fobs-q*Fcalc) or maximum-likelihood (p*mFobs-q*DFcalc), with any user-defined coefficients p and q, as many as requested. For example, 2mFo-DFc, 3Fo-2Fc, mFo-DFc, Fc, Fo, Anomalous difference maps can be all computed at once. Also, a user has a full control over various map calculation parameters, such as filling missing Fobs with DFc, computing kick maps, etc. Maps can be output in X-plor formatted files or as Fourier map coefficients in MTZ formatted file. X-plor formatted maps can be computed for the whole molecule/unit cell or any selected part of the structure. This new tool is meant to be a replacement for current practice of computing the maps using phenix.refine (although, phenix.refine still output maps as before). For more information and usage examples simply run phenix.maps . This is available from PHENIX GUI too (thanks Nathaniel Echols). For usage instructions and quick manual type phenix.maps and hit Enter. Please let me know should any questions or problems related to using this tool arise. Pavel. P.S. Below is the result of running phenix.maps: phenix.maps: a command line tool to compute various maps. How to run: 1. Run phenix.maps without any arguments: just type phenix.maps in the command line and hit Enter. This will create a parameter file called maps.params, which can be renamed if desired. 2. Edit maps.params file to specify input/output files and the desired maps. It is possible to request as many maps as desired. 3. Run this command to compute requested maps: phenix.maps maps.params Remarks: - The scope of parameters 'map_coefficients' defines the map that will be output as Fourier map coefficients. The scope of parameters 'map' defines the map that will be output as X-plor formatted map. - To create several maps: duplicate either 'map_coefficients' or 'map' or both scopes of parameters as many times as many maps is desired. Then edit each of them to define the maps. - A map is defined by specifying a map type using 'map_type' keyword available within each scope of parameters: 'map_coefficients' or 'map'. The general supported format for 'map_type' is: [p][m]Fo+[q][D]Fc[kick][filled]. For example: 2Fo-Fc, 2mFobs-DFcalc, 3Fobs-2Fmodel, Fo-Fc, mfobs-Dfcalc, anom. The 'map_type' parser will automatically recognize which map is requested. - The program creates as many files with X-plor formatted maps as many X-plor formatted maps is requested, and it creates only one MTZ formatted file with all Fourier map coefficients in it. - The X-plor formatted map can be computed in the entire unit cell or around selected atoms only. - Kick maps and missing Fobs filling is done (if requested) as described in Adams et al. (2010). Acta Cryst. D66, 213-221. - Twinning (if detected) will be accounted for automatically. - All arrays used in map calculation, for example: Fobs, Fmodel, Fcalc, Fmask, m, D, etc., can be output into a CNS or MTZ formatted reflection file.