2.13                      ******************
                                  * PSRCH WRITE-UP *
                                  ******************
        
           PSRCH is a program which searches the map computed by FSFOUR and 
        lists the coordinates and heights for the largest peaks (positive
        or negative). Only unique peaks will be listed. It has other options
        useful in small molecule crystallographic applications, but for
        protein work only the peak list is used, hence the other options are
        bypassed and will not be described. This is essentially the peak
        search program used in the MULTAN78 direct methods programming
        package.  
        
           		INPUT DATA  (UNIT 5)
        
        
          CARD 1      PAMFIL         (free format)
        
                      PAMFIL = Name of input file containing cell parameters 
                               and symmetry information (used only to get 
                               running log file name).
                     
        
          CARD 2      MAPFIL         (free format)
        
                      MAPFIL = Name of map file input.
                
        
          CARD 3      NPEAK, NEGP          (free format)
        
                      NPEAK = Number of largest peaks to list (Max=180)     
                          
                            = 0 gives the default of (11*n)/9 where n = number 
                              of independent atoms (excluding H) as input to 
                              FSFOUR

                      NEGP =  0 to list positive peaks, 1 to list negative
                              peaks
          
        
                                   ***** FILES *****
        
        The input binary map file should be the output file from FSFOUR.  
        FSFOUR must have been run with the parameter NORN=0 specifying the XZ 
        section orientation.