forcefield section

The forcefield section selects the static and dynamic force field models used in atomistic simulations. This section is mandatory when running atomistic models (i.e. not BEM).

Valid keywords

Keyword

Type

Allowed Values

Default

static

string

fq, fqfmu

–

dynamic

string

wfq, wfqfmu

–

kernel

string

ohno, gaussian, coulomb

–

Notes

In the forcefield section, the default values are flexible and depends on the user selected keywords.

  • static selects the model for the static force field:

    • fq : fluctuating charges force field [default if dynamic: wfq]

    • fqfmu : fluctuating charges and fluctuating dipoles force field [default if dynamic: wfqfmu]

  • dynamic selects the model for the frequency-dependent response:

    • wfq: frequency-dependent fluctuating charges [currently available for sodium and carbon-based materials]

    • wfqfmu: frequency-dependent fluctuating charges and fluctuating dipoles [currently available for silver and gold]

  • kernel defines the electrostatic interaction model between atomistic sites:

    • coulomb: pure Coulomb interaction [not recommended]

    • ohno: Ohno kernel [default if static: fq]

    • gaussian: Gaussian kernel [default if static: fq or dynamic: wfq or dynamic: wfqfmu]

Example

forcefield:
  static: fqfmu
  dynamic: wfqfmu
  kernel: gaussian