diff --git a/my_pyscf/lassi/excitations.py b/my_pyscf/lassi/excitations.py
index 4ef69f56..450da8b2 100644
--- a/my_pyscf/lassi/excitations.py
+++ b/my_pyscf/lassi/excitations.py
@@ -14,7 +14,7 @@
 op = (op_o0, op_o1)
 
 LOWEST_REFOVLP_EIGVAL_THRESH = getattr (__config__, 'lassi_excitations_refovlp_eigval_thresh', 1e-9)
-IMAG_SHIFT = getattr (__config__, 'lassi_excitations_imag_shift', 0.0001)
+IMAG_SHIFT = getattr (__config__, 'lassi_excitations_imag_shift', 1e-6)
 
 def only_ground_states (ci0):
     '''For a list of sequences of CI vectors in the same Hilbert space,