Added tip5pe water model to oplsa.

The model introduces a small modification to the tip5p model
to reproduce better experimental data for simulations using
Ewald summation.

Reference publication J. Chem. Phys. 120 (2004) 6085-6093.

Fixes #1016.

Change-Id: I1afba614d65d1e4e8eb8594e99eea41e31f1e391

diff --git a/share/top/oplsaa.ff/ffnonbonded.itp b/share/top/oplsaa.ff/ffnonbonded.itp
index cfc48092c01ca31daced31bf4de223009d47be0b..5d5f0bfaa49e01dcb356aabe46effa40058f7d5f 100644 (file)
--- a/share/top/oplsaa.ff/ffnonbonded.itp
+++ b/share/top/oplsaa.ff/ffnonbonded.itp
@@ -128,6 +128,7 @@
  opls_117   HW 1      1.00800     0.410       A    0.00000e+00  0.00000e+00
 #endif
  opls_118   OW 8     15.99940     0.000       A    3.12000e-01  6.69440e-01
+ opls_118e  OW  8     15.99940     0.000       A    3.09700e-01  7.44752e-01 ; J. Chem. Phys. 120 (2004) 6085-6093
  opls_119   HW 1      1.00800     0.000       A    0.00000e+00  0.00000e+00
  opls_120   OL 0      0.00000     0.000       D    0.00000e+00  0.00000e+00
  opls_122   CT 6     12.01100     0.248       A    3.80000e-01  2.09200e-01

diff --git a/share/top/oplsaa.ff/tip5pe.itp b/share/top/oplsaa.ff/tip5pe.itp
new file mode 100644 (file)
index 0000000..2801439
--- /dev/null
+++ b/share/top/oplsaa.ff/tip5pe.itp
@@ -0,0 +1,38 @@
+[ moleculetype ]
+; molname       nrexcl
+SOL             2
+
+[ atoms ]
+; id    at type res nr  residu name     at name         cg nr   charge
+1       opls_118e    1       SOL              OW             1       0
+2       opls_119     1       SOL             HW1             1       0.241
+3       opls_119     1       SOL             HW2             1       0.241
+4       opls_120     1       SOL             LP1             1      -0.241
+5       opls_120     1       SOL             LP2             1      -0.241
+
+[ settles ]
+; i     funct   doh     dhh
+1       1       0.09572 0.15139
+
+[ virtual_sites3 ]
+; The position of the virtual site is computed as follows:
+;
+; The distance from OW to L is 0.07 nm, the geometry is tetrahedral
+; (109.47 deg)
+; Therefore, a = b = 0.07 * cos (109.47/2) / | xOH1 + xOH2 |
+;            c = 0.07 * sin (109.47/2) / | xOH1 X xOH2 |
+;
+; Using | xOH1 X xOH2 | = | xOH1 | | xOH2 | sin (H1-O-H2)
+;       | xOH1 + xOH2 | = 2 | xOH1 | cos (H1-O-H2)
+; Vsite pos x4 = x1 + a*x21 + b*x31 + c*(x21 X x31)
+
+; Vsite from                    funct   a       b               c
+4       1       2       3       4       -0.344908  -0.344908  -6.4437903493
+5       1       2       3       4       -0.344908  -0.344908   6.4437903493
+
+[ exclusions ]
+1       2       3       4       5
+2       1       3       4       5
+3       1       2       4       5
+4       1       2       3       5
+5       1       2       3       4

diff --git a/share/top/oplsaa.ff/watermodels.dat b/share/top/oplsaa.ff/watermodels.dat
index 513bcae0d6222a9e18396176f495b23dde4400b3..44f5e9270a7602129556ac13a010a99016551c58 100644 (file)
--- a/share/top/oplsaa.ff/watermodels.dat
+++ b/share/top/oplsaa.ff/watermodels.dat
@@ -1,5 +1,6 @@
 tip4p   TIP4P  TIP 4-point, recommended
 tip3p   TIP3P  TIP 3-point
 tip5p   TIP5P  TIP 5-point
+tip5pe  TIP5P  TIP 5-point improved for Ewald sums
 spc     SPC    simple point charge
 spce    SPC/E  extended simple point charge