diff --git a/dpdata/qe/scf.py b/dpdata/qe/scf.py
index c2530b7c..7b6a70aa 100755
--- a/dpdata/qe/scf.py
+++ b/dpdata/qe/scf.py
@@ -128,8 +128,6 @@ def get_energy(lines):
 
 def get_force(lines, natoms):
     blk = get_block(lines, "Forces acting on atoms", skip=1)
-    if len(blk) == 0:
-        raise RuntimeError("no force found in the output file.")
     ret = []
     blk = blk[0 : sum(natoms)]
     for ii in blk: