ExpHP / rsp2

phonons in rust
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results after relaxation along modes from the sparse eigensolver are highly nondeterministic #72

Open ExpHP opened 6 years ago

ExpHP commented 6 years ago

Some small amount of numerical variations are to be expected from parallel load distribution, but the sparse-gnr integration test requires unreasonably large floating point tolerances to have any chance of succeeding. I believe this is because eigsh uses a random starting vector, which has a butterfly effect after relaxation along the negative modes.