This is the first release of ELSI-RCI. The ELSI-RCI implements reverse communication interfaces for several iterative eigensolvers, including Davidson, OMM, PPCG, and ChebFilter.

In the simple test provided, OMM, ChebFilter are far from convergence due to small iteration numbers. Again, the performance of these two methods are sensitive to their hyper-parameters related to spectrum range of the given matrix.