Singularity and Coulomb integrals
Implementation of the Coulomb singularity for the Coulomb integrals in solids. This goes along with some change and improvement of the Poisson solver for FFTs, to support these changes. A large potion of the code comes from the branch for hybrids with k-points, and this branch is therefore a first step toward merging the branch into develop.
Implementation of the Coulomb singularity for the Coulomb integrals in solids.
- I have checked that my code follows the Octopus coding standards
- I have added tests for all the new features added in this request.