If the redirection operator is >, and the noclobber option to the set builtin has been enabled, the redirection will fail if the file whose name results from the expansion of word exists and is a regular file.
所以应该这样做:
set -o noclobber # or, equivalently, set -C
for r in FE C CR MN SI NI CO MO W NB AL P CU TA V B N O S; do
echo "0" > "data/T1_FCC_X_$r.dat"
done 2> /dev/null