Improved pseudopotential filtering
Improve the pseudopotential filtering by forcing the resulting density to be positive. This is mandatory for using VdW TS with filtering (due to a multiplication by r^3), and is better in general. The density derivative is now also filtered. In some cases, a LCAO failure could happen:
- In zgeneigensolve, LAPACKzhegv returned error message 31
- 31 off-diagonal elements of an intermediate tridiagonal did not converge to zero. In some cases this seems to be solved by the present fix.
However, this does not solve the fact that some mGGA calculation do not converge when the pseudopotential filtering is activated.
Improved pseudopotential filtering.
- I have checked that my code follows the Octopus coding standards
- I have added tests for all the new features added in this request.