seq 1 7 | tr '\n' ' ' | awk '{ResNum= $1 ; AtomNum=1; j=0 ; l=1; d=0; b=0.75; dd = b*(3^(0.5)); yy = b; \
while ( ResNum <= NF) {\
printf("ATOM%7d  N   UNK%6d%12.3f%8.3f%8.3f  1.00  0.00 UNKA\n", AtomNum,   ResNum, d,          j,             0); \
printf("ATOM%7d  CA  UNK%6d%12.3f%8.3f%8.3f  1.00  0.00 UNKA\n", AtomNum+1, ResNum, d+(dd),    -j+yy,          0); \
printf("ATOM%7d  CB  UNK%6d%12.3f%8.3f%8.3f  1.00  0.00 UNKA\n", AtomNum+4, ResNum, d+(dd),   (-j+yy)+(l*yy),  l*dd); \
printf("ATOM%7d  C   UNK%6d%12.3f%8.3f%8.3f  1.00  0.00 UNKA\n", AtomNum+2, ResNum, d+(2*dd),   j,             0); \
printf("ATOM%7d  O   UNK%6d%12.3f%8.3f%8.3f  1.00  0.00 UNKA\n", AtomNum+3, ResNum, d+(2*dd),   j+(-l*2*b),      0); \
ResNum++; \
AtomNum = AtomNum + 5; \
d = d + 3*dd; \
if (j == '0') j = yy ; else j = 0 ;  if (l == '1') l = '-1' ; else l = 1 ; \
} \
AtomNum = AtomNum + 5; \
printf("ATOM%7d  O   UNK%6d%12.3f%8.3f%8.3f  1.00  0.00 UNKA\n", AtomNum,   ResNum, d,          j,             0); \
}'