Use correct c0 parameter in Me2PO4 in OPLSAA

Fixes #4075

diff --git a/docs/release-notes/2022/major/bugs-fixed.rst b/docs/release-notes/2022/major/bugs-fixed.rst
index 510658b250fdec3902a5aa6eec6375becababd18..c41151c576e07ec3d314e23c38717787ae249968 100644 (file)
--- a/docs/release-notes/2022/major/bugs-fixed.rst
+++ b/docs/release-notes/2022/major/bugs-fixed.rst
@@ -26,3 +26,11 @@ both dhdl.xvg and the energy file, which is used by e.g. gmx bar, was correct.
    Also, please use the syntax :issue:`number` to reference issues on GitLab, without the
    a space between the colon and number!
 
+Use correct c0 parameter in Me2PO4 in OPLSAA
+""""""""""""""""""""""""""""""""""""""""""""
+
+OPLSAA torsions must sum to 0, but the paramters for Me2PO4 did not do so. Changed the c0
+parameter to the correct value.
+
+:issue:`4075`
+

diff --git a/share/top/oplsaa.ff/ffbonded.itp b/share/top/oplsaa.ff/ffbonded.itp
index bcd643608e4cfae5e1c15ef083ab3c3d0749d6ff..944e9c82913333def13ab6b17a7bb5d8248016fc 100644 (file)
--- a/share/top/oplsaa.ff/ffbonded.itp
+++ b/share/top/oplsaa.ff/ffbonded.itp
@@ -1666,7 +1666,7 @@
   CT     OS     C      HC      3     31.20637  -9.76754 -21.43881   0.00000   0.00000   0.00000 ; esters
   CT     OS     P      CT      3     -3.34720   2.09200  13.80720 -12.55200   0.00000   0.00000 ; phosphonates
   CT     OS     P      O2      3      1.17570   3.52711   0.00000  -4.70281   0.00000   0.00000 ; Me2PO4 (-)
-  CT     OS     P      OS      3      1.04600   3.13800  10.04160  -4.18400   0.00000   0.00000 ; Me2PO4 (-), from Amber.
+  CT     OS     P      OS      3      -8.9956   3.13800  10.04160  -4.18400   0.00000   0.00000 ; Me2PO4 (-), from Amber.
   CT     OS     CM     HC      3      1.58992   4.76976   0.00000  -6.35968   0.00000   0.00000 ; ethers AA
   CT     OS     CO     HC      3      1.58992   4.76976   0.00000  -6.35968   0.00000   0.00000 ; ethers AA
   CT     OS     CO     OH      3     -6.45801   0.80961   5.68187  -0.03347   0.00000   0.00000 ; hexopyranoses