Skip to content

Database

mdinterface ships a built-in database of common species with pre-defined force-field parameters. All entries are importable from mdinterface.database.

Metals

from mdinterface.database import Metal111

gold    = Metal111("Au")
silver  = Metal111("Ag")
platinum = Metal111("Pt")
copper  = Metal111("Cu")

Metal111 generates an FCC (111) surface slab. The element symbol selects the lattice parameter and Lennard-Jones parameters.

Water models

from mdinterface.database import Water

water_spce  = Water(model="ewald") # modified tip3p model
water_tip4p = Water(model="spce")  # SPC/E water

Ions

from mdinterface.database import Ion

na = Ion("Na", ffield="Cheatham")
cl = Ion("Cl", ffield="Cheatham")
li = Ion("Li", ffield="Cheatham")
k  = Ion("K",  ffield="Cheatham")

Currently, the following force field parameters for monovalent ions have been implemented:

Special ion species also available:

from mdinterface.database import Perchlorate, Hydronium, Hydroxide

If the parameter set you are looking for are not present, you can always create a Specie explicitly:

from mdinterface import Specie

Li = Specie("Li", charges=1, lj={"Li": [0.33673, 1.40940]})

Noble gases

from mdinterface.database import Neon, Argon, Krypton, Xenon, NobleGas

ar = Argon()
xe = Xenon()
# or generically:
gas = NobleGas("Kr")

Graphene

from mdinterface.database import Graphene

grap = Graphene()

Small molecules

from mdinterface.database import Oxygen, Hydrogen, Nitrogen