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  Purpose : Interpolation of natpot terms to another grid.
  Usage   : chnpot [-D -d -rd -w -mnd -nf -nd -ver-h -?] input 

 Options  : 
 -D PATH  : The output is directed to PATH. 
            This option overwrites "name" in the run-section of the input file.
 -d DIR   : The old dvr is read from file DIR/dvr. This option overwrites 
            "dvrdir" in the run-section of the input file.
 -rd DIR  : The new dvr is read from directory DIR. If DIR is missing, 
            name is assumed. This option sets/overwrites 
            "readdvr" in the run-section of the input file.
 -w       : Overwrite existing files in name directory.
 -mnd     : Make Name Directory. Creates the name directory, if not existent.
 -nf FILE : The natpot is read from file FILE. This option overwrites 
            "natpotfile" in the run-section of the input file.
 -nd DIR  : The natpot is read from file DIR/natpot. This option overwrites 
            "natpotdir" in the run-section of the input file.
 -ver     : Version information about the program 
 -h       : Print this help text. 
 -?       : Print this help text. 

  The argument "input" is the file containing the Run-Section, the new 
  Primitive-Basis-Section, and the Fit-Section. 
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