Source code for dxtb._src.param.thirdorder

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"""
Parametrization: Electrostatics (3rd order)
===========================================

Definition of the isotropic third-order onsite correction.
"""

from __future__ import annotations

from typing import Literal, Union

from pydantic import BaseModel

__all__ = ["ThirdOrderShell", "ThirdOrder"]




class ThirdOrderShell(BaseModel):
    """Representation of shell-resolved third-order electrostatics."""

    s: float
    """Scaling factor for s-orbitals."""

    p: float
    """Scaling factor for p-orbitals."""

    d: float
    """Scaling factor for d-orbitals."""





class ThirdOrder(BaseModel):
    """
    Representation of the isotropic third-order onsite correction.
    """

    shell: Union[Literal[False], ThirdOrderShell] = False
    """
    Whether the third order contribution is shell-dependent or only atomwise.
    """