[molpro-user] unreasonable norm in UCCSD(T)

Marissa Weichman mweichman at gmail.com
Tue Jun 7 19:03:18 CEST 2016


Hello all,

I am trying to run single-point energy calculations for small iron monoxide
clusters in MOLPRO 2010.1. I am using UCCSD(T)/AVDZ at cluster geometries
previously optimized with DFT. Being ferromagnetic, these clusters have
incredibly high electronic spin, which I believe is causing some problems.

For a few of the spin states I'm interested in, my UCCSD(T) calculation
converges very nicely. In a few cases, however, the RHF and RMP2
calculations converge without issue, but the UCCSD(T) part only gets a few
iterations before the value of SQ. NORM starts increasing, and MOLPRO
throws the "UNREASONABLE NORM. CALCULATION STOPPED" error and crashes.

I have read that this error is often caused by a strange or incorrect
electron configuration. However, I have thoroughly checked the electron
orbital occupations in the prior RHF and RMP2 steps against my sensible DFT
calculations, and everything is consistent. I also played around
extensively with different level shift parameters and convergence
algorithms (as recommended here
<https://www.molpro.net/info/2015.1/doc/manual/node177.html>) and couldn't
change this behavior.

If I use "set,cc_norm_max=100.0" (as I show in the example input below),
and ignore the fact that SQ. NORM gets to a value of 20+, the UCCSD(T)
calculation does converge (as also shown below). But I do get a final
energy that is fishy compared to my other calculations that converged
normally. Are there any other tricks I should be trying?

Thank you!

Marissa

--

Example input:

***,Fe4O_13_uccsdt_avdz
memory,3000,mw

geomtyp=xyz
geometry={
5 ! number of atoms

optimized Fe4O 13-tet c2v with TPSS/6-311+g*
O 0.0000 0.0000 2.0572
Fe 0.0000 1.2201 0.7011
Fe 0.0000 -1.2201 0.7011
Fe -1.1884 0.0000 -0.9952
Fe 1.1884 0.0000 -0.9952
}

set,charge=0
set,spin=12 ! spin=2s, so this is the 13-tet

basis={default=avdz}

set,cc_norm_max=100.0
hf,maxit=200;shift,-1.0,-0.5
uccsd(t),maxit=200


--

Relevant part of the output:

 Starting UCCSD calculation

 ITER.      SQ.NORM     CORR.ENERGY   TOTAL ENERGY   ENERGY CHANGE
 DEN1      VAR(S)    VAR(P)  DIIS     TIME
   1      1.52677747    -1.24852238 -5125.26012928    -1.24852238
 -0.22253355  0.13D+00  0.62D-01  0  0    79.24
   2      1.81205924    -1.45502934 -5125.46663624    -0.20650696
 -0.08456664  0.35D-01  0.37D-01  1  1   122.30
   3      1.87264052    -1.40483018 -5125.41643708     0.05019916
 -0.01720839  0.16D-01  0.38D-02  2  2   163.42
   4      2.07225408    -1.42258668 -5125.43419359    -0.01775650
 -0.01100110  0.97D-02  0.27D-02  3  3   202.18
   5      2.51432027    -1.45370712 -5125.46531403    -0.03112044
 -0.00773249  0.78D-02  0.16D-02  4  4   240.94
   6      2.95585742    -1.47016080 -5125.48176770    -0.01645367
 -0.00631234  0.62D-02  0.14D-02  5  5   279.89
   7      3.43510225    -1.48164422 -5125.49325113    -0.01148343
 -0.00521287  0.48D-02  0.12D-02  6  6   319.00
   8      4.18490168    -1.49443359 -5125.50604049    -0.01278936
 -0.00441521  0.41D-02  0.97D-03  6  4   358.15
   9      4.86484426    -1.50303940 -5125.51464630    -0.00860581
 -0.00393151  0.36D-02  0.84D-03  6  1   401.27
  10      5.79617501    -1.51247370 -5125.52408060    -0.00943430
 -0.00347500  0.32D-02  0.68D-03  6  4   446.76
  11      6.73168654    -1.51863335 -5125.53024025    -0.00615965
 -0.00317530  0.29D-02  0.60D-03  6  5   491.01
  12      7.88625768    -1.52758897 -5125.53919588    -0.00895563
 -0.00282700  0.26D-02  0.53D-03  6  2   530.81
  13      8.95620834    -1.53041514 -5125.54202205    -0.00282617
 -0.00251092  0.23D-02  0.42D-03  6  3   571.93
  14     10.33352126    -1.53597414 -5125.54758104    -0.00555899
 -0.00219265  0.20D-02  0.41D-03  6  6   611.25
  15     11.13695846    -1.53778236 -5125.54938927    -0.00180822
 -0.00190764  0.17D-02  0.35D-03  6  1   650.78
  16     12.73368576    -1.54166175 -5125.55326865    -0.00387938
 -0.00154031  0.13D-02  0.33D-03  6  2   690.20
  17     14.45438474    -1.54585419 -5125.55746109    -0.00419244
 -0.00122090  0.99D-03  0.29D-03  6  4   729.68
  18     14.89809783    -1.54671418 -5125.55832108    -0.00085998
 -0.00112134  0.86D-03  0.30D-03  6  6   769.08
  19     15.50867378    -1.54829204 -5125.55989895    -0.00157787
 -0.00082978  0.59D-03  0.25D-03  6  2   811.53
  20     17.87941931    -1.55230457 -5125.56391147    -0.00401253
 -0.00047247  0.32D-03  0.15D-03  6  5   855.72
  21     17.68841351    -1.55176171 -5125.56336861     0.00054286
 -0.00042453  0.27D-03  0.15D-03  6  2   896.12
  22     17.65413588    -1.55194576 -5125.56355266    -0.00018405
 -0.00032914  0.20D-03  0.12D-03  6  1   937.49
  23     18.17319799    -1.55253493 -5125.56414183    -0.00058917
 -0.00021239  0.15D-03  0.70D-04  6  3   980.50
  24     18.33739898    -1.55272718 -5125.56433409    -0.00019226
 -0.00016958  0.12D-03  0.59D-04  6  4  1021.76
  25     18.49514646    -1.55304748 -5125.56465439    -0.00032030
 -0.00014060  0.10D-03  0.46D-04  6  3  1063.06
  26     19.02753787    -1.55384276 -5125.56544966    -0.00079527
 -0.00010626  0.78D-04  0.34D-04  6  6  1102.74
  27     19.29226045    -1.55410366 -5125.56571056    -0.00026090
 -0.00008659  0.61D-04  0.30D-04  6  2  1142.27
  28     19.69307693    -1.55471830 -5125.56632520    -0.00061464
 -0.00006294  0.46D-04  0.21D-04  6  5  1181.74
  29     19.91148754    -1.55473878 -5125.56634568    -0.00002049
 -0.00005084  0.37D-04  0.17D-04  6  3  1221.21
  30     20.21334043    -1.55511008 -5125.56671699    -0.00037130
 -0.00004094  0.27D-04  0.15D-04  6  6  1260.68
  31     20.56654112    -1.55524288 -5125.56684978    -0.00013280
 -0.00002973  0.20D-04  0.11D-04  6  4  1300.15
  32     20.96647640    -1.55551919 -5125.56712609    -0.00027631
 -0.00002128  0.13D-04  0.86D-05  6  1  1339.62
  33     21.31372706    -1.55571914 -5125.56732604    -0.00019994
 -0.00001535  0.85D-05  0.66D-05  6  3  1378.74
  34     21.59806637    -1.55579609 -5125.56740299    -0.00007696
 -0.00001160  0.61D-05  0.51D-05  6  6  1423.79
  35     21.85187169    -1.55601396 -5125.56762086    -0.00021787
 -0.00000799  0.44D-05  0.33D-05  6  5  1468.81
  36     22.06696413    -1.55605417 -5125.56766107    -0.00004021
 -0.00000573  0.36D-05  0.21D-05  6  2  1513.78
  37     22.16220603    -1.55611503 -5125.56772193    -0.00006086
 -0.00000459  0.30D-05  0.16D-05  6  3  1554.29
  38     22.27870356    -1.55611929 -5125.56772619    -0.00000426
 -0.00000336  0.24D-05  0.10D-05  6  5  1593.42
  39     22.32591879    -1.55615097 -5125.56775787    -0.00003168
 -0.00000273  0.21D-05  0.75D-06  6  3  1637.26
  40     22.39863057    -1.55616423 -5125.56777113    -0.00001326
 -0.00000228  0.17D-05  0.63D-06  6  2  1682.24
  41     22.47648448    -1.55620346 -5125.56781037    -0.00003924
 -0.00000191  0.14D-05  0.55D-06  6  4  1726.86
  42     22.58214664    -1.55625981 -5125.56786671    -0.00005635
 -0.00000158  0.11D-05  0.51D-06  6  6  1767.27
  43     22.69790660    -1.55631690 -5125.56792381    -0.00005709
 -0.00000121  0.79D-06  0.39D-06  6  1  1809.98
  44     22.73099295    -1.55634345 -5125.56795035    -0.00002654
 -0.00000104  0.64D-06  0.36D-06  6  6  1855.64
  45     22.77366705    -1.55640959 -5125.56801650    -0.00006615
 -0.00000067  0.44D-06  0.23D-06  6  2  1899.84
  46     22.79457772    -1.55642812 -5125.56803502    -0.00001853
 -0.00000057  0.37D-06  0.20D-06  6  6  1944.80
  47     22.79999700    -1.55644503 -5125.56805193    -0.00001691
 -0.00000051  0.32D-06  0.18D-06  6  2  1989.61
  48     22.81333024    -1.55645875 -5125.56806566    -0.00001373
 -0.00000043  0.27D-06  0.16D-06  6  6  2029.01
  49     22.81751109    -1.55648633 -5125.56809323    -0.00002758
 -0.00000030  0.16D-06  0.13D-06  6  1  2068.36
  50     22.81697710    -1.55649854 -5125.56810544    -0.00001221
 -0.00000023  0.13D-06  0.97D-07  6  5  2109.24
  51     22.83327975    -1.55649937 -5125.56810627    -0.00000083
 -0.00000015  0.81D-07  0.68D-07  6  3  2150.05
  52     22.85082754    -1.55651415 -5125.56812105    -0.00001478
 -0.00000012  0.60D-07  0.53D-07  6  4  2192.50
  53     22.87017137    -1.55652036 -5125.56812726    -0.00000621
 -0.00000008  0.48D-07  0.34D-07  6  5  2231.65
  54     22.87734936    -1.55652583 -5125.56813273    -0.00000547
 -0.00000007  0.40D-07  0.28D-07  6  4  2270.86
  55     22.88451494    -1.55652322 -5125.56813013     0.00000261
 -0.00000004  0.28D-07  0.17D-07  6  6  2310.10
  56     22.88141922    -1.55652418 -5125.56813108    -0.00000096
 -0.00000003  0.24D-07  0.99D-08  6  2  2355.19
  57     22.88292739    -1.55652095 -5125.56812785     0.00000324
 -0.00000003  0.20D-07  0.83D-08  6  3  2394.37
  58     22.88398875    -1.55652179 -5125.56812869    -0.00000084
 -0.00000002  0.18D-07  0.65D-08  6  5  2433.51
  59     22.89459290    -1.55652373 -5125.56813063    -0.00000194
 -0.00000002  0.12D-07  0.50D-08  6  1  2472.72
  60     22.90307444    -1.55652446 -5125.56813136    -0.00000073
 -0.00000001  0.83D-08  0.44D-08  6  6  2511.84
  61     22.91111322    -1.55652661 -5125.56813352    -0.00000215
 -0.00000001  0.60D-08  0.35D-08  6  4  2550.93

 Norm of t1 vector:      2.47041773      S-energy:    -0.12884505      T1
diagnostic:  0.26231356
                                                                       D1
diagnostic:  0.87368671
 Norm of t2 vector:      3.97594636      P-energy:    -1.42768156
                                         Alpha-Beta:  -0.92084599
                                         Alpha-Alpha: -0.33717095
                                         Beta-Beta:   -0.16966463

-- 
Marissa L. Weichman
Neumark Group
Department of Chemistry
University of California, Berkeley
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