From 6891230ffab961eab5bd2406945efd1d76de2b41 Mon Sep 17 00:00:00 2001
From: WHOIM1205 <your-email@users.noreply.github.com>
Date: Tue, 17 Mar 2026 15:31:06 -0700
Subject: [PATCH] Fix AttributeError when Hessian has no negative eigenvalues

Signed-off-by: WHOIM1205 <rathourprateek8@gmail.com>
---
 ffprime/bond.py | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/ffprime/bond.py b/ffprime/bond.py
index cf4ef0c..5082803 100644
--- a/ffprime/bond.py
+++ b/ffprime/bond.py
@@ -28,6 +28,8 @@ def __init__(self, log_path="bonding/lig.log", fchk_path="bonding/lig.fchk"):
                 print("Eigenvectors are orthonormal.")
             else:
                 raise ValueError("Eigenvectors are not orthonormal.")
+        else:
+            self.hess_new = self.hess.copy()
 
         self.hess_new = (self.hess_new * 627.509391) / (0.529 ** 2)
         self.hess = (self.hess * 627.509391) / (0.529 ** 2)