OpenMM tip4p

tip4p.xml

<ForceField>
 <Info>
  <Reference>Lee-Ping Wang, Todd J. Martinez and Vijay S. Pande. Building force fields - an automatic, systematic and reproducible approach.  Journal of Physical Chemistry Letters, ASAP, 2014. DOI: 10.1021/jz500737m.</Reference>
 </Info>
 <AtomTypes>
  <Type name="tip4p-fb-O" class="OW" element="O" mass="15.99943"/>
  <Type name="tip4p-fb-H" class="HW" element="H" mass="1.007947"/>
  <Type name="tip4p-fb-M" class="MW" mass="0"/>
 </AtomTypes>
 <Residues>
  <Residue name="HOH">
   <Atom name="O" type="tip4p-fb-O"/>
   <Atom name="H1" type="tip4p-fb-H"/>
   <Atom name="H2" type="tip4p-fb-H"/>
   <Atom name="M" type="tip4p-fb-M"/>
   <VirtualSite type="average3" index="3" atom1="0" atom2="1" atom3="2" weight1="8.203146574531e-01" weight2="8.984267127345e-02" weight3="8.984267127345e-02" />
   <Bond from="0" to="1"/>
   <Bond from="0" to="2"/>
  </Residue>
 </Residues>
 <HarmonicBondForce>
  <Bond class1="OW" class2="HW" length="0.09572" k="462750.4"/>
 </HarmonicBondForce>
 <HarmonicAngleForce>
  <Angle class1="HW" class2="OW" class3="HW" angle="1.82421813418" k="836.8"/>
 </HarmonicAngleForce>
 <NonbondedForce coulomb14scale="0.5" lj14scale="0.5">
  <Atom type="tip4p-fb-O" charge="0" sigma="3.165552430462e-01" epsilon="7.492790213533e-01" />
  <Atom type="tip4p-fb-H" charge="5.258681106763e-01" sigma="1" epsilon="0" />
  <Atom type="tip4p-fb-M" charge="-1.0517362213526e+00" sigma="1" epsilon="0" />
 </NonbondedForce>
</ForceField>