Chen Nuo

Now that `HSolver` module is undergoing a massive refactoring, and there is a lack of systematic testing for generalized eigenvalue problems on iterative diagonalization methods, this issue will be suspended...

@pxlxingliang Is abacus test result now accessible to public? I try to look into the examples offered in https://labs.dp.tech/projects/abacustest/?request=GET%3A%2Fapplications%2Fabacustest%2Fjobs%2Fjob-abacustest-v0.3.74-7cf445 but it seems I am refused to check the results. Messages...

@pxlxingliang Thank you! Now I have access to these examples via the new link.

After investigating math of Davidson, we find duplicate function of overlap matrix `scc` and orthogonalization. #4874 removes useless scc of origin Davidson method. #3903 adds a new Davidson iteration method...