/*
* Copyright 2009-2020 The VOTCA Development Team
* (http://www.votca.org)
*
* Licensed under the Apache License, Version 2.0 (the "License")
*
* You may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
#pragma once
#ifndef VOTCA_XTP_ERIS_H
#define VOTCA_XTP_ERIS_H
// Local VOTCA includes
#include "threecenter.h"
namespace votca {
namespace xtp {
/**
* \brief Takes a density matrix and and an auxiliary basis set and calculates
* the electron repulsion integrals.
*
*/
class ERIs {
public:
void Initialize(const AOBasis& dftbasis, const AOBasis& auxbasis);
void Initialize_4c(const AOBasis& dftbasis);
Eigen::MatrixXd CalculateERIs_3c(const Eigen::MatrixXd& DMAT) const;
std::array<Eigen::MatrixXd, 2> CalculateERIs_EXX_3c(
const Eigen::MatrixXd& occMos, const Eigen::MatrixXd& DMAT) const {
std::array<Eigen::MatrixXd, 2> result;
result[0] = CalculateERIs_3c(DMAT);
if (occMos.rows() > 0 && occMos.cols() > 0) {
assert(occMos.rows() == DMAT.rows() && "occMos.rows()==DMAT.rows()");
result[1] = CalculateEXX_mos(occMos);
} else {
result[1] = CalculateEXX_dmat(DMAT);
}
return result;
}
Eigen::MatrixXd CalculateERIs_4c(const Eigen::MatrixXd& DMAT,
double error) const {
return Compute4c<false>(DMAT, error)[0];
}
std::array<Eigen::MatrixXd, 2> CalculateERIs_EXX_4c(
const Eigen::MatrixXd& DMAT, double error) const {
return Compute4c<true>(DMAT, error);
}
Index Removedfunctions() const { return _threecenter.Removedfunctions(); }
static double CalculateEnergy(const Eigen::MatrixXd& DMAT,
const Eigen::MatrixXd& matrix_operator) {
return matrix_operator.cwiseProduct(DMAT).sum();
}
private:
std::vector<libint2::Shell> basis_;
std::vector<Index> starts_;
std::vector<std::vector<Index>> shellpairs_;
std::vector<std::vector<libint2::ShellPair>> shellpairdata_;
Index maxnprim_;
Index maxL_;
Eigen::MatrixXd CalculateEXX_dmat(const Eigen::MatrixXd& DMAT) const;
Eigen::MatrixXd CalculateEXX_mos(const Eigen::MatrixXd& occMos) const;
std::vector<std::vector<libint2::ShellPair>> ComputeShellPairData(
const std::vector<libint2::Shell>& basis,
const std::vector<std::vector<Index>>& shellpairs) const;
Eigen::MatrixXd ComputeSchwarzShells(const AOBasis& dftbasis) const;
Eigen::MatrixXd ComputeShellBlockNorm(const Eigen::MatrixXd& dmat) const;
template <bool with_exchange>
std::array<Eigen::MatrixXd, 2> Compute4c(const Eigen::MatrixXd& dmat,
double error) const;
TCMatrix_dft _threecenter;
Eigen::MatrixXd schwarzscreen_; // Square matrix containing <ab|ab> for all
// shells
}; // namespace xtp
} // namespace xtp
} // namespace votca
#endif // VOTCA_XTP_ERIS_H