[gmx-developers] possible OPLS-aa implementation bug?

[Alan Chen]

I noticed in ffoplsaa.rtp (in the released 3.2.1 code) that for Cysteine 
the assigned charges are
from Jorgensen 2001 while the Methionine charges do not reflect the 2001 
revisions but still use
the Jorgensen 1996 parameters.   Specifically opls_202 should be -0.335 
while types 209 and 210
should be decreased by -0.05e.

Hope this is useful to someone

Cheers,
Alan Chen


[ MET ]
  [ atoms ]
      N    opls_238   -0.500     1
      H    opls_241    0.300     1
     CA    opls_224B   0.140     1
     HA    opls_140    0.060     1
     CB    opls_136   -0.120     2
    HB1    opls_140    0.060     2
    HB2    opls_140    0.060     2
     CG    opls_210    0.0975    3
    HG1    opls_140    0.060     3
    HG2    opls_140    0.060     3
     SD    opls_202   -0.435     4
     CE    opls_209    0.0375    5
    HE1    opls_140    0.060     5
    HE2    opls_140    0.060     5
    HE3    opls_140    0.060     5
      C    opls_235    0.500     6
      O    opls_236   -0.500     6