Libcint

Integral Driver: Libcint

libcint-based integral implementations.

Drivers

Driver: Libcint

Base class for a libcint-based integral implementation Calculation and modification of multipole integrals.

class dxtb._src.integral.driver.libcint.driver.BaseIntDriverLibcint(*args, **kwargs)

Bases: LibcintImplementation, IntDriver

Implementation of libcint-based integral driver.

setup(positions, **kwargs)

Run the libcint-specific driver setup.

Return type:

None

Parameters:

positions (Tensor) – Cartesian coordinates of all atoms (shape: (..., nat, 3)).

Parameters:

positions (Tensor)

family: Literal['libcint']

Label for integral implementation family.

ihelp: IndexHelper

Helper class for indexing.

numbers: Tensor

Atomic numbers of the atoms in the system.

par: ParamModule

Representation of parametrization of xTB method.

class dxtb._src.integral.driver.libcint.driver.IntDriverLibcint(*args, **kwargs)

Bases: BaseIntDriverLibcint

Implementation of libcint-based integral driver.

family: Literal['libcint']

Label for integral implementation family.

ihelp: IndexHelper

Helper class for indexing.

numbers: Tensor

Atomic numbers of the atoms in the system.

par: ParamModule

Representation of parametrization of xTB method.

Implementations

Implementation: Overlap

Overlap implementation based on libcint.

class dxtb._src.integral.driver.libcint.overlap.OverlapLibcint(device=None, dtype=None, uplo='l', cutoff=50.0)

Bases: OverlapIntegral, IntegralLibcint

Overlap integral from atomic orbitals.

Use the build() method to calculate the overlap integral. The returned matrix uses a custom autograd function to calculate the backward pass with the analytical gradient. For the full gradient, i.e., a matrix of shape (..., norb, norb, 3), the get_gradient() method should be used.

Parameters:

• device (torch.device | None)

• dtype (torch.dtype | None)

• uplo (Literal['n', 'u', 'l'])

• cutoff (Tensor | float | int | None)

build(driver, **_)

Calculation of overlap integral using libcint.

Return type:

Tensor

Returns:

driver – The integral driver for the calculation.

Return type:

IntDriverLibcint

Returns:

Overlap integral matrix of shape (..., norb, norb).

Return type:

Tensor

Parameters:

• driver (IntDriverLibcint)

• _ (Any)

get_gradient(driver, **_)

Overlap gradient calculation using libcint.

Return type:

Tensor

Parameters:

driver (IntDriverLibcint) – The integral driver for the calculation.

Returns:

Overlap gradient of shape (..., norb, norb, 3).

Return type:

Tensor

Parameters:

• driver (IntDriverLibcint)

• _ (Any)

cutoff: Tensor | float | int | None

Real-space cutoff for integral calculation in Bohr. Defaults to constants.defaults.INTCUTOFF.

family: Literal['libcint']

Label for integral implementation family.

uplo: Literal['n', 'u', 'l']

Whether the matrix of unique shell pairs should be create as a triangular matrix (l: lower, u: upper) or full matrix (n). Defaults to l (lower triangular matrix).

Implementation: Multipole Base

Template for calculation and modification of multipole integrals.

class dxtb._src.integral.driver.libcint.multipole.MultipoleLibcint(device=None, dtype=None, uplo='l', cutoff=50.0)

Bases: IntegralLibcint

Base class for multipole integrals calculated with libcint.

Parameters:

• device (torch.device | None)

• dtype (torch.dtype | None)

• uplo (Literal['n', 'u', 'l'])

• cutoff (Tensor | float | int | None)

multipole(driver, intstring)

Calculation of multipole integral. The integral is normalized, using the diagonal of the overlap integral.

Return type:

Tensor

Parameters:

• driver (IntDriver) – The integral driver for the calculation.

• intstring (str) – String for libcint integral engine.

Returns:

Normalized multipole integral.

Return type:

Tensor

Parameters:

• driver (IntDriverLibcint)

• intstring (str)

cutoff: Tensor | float | int | None

Real-space cutoff for integral calculation in Bohr. Defaults to constants.defaults.INTCUTOFF.

family: Literal['libcint']

Label for integral implementation family.

uplo: Literal['n', 'u', 'l']

Whether the matrix of unique shell pairs should be create as a triangular matrix (l: lower, u: upper) or full matrix (n). Defaults to l (lower triangular matrix).

Implementation: Dipole

Dipole integral implementation based on libcint.

class dxtb._src.integral.driver.libcint.dipole.DipoleLibcint(device=None, dtype=None, uplo='l', cutoff=50.0)

Bases: DipoleIntegral, MultipoleLibcint

Dipole integral from atomic orbitals.

Parameters:

• device (torch.device | None)

• dtype (torch.dtype | None)

• uplo (Literal['n', 'N', 'u', 'U', 'l', 'L'])

• cutoff (Tensor | float | int | None)

build(driver)

Calculation of dipole integral using libcint.

Return type:

Tensor

Parameters:

driver (IntDriverLibcint) – The integral driver for the calculation.

Returns:

Dipole integral.

Return type:

Tensor

Parameters:

driver (IntDriverLibcint)

get_gradient(driver)

Calculation of dipole gradient using libcint.

Return type:

Tensor

Parameters:

driver (IntDriverLibcint) – The integral driver for the calculation.

Returns:

Dipole gradient.

Return type:

Tensor

Parameters:

driver (IntDriverLibcint)

cutoff: Tensor | float | int | None

Real-space cutoff for integral calculation in Bohr. Defaults to constants.defaults.INTCUTOFF.

family: Literal['libcint']

Label for integral implementation family.

uplo: Literal['n', 'u', 'l']

Whether the matrix of unique shell pairs should be create as a triangular matrix (l: lower, u: upper) or full matrix (n). Defaults to l (lower triangular matrix).

Implementation: Quadrupole

Quadrupole integral implementation based on libcint.

class dxtb._src.integral.driver.libcint.quadrupole.QuadrupoleLibcint(device=None, dtype=None, uplo='l', cutoff=50.0)

Bases: QuadrupoleIntegral, MultipoleLibcint

Quadrupole integral from atomic orbitals.

Parameters:

• device (torch.device | None)

• dtype (torch.dtype | None)

• uplo (Literal['n', 'N', 'u', 'U', 'l', 'L'])

• cutoff (Tensor | float | int | None)

build(driver)

Calculation of quadrupole integral using libcint.

Return type:

Tensor

Parameters:

driver (IntDriverLibcint) – The integral driver for the calculation.

Returns:

Quadrupole integral.

Return type:

Tensor

Parameters:

driver (IntDriverLibcint)

get_gradient(driver, **kwargs)

Calculation of quadrupole gradient using libcint.

Return type:

Tensor

Parameters:

driver (IntDriverLibcint) – The integral driver for the calculation.

Returns:

Quadrupole gradient.

Return type:

Tensor

Parameters:

• driver (IntDriver)

• kwargs (Any)

cutoff: Tensor | float | int | None

Real-space cutoff for integral calculation in Bohr. Defaults to constants.defaults.INTCUTOFF.

family: Literal['libcint']

Label for integral implementation family.

uplo: Literal['n', 'u', 'l']

Whether the matrix of unique shell pairs should be create as a triangular matrix (l: lower, u: upper) or full matrix (n). Defaults to l (lower triangular matrix).