CCL: Problem SCF convergence(energy oscillation) in extended pi system/G03



 Sent to CCL by: "Ronald C. Bakus" [rbakus!=!chem.ucsb.edu]
 Im having some issues with a problem convergence case for a extended pi system.
 Without diffuse functions, convergence is fine, however, upon addition of
 diffuse functions the optimization will get close to completing, but on one of
 the last scf cycles, the energy will decrease and then oscillate around
 convergence.  The homo-lumo gap is small, slightly less than .2H. I have already
 tried various combinations of the standard ways of dealing with problem scf (qc,
 vshift=x (x=150,300,500,1000), nodiis, novaracc, optimization+freq calc without
 diffuse as starting point for diffuse, etc.) with no success.  I was hoping to
 perhaps get some input on other ways to deal with the problem.  The diffuse
 functions will be important to later phases of the calculations.
 Sample Input (I have tried both syn and anti conformers of the dimethylamino
 groups)
 ------
 %chk=dsb.chk
 %mem=20MW
 #p opt b3lyp/6-31+g(d,p) geom=connectivity int=ultrafine cphf=ultrafine
 formcheck
 dsb14 opt
 0 1
  C
  C                  1              B1
  C                  2              B2    1              A1
  C                  3              B3    2              A2    1              D1
  C                  4              B4    3              A3    2              D2
  C                  5              B5    4              A4    3              D3
  H                  1              B6    2              A5    3              D4
  H                  2              B7    1              A6    6              D5
  H                  4              B8    3              A7    2              D6
  H                  5              B9    4              A8    3              D7
  C                  3             B10    2              A9    1              D8
  H                 11             B11    3             A10    2              D9
  C                 11             B12    3             A11    2             D10
  H                 13             B13   11             A12    3             D11
  C                 13             B14   11             A13    3             D12
  C                 15             B15   13             A14   11             D13
  C                 15             B16   13             A15   11             D14
  C                 16             B17   15             A16   13             D15
  H                 16             B18   15             A17   13             D16
  C                 17             B19   15             A18   13             D17
  H                 17             B20   15             A19   13             D18
  C                 18             B21   16             A20   15             D19
  H                 18             B22   16             A21   15             D20
  H                 20             B23   17             A22   15             D21
  C                 22             B24   18             A23   16             D22
  H                 25             B25   22             A24   18             D23
  C                 25             B26   22             A25   18             D24
  H                 27             B27   25             A26   22             D25
  C                 27             B28   25             A27   22             D26
  C                 29             B29   27             A28   25             D27
  C                 29             B30   27             A29   25             D28
  C                 30             B31   29             A30   27             D29
  H                 30             B32   29             A31   27             D30
  C                 31             B33   29             A32   27             D31
  H                 31             B34   29             A33   27             D32
  C                 32             B35   30             A34   29             D33
  H                 32             B36   30             A35   29             D34
  H                 34             B37   31             A36   29             D35
  N                  6             B38    5             A37    4             D36
  N                 36             B39   32             A38   30             D37
  C                 40             B40   36             A39   32             D38
  H                 41             B41   40             A40   36             D39
  H                 41             B42   40             A41   36             D40
  H                 41             B43   40             A42   36             D41
  C                 40             B44   36             A43   32             D42
  H                 45             B45   40             A44   36             D43
  H                 45             B46   40             A45   36             D44
  H                 45             B47   40             A46   36             D45
  C                 39             B48    6             A47    5             D46
  H                 49             B49   39             A48    6             D47
  H                 49             B50   39             A49    6             D48
  H                 49             B51   39             A50    6             D49
  C                 39             B52    6             A51    5             D50
  H                 53             B53   39             A52    6             D51
  H                 53             B54   39             A53    6             D52
  H                 53             B55   39             A54    6             D53
    B1             1.38590600
    B2             1.40879299
    B3             1.40676154
    B4             1.38827161
    B5             1.41292513
    B6             1.08298050
    B7             1.08583864
    B8             1.08754627
    B9             1.08285660
    B10            1.45944010
    B11            1.08912863
    B12            1.35168559
    B13            1.08891058
    B14            1.46036881
    B15            1.41101301
    B16            1.40955110
    B17            1.38649352
    B18            1.08745064
    B19            1.38650055
    B20            1.08563046
    B21            1.40957879
    B22            1.08563312
    B23            1.08745466
    B24            1.46038208
    B25            1.08891491
    B26            1.35170500
    B27            1.08912993
    B28            1.45944392
    B29            1.40677707
    B30            1.40881876
    B31            1.38826824
    B32            1.08755006
    B33            1.38589746
    B34            1.08584524
    B35            1.41292195
    B36            1.08285687
    B37            1.08298484
    B38            1.38847165
    B39            1.38841623
    B40            1.45260430
    B41            1.09097759
    B42            1.10130937
    B43            1.09581331
    B44            1.45285452
    B45            1.09097407
    B46            1.09576437
    B47            1.10121929
    B48            1.45286246
    B49            1.09098248
    B50            1.10122787
    B51            1.09575774
    B52            1.45262017
    B53            1.09098468
    B54            1.09579664
    B55            1.10131866
    A1           122.07360923
    A2           116.25323549
    A3           122.52104756
    A4           120.89016562
    A5           118.44193028
    A6           118.09314223
    A7           118.89576382
    A8           118.63570829
    A9           124.25260979
    A10          114.09091838
    A11          127.48313332
    A12          118.61687356
    A13          127.13426723
    A14          119.07045476
    A15          124.12563764
    A16          122.03442793
    A17          118.76061142
    A18          121.16247464
    A19          119.98708840
    A20          121.16222854
    A21          118.85028804
    A22          119.20697504
    A23          124.12861653
    A24          114.24477657
    A25          127.13686366
    A26          118.42466374
    A27          127.48931804
    A28          119.49046853
    A29          124.25717650
    A30          122.52172015
    A31          118.89429417
    A32          122.07417140
    A33          119.83267571
    A34          120.89096115
    A35          118.63484888
    A36          118.44040512
    A37          121.62197526
    A38          121.62236490
    A39          119.34902804
    A40          109.13960300
    A41          112.95155437
    A42          111.01772561
    A43          119.49930105
    A44          109.10238405
    A45          111.07362683
    A46          112.96782739
    A47          119.49517384
    A48          109.10177009
    A49          112.97116251
    A50          111.06987287
    A51          119.34521560
    A52          109.13771153
    A53          111.01169226
    A54          112.95688048
    D1            -0.35125191
    D2             0.32638204
    D3             0.40233558
    D4           179.48620457
    D5          -179.90506437
    D6          -179.42169103
    D7          -179.52106898
    D8           180.00000000
    D9           178.40429122
    D10           -1.82780326
    D11           -0.31757066
    D12          179.89196744
    D13          178.73985841
    D14           -1.28157819
    D15         -179.92043875
    D16           -0.00000000
    D17          179.91842635
    D18           -0.19884610
    D19           -0.05473033
    D20          179.90530662
    D21          179.97520249
    D22         -179.96404995
    D23         -179.65549459
    D24            0.42839517
    D25            0.19711844
    D26         -179.94034630
    D27         -179.19548240
    D28            1.14931637
    D29         -179.94453526
    D30           -0.22485722
    D31          179.95511206
    D32            0.34504623
    D33           -0.42074545
    D34          179.50779600
    D35         -179.50941383
    D36          178.51739236
    D37         -178.52921489
    D38          171.94094710
    D39          178.43928000
    D40          -61.14986272
    D41           60.18975765
    D42           11.63000000
    D43         -178.68286485
    D44          -60.46741792
    D45           60.95449961
    D46          170.08048307
    D47          178.67201365
    D48          -60.96543365
    D49           60.45777828
    D50            9.82506217
    D51         -178.40320889
    D52          -60.16058276
    D53           61.18077952
  1 2 2.0 6 1.5 7 1.0
  2 3 1.5 8 1.0
  3 4 1.5 11 1.0
  4 5 1.5 9 1.0
  5 6 1.5 10 1.0
  6 39 1.0
  7
  8
  9
  10
  11 12 1.0 13 2.0
  12
  13 14 1.0 15 1.0
  14
  15 16 1.5 17 1.5
  16 18 1.5 19 1.0
  17 20 1.5 21 1.0
  18 22 1.5 23 1.0
  19
  20 22 1.5 24 1.0
  21
  22 25 1.0
  23
  24
  25 26 1.0 27 2.0
  26
  27 28 1.0 29 1.0
  28
  29 30 1.5 31 1.5
  30 32 1.5 33 1.0
  31 34 2.0 35 1.0
  32 36 1.5 37 1.0
  33
  34 36 1.5 38 1.0
  35
  36 40 1.0
  37
  38
  39 49 1.0 53 1.0
  40 41 1.0 45 1.0
  41 42 1.0 43 1.0 44 1.0
  42
  43
  44
  45 46 1.0 47 1.0 48 1.0
  46
  47
  48
  49 50 1.0 51 1.0 52 1.0
  50
  51
  52
  53 54 1.0 55 1.0 56 1.0
  54
  55
  56
 -----
 I hope that someone far brighter than me has a suggestion, I have been fighting
 with this for 2 weeks.
 Ron Bakus
 rbakus _ chem.ucsb.edu
 UCSB