diff --git a/pyscf/tdscf/_lr_eig.py b/pyscf/tdscf/_lr_eig.py
index 9b8e664262..d1eb444b2c 100644
--- a/pyscf/tdscf/_lr_eig.py
+++ b/pyscf/tdscf/_lr_eig.py
@@ -445,25 +445,25 @@ def eig(aop, x0, precond, tol_residual=1e-5, nroots=1, x0sym=None, pick=None,
         xt_norm = np.linalg.norm(xt, axis=1)
         xt_to_keep = (dx_norm > tol_residual) & (xt_norm > max(lindep**.5, tol_residual))
         xt = xt[xt_to_keep]
-        xt /= xt_norm[xt_to_keep, None]
-
-        if x0sym is None:
-            xt = _symmetric_orth(xt)
-        else:
-            xt_ir = xt_ir[xt_to_keep]
-            xt_orth = []
-            xt_orth_ir = []
-            for ir in set(xt_ir):
-                idx = np.where(xt_ir == ir)[0]
-                xt_sub = _symmetric_orth(xt[idx])
-                xt_orth.append(xt_sub)
-                xt_orth_ir.append([ir] * len(xt_sub))
-            if xt_orth:
-                xt = np.vstack(xt_orth)
-                xs_ir = np.hstack([xs_ir, *xt_orth_ir])
+        if len(xt) > 0:
+            xt /= xt_norm[xt_to_keep, None]
+            if x0sym is None:
+                xt = _symmetric_orth(xt)
             else:
-                xt = []
-            xt_orth = xt_orth_ir = xt_sub = None
+                xt_ir = xt_ir[xt_to_keep]
+                xt_orth = []
+                xt_orth_ir = []
+                for ir in set(xt_ir):
+                    idx = np.where(xt_ir == ir)[0]
+                    xt_sub = _symmetric_orth(xt[idx])
+                    xt_orth.append(xt_sub)
+                    xt_orth_ir.append([ir] * len(xt_sub))
+                if xt_orth:
+                    xt = np.vstack(xt_orth)
+                    xs_ir = np.hstack([xs_ir, *xt_orth_ir])
+                else:
+                    xt = []
+                xt_orth = xt_orth_ir = xt_sub = None
 
         if len(xt) == 0:
             log.debug(f'Linear dependency in trial subspace. |r| for each state {dx_norm}')