From fbffcd3399afd154f2524265dbdbb265120301d3 Mon Sep 17 00:00:00 2001
From: victor <victor.vanthilt@gmail.com>
Date: Fri, 14 Feb 2025 17:23:41 +0100
Subject: [PATCH] implement the optimal contraction ordering for `BTRG`

---
 src/schemes/btrg.jl | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/src/schemes/btrg.jl b/src/schemes/btrg.jl
index a633e48..1e1c46f 100644
--- a/src/schemes/btrg.jl
+++ b/src/schemes/btrg.jl
@@ -54,11 +54,13 @@ function step!(scheme::BTRG, trunc::TensorKit.TruncationScheme)
     S1 = scheme.S1
     S2 = scheme.S2
 
-    @tensor opt = true scheme.T[-1 -2; -3 -4] := D[-1 1; 8] * S1[2; 1] * B[-2; 3 2] *
-                                                 S2[3; 4] *
-                                                 C[4; 5 -3] *
-                                                 S1[5; 6] * A[7 6; -4] * S2[8; 7]
-
+    @tensor scheme.T[-1 -2; -3 -4] := D[-1 7; 4] *
+                                      S1[1; 7] *
+                                      B[-2; 3 1] *
+                                      S2[3; 2] *
+                                      C[2; 8 -3] *
+                                      S1[8; 5] *
+                                      A[6 5; -4] * S2[4; 6]
     scheme.S1 = S1′
     scheme.S2 = S2′
     return scheme