{"action":"closed","issue":{"url":"https://api.github.com/repos/ValeevGroup/tiledarray/issues/32","labels_url":"https://api.github.com/repos/ValeevGroup/tiledarray/issues/32/labels{/name}","comments_url":"https://api.github.com/repos/ValeevGroup/tiledarray/issues/32/comments","events_url":"https://api.github.com/repos/ValeevGroup/tiledarray/issues/32/events","html_url":"https://github.com/ValeevGroup/tiledarray/issues/32","id":108735973,"number":32,"title":"Possible Performance Issue with DirectTile Array Contraction?","user":{"login":"pchong90","id":3442099,"avatar_url":"https://avatars.githubusercontent.com/u/3442099?v=3","gravatar_id":"","url":"https://api.github.com/users/pchong90","html_url":"https://github.com/pchong90","followers_url":"https://api.github.com/users/pchong90/followers","following_url":"https://api.github.com/users/pchong90/following{/other_user}","gists_url":"https://api.github.com/users/pchong90/gists{/gist_id}","starred_url":"https://api.github.com/users/pchong90/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/pchong90/subscriptions","organizations_url":"https://api.github.com/users/pchong90/orgs","repos_url":"https://api.github.com/users/pchong90/repos","events_url":"https://api.github.com/users/pchong90/events{/privacy}","received_events_url":"https://api.github.com/users/pchong90/received_events","type":"User","site_admin":false},"labels":[{"url":"https://api.github.com/repos/ValeevGroup/tiledarray/labels/enhancement","name":"enhancement","color":"84b6eb"}],"state":"closed","locked":false,"assignee":null,"milestone":null,"comments":3,"created_at":"2015-09-28T20:04:47Z","updated_at":"2015-12-04T18:50:27Z","closed_at":"2015-12-04T18:50:27Z","body":"I noticed some inconsistency in the performance in direct tile array contraction. \r\nHere is the output. \r\n```\r\nCC Test\r\nFrozen Core: 16 electrons\r\nBlock Size in MO     16\r\nTiledRange1 Occupied ( tiles = [ 0, 2 ), elements = [ 0, 21 ) )\r\nTiledRange1 Virtual  ( tiles = [ 0, 51 ), elements = [ 0, 803 ) )\r\n\r\nBegining CC\r\nstart iteration\r\niter     deltaE                residual             energy         U/second   total/second\r\n1  0.0611231317123433  4.26012753086288e-10  -1.53904486737057  7009.242363154 7408.379613357\r\n2  0.0399401658471812  1.73605236907515e-10  -1.57898503321775  5475.195483026 5702.249691427\r\n3  0.0107532244924691  7.03545478472614e-11  -1.58973825771022  8330.972643913 8562.005677823\r\n4  0.000622645030980973  2.26645163814899e-11  -1.58911561267924  4515.994389942 4761.335676287\r\n5  0.000292624947780151  1.0037030826343e-11  -1.58882298773146  4015.300883278 4247.982380656\r\n6  0.00030492243288549  3.97572330838135e-12  -1.58912791016435  2969.095039533 3162.468504955\r\n7  0.000231114981430247  1.63338874450642e-12  -1.58889679518291  1563.37255113 1754.09951477\r\n8  4.19793105643773e-05  6.21390025858168e-13  -1.58893877449348  3897.680281818 4118.719245746\r\n9  9.66978594729717e-06  3.44425382366613e-13  -1.58892910470753  11974.894220928 12752.963265018\r\n10  5.62034317974636e-07  1.63034768374226e-13  -1.58892854267321  4978.137758322 5214.837211002\r\n```\r\nThe U part is the contraction between direct integral array with another array and it scales O(N^6).\r\n```\r\n(t2(\"a,b,i,j\")*Ca_(\"q,a\"))*Ca_(\"s,b\") + tc(\"i,q\") * tc(\"j,s\")) * direct_ao_(\"p,q,r,s\")\r\n```\r\n total - U is everything else. \r\nI notice that total - U is around 200-400 seconds per iteration. While the U time range from 1500 to 12000 seconds. \r\n\r\nI was wondering what causes this problem. It could be the integral generation in direct tile or something in TA."}}