From owner-chemistry ^%at%^ ccl.net Tue Jan 17 20:08:01 2006 From: "Abrash, Samuel sabrash[-]richmond.edu" To: CCL Subject: CCL:G: Difference Between Two Different Types of Failure to Converge Message-Id: <-30537-060117125636-1234-kv3W9qeHB1aDOlGaKk9M+w::server.ccl.net> X-Original-From: "Abrash, Samuel" Date: Tue, 17 Jan 2006 16:08:17 -0500 Sent to CCL by: "Abrash, Samuel" [sabrash(a)richmond.edu] Hi CCL Folks! I need some help understanding the difference between two different types of termination because of failure to converge. The first is the one I understand best. In this case, the optimization is set to run a maxiumum number of Berny cycles, and after the full number of allowed cycles (in my case 100), one or more of the four convergence criteria is unfulfilled. For this type of problem I have a pretty good idea of what to do. 1) Look at the output file to see if the structures are physically reasonable and moving toward convergence. 2a) If yes, just continue the job 2b) If no, try a different set of initial conditions, or modify the theory as needed. (Lots of options depending on the situation.) The second type of case is one where the failure to converge comes not on the final Berny cycle but on an early one. Here are the input file and the portion of the output file indicating the type of convergence failure for one of these jobs: Input: %chk=/home/saabrash/C2H2TCalcs/cyclopropanetrismethylene+_1.chk %mem=12mw # UHF/3-21G OPT=(calcall, maxcycle=100) SCF=qc cyclopropanetrismethylene cation PBEPBE/aug-cc-pVDZ init geom arguslab low symm 1 2 C -0.317858 1.277419 0.119868 C -0.287771 2.616099 0.000000 C 0.643137 0.346751 0.202150 C 2.040557 0.274690 0.000000 C -0.694918 -0.054486 -0.097643 C -1.569659 -1.098761 0.000000 H 0.676927 3.142444 -0.048150 H -1.227851 3.185096 -0.049928 H 2.597937 1.169980 -0.312708 H 2.570431 -0.676665 0.155427 H -1.248715 -2.043628 0.462842 H -2.595146 -0.994986 -0.384198 --link1-- %chk=/home/saabrash/C2H2TCalcs/cyclopropanetrismethylene+_1.chk %mem=12mw # UHF/6-31G Opt=(ReadFC, maxcycle=100) guess=read geom=allcheck scf=qc --link1-- %chk=/home/saabrash/C2H2TCalcs/cyclopropanetrismethylene+_1.chk %mem=15mw # UPBEPBE/aug-cc-pVDZ Opt=(ReadFC, maxcycle=100) guess=read geom=allcheck --link1-- %chk=/home/saabrash/C2H2TCalcs/cyclopropanetrismethylene+_1.chk %mem=15mw # UPBEPBE/aug-cc-pVDZ Opt=(rcfc, maxcycle=100) geom=allcheck --link1-- %chk=/home/saabrash/C2H2TCalcs/cyclopropanetrismethylene+_1.chk %mem=15mw # UPBEPBE/aug-cc-pVDZ Freq guess=read geom=allcheck The job runs successfully for the two UHF jobs. Then on the second Berny cycle of the UPBEPBE/aug-cc-pVDZ there is a failure to converge. The full output for the second cycle is: GradGradGradGradGradGradGradGradGradGradGradGradGradGradGradGradGradGrad Berny optimization. Internal Forces: Max 0.004030705 RMS 0.001018805 Search for a local minimum. Step number 2 out of a maximum of 100 All quantities printed in internal units (Hartrees-Bohrs-Radians) Update second derivatives using D2CorX and points 1 2 Trust test= 9.84D-01 RLast= 1.76D-01 DXMaxT set to 4.24D-01 Eigenvalues --- 0.00363 0.00457 0.00637 0.00716 0.00970 Eigenvalues --- 0.01542 0.03555 0.03561 0.03740 0.08693 Eigenvalues --- 0.09833 0.09905 0.11931 0.11966 0.12082 Eigenvalues --- 0.15236 0.15836 0.16085 0.33837 0.33897 Eigenvalues --- 0.37796 0.40451 0.40476 0.40507 0.40534 Eigenvalues --- 0.40557 0.42351 0.42412 0.47209 0.49435 Eigenvalues --- 1000.000001000.000001000.000001000.000001000.00000 Eigenvalues --- 1000.000001000.000001000.000001000.00001000.00000 Eigenvalues --- 1000.000001000.00000 RFO step: Lambda=-9.49095729D-05. Quartic linear search produced a step of 0.03710. Iteration 1 RMS(Cart)= 0.00420970 RMS(Int)= 0.00000257 Iteration 2 RMS(Cart)= 0.00000342 RMS(Int)= 0.00000178 Iteration 3 RMS(Cart)= 0.00000000 RMS(Int)= 0.00000178 Variable Old X -DE/DX Delta X Delta X Delta X New X (Linear) (Quad) (Total) R1 2.63333 0.00137 -0.00069 0.00371 0.00302 2.63635 R2 2.65714 0.00191 0.00154 0.00325 0.00479 2.66192 R3 2.72881 0.00062 0.00278 -0.00162 0.00116 2.72997 R4 2.07080 0.00174 0.00171 0.00319 0.00491 2.07571 R5 2.07026 0.00186 0.00172 0.00341 0.00513 2.07539 R6 2.63334 0.00137 -0.00069 0.00370 0.00301 2.63635 R7 2.72882 0.00062 0.00278 -0.00163 0.00116 2.72997 R8 2.07080 0.00174 0.00171 0.00319 0.00491 2.07571 R9 2.07026 0.00186 0.00172 0.00341 0.00513 2.07539 R10 2.55046 0.00403 -0.00217 0.01109 0.00891 2.55937 R11 2.06913 0.00170 0.00168 0.00298 0.00466 2.07379 R12 2.06913 0.00170 0.00168 0.00298 0.00466 2.07379 A1 2.56260 0.00008 -0.00069 0.00018 -0.00051 2.56210 A2 2.65828 0.00019 0.00043 0.00084 0.00127 2.65956 A3 2.10190 -0.00016 0.00002 -0.00138 -0.00136 2.10054 A4 2.10755 0.00022 0.00019 0.00124 0.00143 2.10897 A5 2.07374 -0.00006 -0.00021 0.00014 -0.00007 2.07367 A6 2.56260 0.00008 -0.00069 0.00018 -0.00050 2.56210 A7 2.65829 0.00019 0.00043 0.00083 0.00127 2.65956 A8 2.10189 -0.00016 0.00002 -0.00138 -0.00136 2.10054 A9 2.10755 0.00022 0.00019 0.00124 0.00143 2.10898 A10 2.07374 -0.00006 -0.00021 0.00014 -0.00007 2.07367 A11 2.63309 -0.00027 0.00025 -0.00101 -0.00077 2.63233 A12 2.63309 -0.00027 0.00025 -0.00102 -0.00077 2.63233 A13 2.10983 0.00000 0.00017 -0.00111 -0.00094 2.10889 A14 2.10983 0.00000 0.00017 -0.00111 -0.00094 2.10889 A15 2.06352 0.00001 -0.00034 0.00223 0.00189 2.06541 D1 0.00000 0.00000 0.00000 0.00001 0.00001 0.00001 D2 3.14159 0.00000 0.00000 0.00001 0.00001 -3.14159 D3 -3.14158 0.00000 0.00000 0.00001 0.00001 -3.14157 D4 0.00001 0.00000 0.00000 0.00001 0.00001 0.00002 D5 0.00001 0.00000 0.00000 0.00000 0.00000 0.00001 D6 -0.00001 0.00000 0.00000 0.00000 0.00000 -0.00001 D7 0.00000 0.00000 0.00000 0.00001 0.00001 0.00001 D8 -3.14159 0.00000 0.00000 0.00000 0.00000 -3.14158 D9 -3.14159 0.00000 0.00000 0.00001 0.00001 -3.14158 D10 0.00001 0.00000 0.00000 0.00001 0.00001 0.00002 D11 0.00000 0.00000 0.00000 0.00000 0.00000 0.00000 D12 3.14158 0.00000 0.00000 0.00002 0.00002 -3.14159 D13 -0.00002 0.00000 0.00000 0.00002 0.00002 0.00001 D14 -0.00002 0.00000 0.00000 0.00002 0.00002 0.00000 D15 3.14158 0.00000 0.00000 0.00002 0.00002 3.14159 Item Value Threshold Converged? Maximum Force 0.004031 0.000450 NO RMS Force 0.001019 0.000300 NO Maximum Displacement 0.010397 0.001800 NO RMS Displacement 0.004210 0.001200 NO Predicted change in Energy=-5.395842D-05 GradGradGradGradGradGradGradGradGradGradGradGradGradGradGradGradGradGrad Input orientation: --------------------------------------------------------------------- Center Atomic Atomic Coordinates (Angstroms) Number Number Type X Y Z --------------------------------------------------------------------- 1 6 0 -0.237228 0.763057 -0.028393 2 6 0 -0.534705 2.125159 -0.078167 3 6 0 0.767704 -0.223151 0.013368 4 6 0 2.135799 -0.495591 0.032816 5 6 0 -0.618580 -0.629581 0.017521 6 6 0 -1.567594 -1.595472 0.044403 7 1 0 0.272986 2.869305 -0.098334 8 1 0 -1.576033 2.473585 -0.097891 9 1 0 2.865548 0.325046 0.009436 10 1 0 2.503343 -1.529786 0.071622 11 1 0 -1.289422 -2.656312 0.083505 12 1 0 -2.633950 -1.336829 0.027627 --------------------------------------------------------------------- Distance matrix (angstroms): 1 2 3 4 5 1 C 0.000000 2 C 1.395096 0.00000 0 1.148793 -1.871634 0.000001 5 6 0 -0.876500 -0.000009 -0.000001 6 6 0 -2.230861 -0.000022 0.000000 7 1 0 2.245813 1.817045 -0.000012 8 1 0 0.667953 2.859072 0.000009 9 1 0 2.245853 -1.816996 0.000015 10 1 0 0.668017 -2.859059 -0.000011 11 1 0 -2.793270 -0.942353 0.000002 12 1 0 -2.793287 0.942299 0.000000 --------------------------------------------------------------------- Rotational constants (GHZ): 4.1801422 3.8590844 2.0066012 Standard basis: Aug-CC-pVDZ (5D, 7F) There are 192 symmetry adapted basis functions of A symmetry. Integral buffers will be 262144 words long. Raffenetti 2 integral format. Two-electron integral symmetry is turned on. 192 basis functions, 324 primitive gaussians, 204 cartesian basis functio ns 21 alpha electrons 20 beta electrons nuclear repulsion energy 186.6386459511 Hartrees. NAtoms= 12 NActive= 12 NUniq= 12 SFac= 1.00D჌ NAtFMM= 60 Big=F One-electron integrals computed using PRISM. NBasis= 192 RedAO= T NBF= 192 NBsUse= 192 1.00D-06 NBFU= 192 Initial guess read from the read-write file: Initial guess orbital symmetries: Alpha Orbitals: Occupied (A) (A) (A) (A) (A) (A) (A) (A) (A) (A) (A) (A) (A) (A) (A) (A) (A) (A) (A) (A) (A) Virtual (A) (A) (A) (A) (A) (A) (A) (A) (A) (A) (A) (A) (A) (A) (A) (A) (A) (A) (A) (A) (A) (A) (A) (A) of initial guess= 0.8964 Requested convergence on RMS density matrix=1.00D-08 within 128 cycles. Requested convergence on MAX density matrix=1.00D-06. Requested convergence on energy=1.00D-06. No special actions if energy rises. EnCoef did 4 forward-backward iterations EnCoef did 5 forward-backward iterations EnCoef did 2 forward-backward iterations EnCoef did 85 forward-backward iterations Rare condition: small coef for last iteration: -0.666D-15 EnCoef did 5 forward-backward iterations Rare condition: small coef for last iteration: 0.222D-15 EnCoef did 6 forward-backward iterations Rare condition: small coef for last iteration: 0.000D჌ EnCoef did 7 forward-backward iterations Rare condition: small coef for last iteration: 0.000D჌ Restarting incremental Fock formation. EnCoef did 100 forward-backward iterations Matrix for removal 1 Erem= -223.464925078448 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Rare condition: small coef for last iteration: -0.432D-15 Matrix for removal 1 Erem= -225.612036927259 Crem= 0.000D჌ EnCoef did 48 forward-backward iterations Matrix for removal 2 Erem= -230.056216034563 Crem= 0.000D჌ Rare condition: small coef for last iteration: 0.444D-15 Matrix for removal 1 Erem= -230.957780613922 Crem= 0.000D჌ EnCoef did 48 forward-backward iterations Matrix for removal 3 Erem= -231.371944287973 Crem= 0.000D჌ Rare condition: small coef for last iteration: -0.222D-15 Matrix for removal 6 Erem= -231.413745729862 Crem= 0.000D჌ EnCoef did 6 forward-backward iterations Matrix for removal 1 Erem= -231.416133716719 Crem= 0.000D჌ Rare condition: small coef for last iteration: 0.000D჌ Matrix for removal 13 Erem= -231.418900867161 Crem= 0.000D჌ EnCoef did 59 forward-backward iterations Matrix for removal 18 Erem= -231.419070999074 Crem= 0.000D჌ Rare condition: small coef for last iteration: -0.444D-15 Matrix for removal 11 Erem= -231.419112348980 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Matrix for removal 18 Erem= -231.419148641413 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Rare condition: small coef for last iteration: 0.000D჌ Matrix for removal 19 Erem= -231.418778276146 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Matrix for removal 9 Erem= -231.419169067006 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Rare condition: small coef for last iteration: 0.554D-15 Matrix for removal 19 Erem= -231.418942288017 Crem= 0.000D჌ EnCoef did 6 forward-backward iterations Matrix for removal 14 Erem= -231.419290263368 Crem= 0.000D჌ Rare condition: small coef for last iteration: 0.000D჌ Matrix for removal 19 Erem= -231.419107556261 Crem= 0.000D჌ EnCoef did 6 forward-backward iterations Matrix for removal 11 Erem= -231.420445394300 Crem= 0.000D჌ Rare condition: small coef for last iteration: -0.222D-15 Matrix for removal 19 Erem= -231.419071776551 Crem= 0.000D჌ EnCoef did 6 forward-backward iterations Matrix for removal 12 Erem= -231.420604168141 Crem= 0.000D჌ Rare condition: small coef for last iteration: -0.222D-15 Matrix for removal 19 Erem= -231.419149178448 Crem= 0.000D჌ Restarting incremental Fock formation. EnCoef did 100 forward-backward iterations Matrix for removal 13 Erem= -231.420647898230 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Rare condition: small coef for last iteration: -0.111D-14 Matrix for removal 19 Erem= -231.418949995443 Crem= 0.000D჌ EnCoef did 6 forward-backward iterations Matrix for removal 17 Erem= -231.420648694361 Crem= 0.000D჌ Rare condition: small coef for last iteration: 0.111D-15 Matrix for removal 19 Erem= -231.419096135031 Crem= 0.000D჌ EnCoef did 6 forward-backward iterations Matrix for removal 9 Erem= -231.420657719207 Crem= 0.000D჌ Rare condition: small coef for last iteration: 0.000D჌ Matrix for removal 19 Erem= -231.419104154891 Crem= 0.000D჌ EnCoef did 6 forward-backward iterations Matrix for removal 14 Erem= -231.420671893769 Crem= 0.000D჌ Rare condition: small coef for last iteration: 0.000D჌ Matrix for removal 19 Erem= -231.419081387961 Crem= 0.000D჌ EnCoef did 6 forward-backward iterations Matrix for removal 19 Erem= -231.420658305176 Crem= 0.000D჌ Rare condition: small coef for last iteration: 0.111D-15 Matrix for removal 19 Erem= -231.419145661317 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Matrix for removal 17 Erem= -231.420673187415 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Rare condition: small coef for last iteration: -0.444D-15 Matrix for removal 19 Erem= -231.418960715007 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Matrix for removal 16 Erem= -231.420675973150 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Rare condition: small coef for last iteration: -0.444D-15 Matrix for removal 19 Erem= -231.419021266252 Crem= 0.000D჌ EnCoef did 14 forward-backward iterations Matrix for removal 16 Erem= -231.420681296646 Crem= 0.000D჌ Rare condition: small coef for last iteration: -0.444D-15 Matrix for removal 19 Erem= -231.419335961191 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Matrix for removal 18 Erem= -231.420587572061 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Rare condition: small coef for last iteration: -0.440D-15 Matrix for removal 19 Erem= -231.418544675637 Crem= 0.000D჌ EnCoef did 14 forward-backward iterations Matrix for removal 11 Erem= -231.420684293649 Crem= 0.000D჌ Rare condition: small coef for last iteration: 0.000D჌ Matrix for removal 19 Erem= -231.419477236327 Crem= 0.000D჌ Restarting incremental Fock formation. EnCoef did 100 forward-backward iterations Matrix for removal 18 Erem= -231.420534345081 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Rare condition: small coef for last iteration: -0.442D-15 Matrix for removal 19 Erem= -231.418796677540 Crem= 0.000D჌ EnCoef did 6 forward-backward iterations Matrix for removal 10 Erem= -231.419651241752 Crem= 0.000D჌ Rare condition: small coef for last iteration: 0.111D-15 Matrix for removal 19 Erem= -231.419280599829 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Matrix for removal 18 Erem= -231.420608902185 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Rare condition: small coef for last iteration: 0.221D-15 Matrix for removal 19 Erem= -231.418906193179 Crem= 0.000D჌ EnCoef did 6 forward-backward iterations Matrix for removal 19 Erem= -231.420586795007 Crem= 0.000D჌ Rare condition: small coef for last iteration: -0.222D-15 Matrix for removal 19 Erem= -231.419285531894 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Matrix for removal 12 Erem= -231.420684711108 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Rare condition: small coef for last iteration: 0.221D-15 Matrix for removal 19 Erem= -231.418892731624 Crem= 0.000D჌ EnCoef did 6 forward-backward iterations Matrix for removal 19 Erem= -231.420585363376 Crem= 0.000D჌ Rare condition: small coef for last iteration: 0.000D჌ Matrix for removal 19 Erem= -231.419289049853 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Matrix for removal 14 Erem= -231.420702235767 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Rare condition: small coef for last iteration: 0.331D-15 Matrix for removal 19 Erem= -231.418882803565 Crem= 0.000D჌ EnCoef did 6 forward-backward iterations Matrix for removal 19 Erem= -231.420581194769 Crem= 0.000D჌ Rare condition: small coef for last iteration: -0.222D-15 Matrix for removal 19 Erem= -231.419299060760 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Matrix for removal 13 Erem= -231.420723664654 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Rare condition: small coef for last iteration: -0.441D-15 Matrix for removal 19 Erem= -231.418855077350 Crem= 0.000D჌ EnCoef did 14 forward-backward iterations Matrix for removal 12 Erem= -231.420727388183 Crem= 0.000D჌ Rare condition: small coef for last iteration: -0.222D-15 Matrix for removal 19 Erem= -231.419324576409 Crem= 0.000D჌ Restarting incremental Fock formation. EnCoef did 100 forward-backward iterations Matrix for removal 18 Erem= -231.420570563941 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Rare condition: small coef for last iteration: 0.110D-15 Matrix for removal 19 Erem= -231.418780647653 Crem= 0.000D჌ EnCoef did 14 forward-backward iterations Matrix for removal 11 Erem= -231.420730549360 Crem= 0.000D჌ Rare condition: small coef for last iteration: 0.000D჌ Matrix for removal 19 Erem= -231.419384341437 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Matrix for removal 18 Erem= -231.420545387770 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Rare condition: small coef for last iteration: -0.665D-15 Matrix for removal 19 Erem= -231.419018218195 Crem= 0.000D჌ EnCoef did 14 forward-backward iterations Matrix for removal 18 Erem= -231.420693067494 Crem= 0.000D჌ Rare condition: small coef for last iteration: 0.444D-15 Matrix for removal 19 Erem= -231.419466794992 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Matrix for removal 18 Erem= -231.420508813558 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Rare condition: small coef for last iteration: -0.665D-15 Matrix for removal 19 Erem= -231.419030539317 Crem= 0.000D჌ EnCoef did 14 forward-backward iterations Matrix for removal 18 Erem= -231.420688269172 Crem= 0.000D჌ Rare condition: small coef for last iteration: 0.777D-15 Matrix for removal 19 Erem= -231.419448841266 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Matrix for removal 18 Erem= -231.420516657136 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Rare condition: small coef for last iteration: 0.440D-15 Matrix for removal 19 Erem= -231.418503747344 Crem= 0.000D჌ EnCoef did 15 forward-backward iterations Matrix for removal 13 Erem= -231.420736420738 Crem= 0.000D჌ Rare condition: small coef for last iteration: 0.111D-15 Matrix for removal 19 Erem= -231.419515644416 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Matrix for removal 18 Erem= -231.420488445027 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Rare condition: small coef for last iteration: -0.220D-15 Matrix for removal 19 Erem= -231.418673619125 Crem= 0.000D჌ EnCoef did 14 forward-backward iterations Matrix for removal 9 Erem= -231.420739298607 Crem= 0.000D჌ Rare condition: small coef for last iteration: 0.222D-15 Matrix for removal 18 Erem= -231.420515847041 Crem= 0.000D჌ Restarting incremental Fock formation. EnCoef did 100 forward-backward iterations Matrix for removal 18 Erem= -231.419453081651 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Rare condition: small coef for last iteration: 0.144D-14 Matrix for removal 19 Erem= -231.419131280349 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Matrix for removal 18 Erem= -231.420653956973 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Rare condition: small coef for last iteration: 0.222D-15 Matrix for removal 19 Erem= -231.419031179958 Crem= 0.000D჌ EnCoef did 14 forward-backward iterations Matrix for removal 18 Erem= -231.420688123736 Crem= 0.000D჌ Rare condition: small coef for last iteration: -0.666D-15 Matrix for removal 18 Erem= -231.420517077761 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Matrix for removal 18 Erem= -231.419447848080 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Rare condition: small coef for last iteration: -0.666D-15 Matrix for removal 19 Erem= -231.419123693065 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Matrix for removal 18 Erem= -231.420655788332 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Rare condition: small coef for last iteration: 0.111D-15 Matrix for removal 19 Erem= -231.419006604895 Crem= 0.000D჌ EnCoef did 14 forward-backward iterations Matrix for removal 12 Erem= -231.420741474519 Crem= 0.000D჌ Rare condition: small coef for last iteration: -0.222D-15 Matrix for removal 19 Erem= -231.419483006932 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Matrix for removal 18 Erem= -231.420501705978 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Rare condition: small coef for last iteration: 0.221D-15 Matrix for removal 19 Erem= -231.418891457091 Crem= 0.000D჌ EnCoef did 6 forward-backward iterations Matrix for removal 19 Erem= -231.420584815358 Crem= 0.000D჌ Rare condition: small coef for last iteration: -0.222D-15 Matrix for removal 19 Erem= -231.419290379712 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Matrix for removal 17 Erem= -231.420697653495 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Rare condition: small coef for last iteration: -0.662D-15 Matrix for removal 19 Erem= -231.418878558166 Crem= 0.000D჌ EnCoef did 6 forward-backward iterations Matrix for removal 19 Erem= -231.420579763623 Crem= 0.000D჌ Rare condition: small coef for last iteration: 0.000D჌ Matrix for removal 19 Erem= -231.419302558715 Crem= 0.000D჌ Restarting incremental Fock formation. EnCoef did 100 forward-backward iterations Matrix for removal 17 Erem= -231.420741463049 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Rare condition: small coef for last iteration: 0.000D჌ Matrix for removal 19 Erem= -231.418842382202 Crem= 0.000D჌ EnCoef did 14 forward-backward iterations Matrix for removal 12 Erem= -231.420745177864 Crem= 0.000D჌ Rare condition: small coef for last iteration: -0.111D-14 Matrix for removal 19 Erem= -231.419335069289 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Matrix for removal 18 Erem= -231.420566191137 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Rare condition: small coef for last iteration: -0.220D-15 Matrix for removal 19 Erem= -231.418736422553 Crem= 0.000D჌ EnCoef did 14 forward-backward iterations Matrix for removal 16 Erem= -231.420746777662 Crem= 0.000D჌ Rare condition: small coef for last iteration: -0.444D-15 Matrix for removal 19 Erem= -231.419414870194 Crem= 0.000D჌ EnCoef did 100 forward-backward iterations Matrix for removal 18 Erem= -231.420532350979 Crem= 0.000D჌ >>>>>>>>>> Convergence criterion not met. SCF Done: E(UPBE-PBE) = -231.418804396 A.U. after 129 cycles Convg = 0.3553D-03 -V/T = 2.0061 S**2 = 0.7575 Annihilation of the first spin contaminant: S**2 before annihilation 0.7575, after 0.7500 Convergence failure -- run terminated. Error termination via Lnk1e in /usr/global/g03/l502.exe at Thu Dec 29 17:09:52 2005. Job cpu time: 0 days 4 hours 5 minutes 9.7 seconds. File lengths (MBytes): RWF= 51 Int= 0 D2E= 0 Chk= 7 Scr= 1 So I have two questions: 1) Is this a failure in geometric convergence, convergence of the integrals or what? I really don't understand WHAT it is that isn't converging. 2) What types of remedies are available when this occurs? If you saw this in one of your jobs what would you do next? Thanks, and once again I appreciate your help. Best, Sam