A handful of forcefields ready-formatted for import into Aten are provided with the code and are listed here. It should be a relatively straightforward process to convert others, unless the functional forms used are not yet implemented (but sure, if you ask then I will add them). If you export an expression from Aten, please check the parameters in the file are what you actually want. Aten is designed to ease the pain of setting up a simulation in this manner, but is not intended as a black box.

Canongia-Lopes & Padua Ionic Liquids (cldp-il.ff)

All-atom ionic liquids forcefield of Canongia Lopes et al. covering various cation/anion combinations.

References:

  • J. N. Canongia Lopes, A. A. H. Padua, J. Phys. Chem. B, 110 (39), 19586-19592 (2006)
  • J. N. Canongia Lopes, A. A. H. Padua, J. Phys. Chem. B, 108 (43), 16893-16898 (2004)
  • J. N. Canongia Lopes, J. Deschamps, A. A. H. Padua, J. Phys. Chem. B, 108 (30), 11250 (2004)
  • J. N. Canongia Lopes, J. Deschamps, A. A. H. Padua, J. Phys. Chem. B, 108 (6), 2038-2047 (2004)

Youngs, Kohanoff, & Del Pópolo [dmim]Cl (dmimcl-fm.ff)

Force-matched model for the ionic liquid dimethylimidazolium chloride only. Integer charges on ions.

References:

  • T. G. A. Youngs, J. Kohanoff, and M. G. Del Pópolo, J. Phys. Chem. B, 110 (11), 5697-5707 (2006)

Youngs & Hardacre [dmim]Cl (dmimcl-fm2.ff)

Second force-matched model for the ionic liquid dimethylimidazolium chloride only. Non-integer charges on ions.

References:

  • T. G. A. Youngs and C. Hardacre, ChemPhysChem, 9 (11), 1548-1558 (2008)

Jorgensen at al. OPLS-AA (oplsaa.ff)

Original OPLS-AA forcefield of Jorgensen et al. Thanks to W. Jorgensen for supplying the parameter data.

References:

  • W. L. Jorgensen, D. S. Maxwell, and J. Tirado-Rives, J. Am. Chem. Soc. 118, 11225-11236 (1996).
  • W. L. Jorgensen and N. A. McDonald, Theochem 424, 145-155 (1998).
  • W. L. Jorgensen and N. A. McDonald, J. Phys. Chem. B 102, 8049-8059 (1998).
  • R. C. Rizzo and W. L. Jorgensen, J. Am. Chem. Soc. 121, 4827-4836 (1999).
  • M. L. Price, D. Ostrovsky, and W. L. Jorgensen, J. Comp. Chem. 22 (13), 1340-1352 (2001).
  • E. K. Watkins and W. L. Jorgensen, J. Phys. Chem. A 105, 4118-4125 (2001).

Note: NETA definitions have been written for a large number of types in the forcefield, but not all.

Berendsen et al. Simple Point Charge Water (spc.ff)

Rigid, simple point charge model for water

References:

  • H. J. C. Berendsen, J. P. M. Postma, W. F. van Gunsteren and J. Hermans, in Intermolecular Forces, B. Pullman (ed.), Reidel, Dordrecht, 1981, p331.

Berendsen et al. Extended Simple Point Charge Water (spce.ff)

Simple point charge model for water, modified to reproduce molecular dipole in the liquid phase.

References:

  • J. C. Berendsen, J. R. Grigera and T. P. Straatsma, J. Phys. Chem. 91, 6269-6271 (1987)

Rappe et al. Universal Forcefield (uff.ff)

Universal forcefield for the whole periodic table by Rappe et al.

References:

  • A. K. Rappe, C. J. Casewit, K. S. Colwell, W. A. Goddard III, and W. M. Skiff, J. Am. Chem. Soc. 114, 10024-10039 (1992)

Notes:

  • Generated terms should be checked by hand if forcefield expressions are exported.
  • Detection of some atomtypes, namely transition metals, is imperfect.
  • Warning: Generation of terms (especially angles) needs to undergo proper testing! If you wish to help, please contact me.

Mayo, Olafson & Goddard II's Generic Forcefield (testing/dreiding.ff)

Universal forcefield for the whole periodic table.

References:

  • S.L. Mayo, B.D. Olafson, and W.A. Goddard III, J. Phys. Chem. 94, 8897-8909 (1990).

Notes:

  • dreiding.ff currently lives in the testing/ directory since it is a rule-based forcefield and is currently being rewritten.
  • Generated terms should be checked by hand if forcefield expressions are exported.
  • Detection of some atomtypes, namely transition metals, is imperfect.
  • Warning: Generation of terms (especially angles) needs to undergo proper testing! If you wish to help, please contact me.

General Amber Forcefield (testing/gaff.ff)

General Amber forcefield containing precalculated data for most intramolecular terms, and a generator section for any that are missing.

References:

  • J. Wang, R. M. Wolf, J. W. Caldwell, P. A. Kollman, and D. A. Case, J. Comp. Chem. 25, 1157-1174 (2004)

Notes:

  • gaff.ff currently lives in the testing/ directory since it's rule-based part has not been implemented yet.

Liu, Wu & Wang's United-Atom Ionic Liquids Forcefield (lww-il.ff)

United atom ionic liquids forcefield for a handful of cations and anions.

References:

  • X. Zhang, F. Huo, Z. Liu, W. Wang, W. Shi, and E. J. Maginn, J. Phys. Chem. B 113, 7591-7598 (2009)
  • Z. Liu, X. Wu, and W. Wang, Phys. Chem. Chem. Phys. 8, 1096-1104 (2006)