seq 1 1000 | tr '\n' ' ' | awk '{i=1; j=0 ; k=0 ;while ( i <= NF){printf("ATOM%7d  C   UNK     1%12.3f %7.3f%8.3f  1.00  0.00 UNKA\n",$i,$(i)+k,j,0);i++;if (j == '0') j = 0.75 ; else j = 0; k=k+0.0606}}' > my.pdb