From 6581233c54e22ac174e2c2f9b995b4b02ce7ca03 Mon Sep 17 00:00:00 2001
From: keitaroyam <keitaroyam@users.noreply.github.com>
Date: Mon, 11 Dec 2023 23:19:50 +0900
Subject: [PATCH] chiral_abs_volume: avoid nan

Chiral volume may become NaN in come cases. An example is the current PRO's chir_2, which will be fixed by https://github.com/MonomerLibrary/monomers/pull/38
---
 include/gemmi/chemcomp.hpp | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/gemmi/chemcomp.hpp b/include/gemmi/chemcomp.hpp
index f831666b..06c87656 100644
--- a/include/gemmi/chemcomp.hpp
+++ b/include/gemmi/chemcomp.hpp
@@ -311,7 +311,7 @@ inline double chiral_abs_volume(double bond1, double bond2, double bond3,
     x -= cosine * cosine;
     y *= cosine;
   }
-  return mult * std::sqrt(x + y);
+  return mult * std::sqrt(std::max(0., x + y));
 }
 
 inline double Restraints::chiral_abs_volume(const Restraints::Chirality& ch) const {