<ForceField>
 <Info>
  <DateGenerated>2022-06-21</DateGenerated>
  <Reference>Izadi S, Onufriev AV. Accuracy limit of rigid 3-point water models. The Journal of Chemical Physics 145, 074501 (2016); DOI:10.1063/1.4960175</Reference>
 </Info>
 <AtomTypes>
  <Type name="opc3-O" class="OW" element="O" mass="16.00000"/>
  <Type name="opc3-H" class="HW" element="H" mass="1.00800"/>
 </AtomTypes>
 <Residues>
  <Residue name="HOH">
   <Atom name="O" type="opc3-O"/>
   <Atom name="H1" type="opc3-H"/>
   <Atom name="H2" type="opc3-H"/>
   <Bond atomName1="O" atomName2="H1"/>
   <Bond atomName1="O" atomName2="H2"/>
  </Residue>
 </Residues>
 <HarmonicBondForce>
  <Bond class1="OW" class2="HW" length="0.0978882" k="502416.0"/>
 </HarmonicBondForce>
 <HarmonicAngleForce>
  <!-- angle = arccos(1 - (1.598507**2 / (2*0.978882**2))) -->
  <Angle class1="HW" class2="OW" class3="HW" angle="1.9106321528999624" k="628.02"/>
 </HarmonicAngleForce>
 <NonbondedForce coulomb14scale="0.833333" lj14scale="0.5">
  <!-- sigma = (1.7814990 * 2 / (2**(1/6)))*unit.angstrom/unit.nanometer -->
  <!-- epsilon = (0.163406*unit.kilocalorie)/(unit.kilojoule) -->
  <Atom type="opc3-O" charge="-0.895170" sigma="0.31742703509365927" epsilon="0.683690704"/>
  <Atom type="opc3-H" charge="0.447585" sigma="1" epsilon="0"/>
 </NonbondedForce>
</ForceField>
