File Local2c2eIntegralCalculator.h¶

Copyright

This code is licensed under the 3-clause BSD license.

Copyright ETH Zurich, Laboratory for Physical Chemistry, Reiher Group.

See LICENSE.txt for details.

namespace Scine

namespace Sparrow

namespace nddo

namespace multipole

class Local2c2eIntegralCalculator

#include <Local2c2eIntegralCalculator.h>

This class is responsible for the calculation of the 2-center-2-electron integrals in the local coordinate system.

Public Types

using LocalTerms = std::list<LocalTerm>: Each charge distribution might be expanded in more than just one multipole (so, more than one LocalTerm possible).

using LocalTermArray = std::array<std::array<LocalTerms, 40>, 40>: There are 40 possible charge distributions.

Public Static Functions

template<Utils::derivOrder O> static Utils::AutomaticDifferentiation::Value1DType<O> getIntegral(GeneralTypes::twoElIntegral_t t1, GeneralTypes::twoElIntegral_t t2, double R, const ChargeSeparationParameter &D1, const ChargeSeparationParameter &d2, const KlopmanParameter &rho1, const KlopmanParameter &rho2): Wrapper around the next overload. It enables the reference of the twoElIntegral_t without the need to cast them.

Calculates the integral value (up to the derivative order O) of the repulsion integral.

Return

The 2-center-2-electron value up to the O-th derivative in the local coordinates system.

Template Parameters

O: the derivative order, defines up to which derivative the value must be computed.

Parameters

t1: the index referring to the first GeneralTypes::twoElIntegral_t orbital pair.
t2: the index referring to the second GeneralTypes::twoElIntegral_t orbital pair.
R: the distance between the two centers at which the multipoles are located.
D1: the charge separation parameter belonging to the first multipole.
d2: the charge separation parameter belonging to the second multipole.
rho1: the Klopman parameter for the first center.
rho2: the Klopman parameter for the second center.

Private Static Functions

static LocalTermArray setUpTerms()¶: Generates the possible terms that define the multipole/multipole interactions.

static std::list<std::pair<double, multipole_t>> getMultipoles(GeneralTypes::twoElIntegral_t t, bool hasD)¶

Generates a multipole corresponding to the two electron integral type t.

hasD makes sure that charge configuration corresponding to different multipoles in presence or absence of d basis functions are correctly represented

struct LocalTerm

#include <Local2c2eIntegralCalculator.h>

Struct defining an interaction between two multipoles.

It consists of a prefactor, f, the charge distributions and the corresponding multipoles. It thus uniquely defines an interaction.

Public Members