def write(self, outfile='<STR_LIT>',<EOL>header_string='<STR_LIT>'):
dcols=['<STR_LIT>', '<STR_LIT>','<STR_LIT>']<EOL>data=[self.z,self.names,self.abu]<EOL>hd=[header_string]<EOL>att.write(outfile,hd,dcols,data)<EOL>
Write initial abundance file (intended for use with ppn)

Parameters
----------
outfile : string
    Name of output file.  The default is
    'initial_abundance.dat'.
header_string : string
    A string with header line.  The default is
    'initial abundances for a PPN run'.