2.35                      ********************
                                  * RMHEAVY WRITE-UP *
                                  ********************


          This program is used to temporarily remove electron density near
        heavy atom sites from an input map, so that a solvent mask can be
        accurately created from the map via the automatic boundary procedure.
        The strong density often found near heavy atom sites in initial
        MIR or SIR maps can lead to an extension of the protein mask near
        the heavy atom sites. Since these sites are nearly always on the
        protein surface, the effect is that the protein envelope can 
        incorrectly extend into the solvent region (and if the envelope is
        tight, therefore be depleted elsewhere in the protein region).
        A list of heavy atom sites is read in along with a map and a distance
        cutoff. The atoms are expanded by space group symmetry, and if
        any grid point is within the cutoff distance from any atom in the
        expanded list, its electron density value is set to zero. The
        modified map is then output. Note that this map is normally used
        ONLY for the purpose of SOLVENT MASK GENERATION. The original MIR
        or SIR map is still used for all solvent flattening computations.
        The procedure DOALL.SH will automatically accomplish this, provided
        the file names in the supplied template procedures are adhered to.
        If one does not wish to do this, simply comment out the two lines

                           rmheavy < rmhv.d >> mask1.l
                           mv nohv.map four.map

        in each of the files mask1.sh, mask2.sh and mask3.sh

        Typically the input file will contain coordinates of all heavy
        metals that were used in the phasing, and a distance cutoff of
        about 2.5 angstroms.


                            INPUT DATA  (UNIT 5)

        RECORD 1    PAMFILE      (free format)

                    PAMFILE = Input parameter file specifying cell and
                              symmetry information.


        RECORD 2    INPMAP       (free format)

                    INPMAP = Input map file (full cell, from FSFOUR)


        RECORD 3    OUTMAP       (free format)

                    OUTMAP = Output map file (full cell, as in input)

      
        RECORD 4    NA, RAD      (free format)

                    NA  =  Number of input heavy atom sites 

                    RAD =  Distance cutoff, in angstroms.


        the NA input atomic coordinate records now follow

        RECORDS 5   ATNAME, X, Y, Z, B, OCC, ITYPE      FORMAT(7X,A8,5F10.5,I5)
            
          ATNAME = not used
            
           ITYPE = not used
            
            OCC  = not used
            
          X,Y,Z  = Fractional atomic coordinates
            
             B   = not used

        Note that the coordinate format is identical to that used in PHASIT,
        thus a copy of the earlier phasing deck can be made and edited for
        use here.


                                ***** FILES *****

        INPUT MAP  - Standard FSFOUR map, covering a full cell

        OUTPUT MAP - Same format as input map, but with heavy atom
                     density removed