# field

Add a static external field to the Hamiltonian. This command can appear in the global context.

### Options

component

Component of the applied operator. For example

dft(
structure(formula = HF bond_length = 1 angstrom)
ao = DZP
xc = PBE
field(
operator = electric_dipole
component = z
strength = 0.02
)
)

applies a dipole electric field in the z direction.

This option is mandatory.

• The type is string
• There is no default value.
operator

Operator that describes the type of external field.

This option is mandatory.

• The type is string
• There is no default value.
• The value must be one of:
strength

Field strength in atomic units.

This option is mandatory.

• The type is real
• There is no default value.