Other built-in calculators

TIP3P

class ase.calculators.tip3p.TIP3P(rc=5.0, width=1.0)[source]

TIP3P potential.

rc: float
Cutoff radius for Coulomb part.
width: float
Width for cutoff function for Coulomb part.

TIP4P

class ase.calculators.tip4p.TIP4P(rc=7.0, width=1.0)[source]

TIP4P potential for water.

http://dx.doi.org/10.1063/1.445869

Requires an atoms object of OHH,OHH, … sequence Correct TIP4P charges and LJ parameters set automatically.

Virtual interaction sites implemented in the following scheme: Original atoms object has no virtual sites. When energy/forces are requested:

  • virtual sites added to temporary xatoms object
  • energy / forces calculated
  • forces redistributed from virtual sites to actual atoms object

This means you do not get into trouble when propagating your system with MD while having to skip / account for massless virtual sites.

This also means that if using for QM/MM MD with GPAW, the EmbedTIP4P class must be used.

Lennard-Jones

class ase.calculators.lj.LennardJones(**kwargs)[source]

Morse

class ase.calculators.morse.MorsePotential(**kwargs)[source]

Morse potential.

Default values chosen to be similar as Lennard-Jones.