{"action":"created","issue":{"url":"https://api.github.com/repos/psi4/psi4/issues/298","repository_url":"https://api.github.com/repos/psi4/psi4","labels_url":"https://api.github.com/repos/psi4/psi4/issues/298/labels{/name}","comments_url":"https://api.github.com/repos/psi4/psi4/issues/298/comments","events_url":"https://api.github.com/repos/psi4/psi4/issues/298/events","html_url":"https://github.com/psi4/psi4/issues/298","id":137967089,"number":298,"title":"Numerical (?) noise in SCF gradient ","user":{"login":"psi-rking","id":3681868,"avatar_url":"https://avatars.githubusercontent.com/u/3681868?v=3","gravatar_id":"","url":"https://api.github.com/users/psi-rking","html_url":"https://github.com/psi-rking","followers_url":"https://api.github.com/users/psi-rking/followers","following_url":"https://api.github.com/users/psi-rking/following{/other_user}","gists_url":"https://api.github.com/users/psi-rking/gists{/gist_id}","starred_url":"https://api.github.com/users/psi-rking/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/psi-rking/subscriptions","organizations_url":"https://api.github.com/users/psi-rking/orgs","repos_url":"https://api.github.com/users/psi-rking/repos","events_url":"https://api.github.com/users/psi-rking/events{/privacy}","received_events_url":"https://api.github.com/users/psi-rking/received_events","type":"User","site_admin":false},"labels":[],"state":"open","locked":false,"assignee":null,"milestone":null,"comments":8,"created_at":"2016-03-02T19:24:31Z","updated_at":"2016-03-03T20:15:45Z","closed_at":null,"body":"Disilylether with scf_type=pk is fine.  Without it, the gradients are only c2v-symmetric to 9 decimal places, and after some geometry steps an optimization will fail due to change in point group.  Is this noise an inevitable consequence of density-fitting or some other approximation?  If so, can we symmetrize the gradient after it is produced?  I haven't confirmed this result yet with the very latest psi4.\r\n\r\n```python\r\nmemory 2 gb\r\nset {\r\n  basis 6-31G*\r\n  reference RHF\r\n  guess gwh\r\n}\r\n\r\nmolecule {\r\n 0 1\r\n SI          0.0        -3.03636189    0.1503967744\r\n SI          0.0         3.03636189    0.1503967744\r\n O           0.0         0.00000000   -0.6720662056\r\n H           0.0        -4.54756839   -1.9795468656\r\n H           0.0         4.54756839   -1.9795468656\r\n H           2.12290049 -3.58475023    1.5688329144\r\n H          -2.12290049 -3.58475023    1.5688329144\r\n H           2.12290049  3.58475023    1.5688329144\r\n H          -2.12290049  3.58475023    1.5688329144\r\n}\r\ngradient('scf')\r\n```\r\n"},"comment":{"url":"https://api.github.com/repos/psi4/psi4/issues/comments/191943783","html_url":"https://github.com/psi4/psi4/issues/298#issuecomment-191943783","issue_url":"https://api.github.com/repos/psi4/psi4/issues/298","id":191943783,"user":{"login":"loriab","id":2314730,"avatar_url":"https://avatars.githubusercontent.com/u/2314730?v=3","gravatar_id":"","url":"https://api.github.com/users/loriab","html_url":"https://github.com/loriab","followers_url":"https://api.github.com/users/loriab/followers","following_url":"https://api.github.com/users/loriab/following{/other_user}","gists_url":"https://api.github.com/users/loriab/gists{/gist_id}","starred_url":"https://api.github.com/users/loriab/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/loriab/subscriptions","organizations_url":"https://api.github.com/users/loriab/orgs","repos_url":"https://api.github.com/users/loriab/repos","events_url":"https://api.github.com/users/loriab/events{/privacy}","received_events_url":"https://api.github.com/users/loriab/received_events","type":"User","site_admin":false},"created_at":"2016-03-03T20:15:45Z","updated_at":"2016-03-03T20:15:45Z","body":"For future reference and for the robustness of https://github.com/psi4/psi4/pull/301, I'd like to know the answer to the standard orientation question in https://github.com/psi4/psi4/issues/298#issuecomment-191476636, if anyone in the know can supply it."}}