Source code for dxtb._src.integral.driver.libcint.quadrupole

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# SPDX-Identifier: Apache-2.0
# Copyright (C) 2024 Grimme Group
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"""
Implementation: Quadrupole
==========================

Quadrupole integral implementation based on `libcint`.
"""

from __future__ import annotations

from dxtb._src.integral.base import IntDriver
from dxtb._src.typing import Any, Tensor

from ...types import QuadrupoleIntegral
from .driver import IntDriverLibcint
from .multipole import MultipoleLibcint

__all__ = ["QuadrupoleLibcint"]




class QuadrupoleLibcint(QuadrupoleIntegral, MultipoleLibcint):
    """
    Quadrupole integral from atomic orbitals.
    """



    def build(self, driver: IntDriverLibcint) -> Tensor:
        """
        Calculation of quadrupole integral using libcint.

        Parameters
        ----------
        driver : IntDriverLibcint
            The integral driver for the calculation.

        Returns
        -------
        Tensor
            Quadrupole integral.
        """
        return self.multipole(driver, "r0r0")




    def get_gradient(self, driver: IntDriver, **kwargs: Any) -> Tensor:
        """
        Calculation of quadrupole gradient using libcint.

        Parameters
        ----------
        driver : IntDriverLibcint
            The integral driver for the calculation.

        Returns
        -------
        Tensor
            Quadrupole gradient.
        """
        raise NotImplementedError("Gradient calculation not implemented.")