

1. There is common block for general structure description: /CRYSTL/
   with cell parameters, space group definition, matrix to convert
   fract. coordinetes to orthogonal and vice versa (FRTOCR,CRTOFR)

   Some subroutines to control the content common block /CRYSTL/:      

     SET_CELL - put parameters to common/CRYSTL/,
               calc reciprocal cell parameters,volume and calc matrix 
               FRTOCR and CRTOFR

     GET_CELL - get parameters from common/CRYSTL/
 

     REPCELL -  using CELL parameters from common/CRYSTL/ calc reciprocal
                cell parameters,volume and calc matrix FRTOCR and CRTOFR





2. Subroutines to read/write files of F, phases, ABCD, Almn coefficients.

   This subroutines uses common blocks /COMRDF/ and /COMWRF/   
   for read/write title of file.

   Some subroutines to control the content this common block:      

   C_RD_CR  - copy information from common/COMRDF/ to common/CRYSTL/
              also using CELL parameters from common/CRYSTL/ calculates
              reciprocal cell parameters,volume and calc matrix 
              FRTOCR and CRTOFR

   C_CR_WR  - copy information from common/CRYSTL/ to common/COMWRF/

   C_RD_WR  - copy information from common/COMRDF/ to common/COMWRF/

   GET_TITLE  - get information from /COMRDF/
   SET_TITLE  - set information to   /COMWRF/

   SET_WRF    - put N_SpGr, N_SETT, CODE_SpGr, CODE_PDB to common/COMWRF/
                        NAME_PDB, DATE_PDB , TITLE_PDB

   read/write subroutines:


   ORFILE - 1.open file.
            2.reads title of file and copy file_parameters to /COMRDF/.

   OPFILE - 1.don't open file, rewind file 
            2.reads title of file and copy file_parameters to /COMRDF/.

   OWFILE - 1.open file.  
            2.writes title to file from common /COMWRF/

   RD     - read from file; type of file :"F   ","PH  ","COEF","ALMN"
   RRD    - read from file; type of file :"FS  "
   RD1    - read from file; type of file :"F   ","PH  ","COEF","ALMN"
   RRD1   - read from file; type of file :"FS  "
   RD2    - read from file; type of file :"F   ","PH  ","COEF","ALMN"
   RRD2   - read from file; type of file :"FS  "
   RD3    - read from file; type of file :"F   ","PH  ","COEF","ALMN"
   RRD3   - read from file; type of file :"FS  "
   RD4    - read from file; type of file :"F   ","PH  ","COEF","ALMN"
   RRD4   - read from file; type of file :"FS  "
   RABCD  - read from file; type of file :"ABCD"
   RABCD1 - read from file; type of file :"ABCD"

   WRT    - write to file; type of file :"F   ","PH  ","COEF","ALMN"
   WWRT   - write to file; type of file :"FS  "
   WRT1   - write to file; type of file :"F   ","PH  ","COEF","ALMN"
   WWRT1  - write to file; type of file :"FS  "
   WABCD  - write to file; type of file :"ABCD"
   WABCD1 - write to file; type of file :"ABCD"




3. Subroutines to read/write density file:

   Subroutines to read open file and use common block /COMRDF/ to keep
   title

    RDENS  - reads density file, put current section of map to real array. 
    RDENS2 - reads density file, put current section of map to real array. 
    IRDENS - reads density file, put current section of map to integer array. 
    IRDNS2 - reads density file, put current section of map to integer array. 

   Subroutine to write does not open file and you have to control content
   of common block/COMWRF/ ( subroutines C_CR_WR,SET_TITLE) and to use  
   subroutine: OWFILE before.

    WDENS  - write current section of map to file 



4. Subroutines to read/write coordinate files:

   This subroutines uses common blocks: /CRDINF/,/CRD2INF/,/CRD3INF/,
   /CRDATM/,/CRD2ATM/,/CRD3ATM/ for read/write title of file and coordinates.

   Some subroutines to control the content this common blocks:      

   C_CR_AT  - copy information from common/CRYSTL/  to common/CRDINF/

   C_AT_CR  - copy information from common/CRDINF/  to common/CRYSTL/
              also using CELL parameters from common/CRYSTL/ calculates
              reciprocal cell parameters, volume and calc matrix 
              FRTOCR and CRTOFR

   C_CR2_AT - copy information from common/CRYSTL/  to common/CRD2INF/

   C_AT_CR2 - copy information from common/CRD2INF/ to common/CRYSTL/     
              also using CELL parameters from common/CRYSTL/ calculates
              reciprocal cell parameters, volume and calc matrix 
              FRTOCR and CRTOFR

   C_CR3_AT - copy information from common/CRYSTL/  to common/CRD3INF/

   C_AT_CR3 - copy information from common/CRD3INF/ to common/CRYSTL/
              also using CELL parameters from common/CRYSTL/ calculates
              reciprocal cell parameters, volume and calc matrix 
              FRTOCR and CRTOFR

    read/write subroutines:


    ORCRD  - 1. open file for read.
             2. reads title of file to common/CRDINF/
    RDCRD  - reads coordinates to common/CRDATM/

    ORCRD2 - 1. open file for read.
             2. reads title of file to common/CRD2INF/
    RDCRD2 - reads coordinates to common/CRD2ATM/

    ORCRD3 - 1. open file for read.
             2. reads title of file to common/CRD3INF/
    RDCRD3 - reads coordinates to common/CRD3ATM/

    OWCRD  - 1. open file for write.
             2. writes title from common/CRDINF/ to file
    WRCRD  - writes coordinates from common/CRDATM/ to file.

    OWCRD2 - 1. open file for write.
             2. writes title from common/CRD2INF/ to file
    WRCRD2 - writes coordinates from common/CRD2ATM/ to file.



5. Easy way to understand how to use BLANC subroutines is to look at
   the example-programs in "blanc/prog" directory:

     read_sf.f    - read/write structure factor files
     read_dns.f   - read/write density files
     read_crd.f   - read/write coordinate files
     reaf_atoms.f - read/write coordinate files and keep all atoms in memory.

   Programs use include files from "blanc/for" directory:

     nsym-max.fh
     atom-com.fh

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