#!/usr/bin/awk -f

BEGIN {count=0; natom=0; fbohr=0.529177; a0=0.0; scale=0.0;}

/lattice parameter / {a0 = $5 * fbohr; }
/number of atoms\/cell/ { natom = $5;  }

# coordinates at the beginning of a run.
/ positions \(a_0 units\)/ {print natom; print "step: ", count;}
/ *tau\(...\) =/ {
	printf "%4s %12.4f %12.4f %12.4f\n", $2, $7*a0, $8*a0, $9*a0;
}

# coordinates during geometry optimization.
/ATOMIC_POSITIONS \(.+\)/ { 
	++count; 
        print natom; print "step: ", count;
	if ($2 == "(angstrom)") { 
		scale = 1.0; 
	} else {
		print "unknown coordinate scaling";
	}
	for (i=0; i<natom; ++i) {
		getline;
		printf "%4s %12.4f %12.4f %12.4f\n", \
			$1, $2*scale, $3*scale, $4*scale;
	}
}