[molpro-user] repeated CASSCF calculation - two different results:

[Peter Burger]

Dear experts,

I have repeated a CASSCF calculation and obtain two different results..

Final CASSCF energies:

-614.27913353 vs -614.29682976 H

The reference states differ in the last digit (they  converged with the 
same number of SCF cycles).

  !UHF STATE 1.2 Energy               -614.174983749842
  !UHF STATE 1.2 Energy               -614.174983749841

The codes were run in parallel on 16 cores on the exact same hardware 
(Molpro version 2015.1)

Is this a sign of numerical instability - either code or hardware?

I there a cure?

Best regards

Peter

  Number of orbital rotations:     5453   (   104 Core/Active   3811 
Core/Virtual   0 Active/Active   1538 Active/Virtual)
  Total number of variables:    2582077


  ITER. MIC  NCI  NEG     ENERGY(VAR)     ENERGY(PROJ)   ENERGY 
CHANGE     GRAD(0)  GRAD(ORB)   GRAD(CI)     STEP       TIME

    1  110   27    0    -614.20752867    -614.25168006 -0.04415139    
0.06581535 0.00265426 0.01172985  0.17D+01    176.90
    2   70   47    0    -614.25464720    -614.25941429 -0.00476708    
0.05645649 0.00004046 0.00028798  0.52D+00    441.24
    3   90   42    0    -614.25993568    -614.26129568 -0.00136000    
0.00660288 0.00000178 0.00446927  0.43D+00    678.86
    4   70   46    0    -614.26567248    -614.27766280 -0.01199032    
0.04259532 0.00039830 0.00059713  0.68D+00    934.54
    5   70   44    0    -614.27881809    -614.27912994 -0.00031185    
0.01865182 0.00000968 0.00003024  0.96D-01   1182.08
    6   60   31    0    -614.27913327    -614.27913353 -0.00000026    
0.00029918 0.00000000 0.00000918  0.46D-02   1352.32
    7   60   16    0    -614.27913353    -614.27913353 0.00000000    
0.00000253 0.00000000 0.00000000  0.00D+00   1444.36

  ** WVFN ****  CONVERGENCE REACHED, FINAL GRADIENT:  0.25D-05

  Number of orbital rotations:     5453   (   104 Core/Active   3811 
Core/Virtual   0 Active/Active   1538 Active/Virtual)
  Total number of variables:    2582077


  ITER. MIC  NCI  NEG     ENERGY(VAR)     ENERGY(PROJ)   ENERGY 
CHANGE     GRAD(0)  GRAD(ORB)   GRAD(CI)     STEP       TIME

    1  110   27    0    -614.20752867    -614.25165564 -0.04412697    
0.06581535 0.00290952 0.01167685  0.17D+01    175.29
    2   70   47    0    -614.25457713    -614.25932641 -0.00474929    
0.05596799 0.00004860 0.00033594  0.52D+00    432.76
    3   86   42    0    -614.25991802    -614.26002741 -0.00010939    
0.00726826 0.00000001 0.00112142  0.13D+00    671.47
    4   90   42    0    -614.26005664    -614.26022502 -0.00016838    
0.00457481 0.00000001 0.00037366  0.17D+00    906.91
    5   90   40    0    -614.26026701    -614.26035755 -0.00009054    
0.00412629 0.00000002 0.00033484  0.13D+00   1131.90
    6   88   40    0    -614.26037277    -614.26041086 -0.00003809    
0.00187738 0.00000002 0.00036759  0.11D+00   1354.14
    7  100   40    0    -614.26041739    -614.26045063 -0.00003324    
0.00142076 0.00000000 0.00049945  0.12D+00   1578.86
    8   90   41    0    -614.26046420    -614.26063796 -0.00017376    
0.00211835 0.00000006 0.00104825  0.25D+00   1808.91
    9  120   45    0    -614.26121765    -614.26689841 -0.00568076    
0.01223538 0.00001136 0.01069074  0.11D+01   2032.57
   10   90   48    0    -614.27429321    -614.28858580 -0.01429259    
0.04215226 0.00006428 0.00753717  0.97D+00   2281.39
   11   90   48    0    -614.29428392    -614.29664149 -0.00235757    
0.04543245 0.00000335 0.00118828  0.35D+00   2546.96
   12  100   45    0    -614.29674677    -614.29682755 -0.00008079    
0.00348054 0.00000006 0.00036145  0.15D+00   2792.74
   13   90   44    0    -614.29682976    -614.29683139 -0.00000164    
0.00085366 0.00000015 0.00004194  0.21D-01   3030.52
   14   90   23    0    -614.29683140    -614.29683140 0.00000000    
0.00003072 0.00000000 0.00000000  0.00D+00   3151.56

  ** WVFN ****  CONVERGENCE REACHED, FINAL GRADIENT:  0.31D-04

-- 
Univ.-Prof. Dr. Peter Burger
Institut fuer Anorganische und Angewandte Chemie
Universitaet Hamburg
Martin-Luther-King-Platz 6
D-20146 Hamburg
Tel.:+49 040 42838 3662
FAX                6097
email: burger at chemie.uni-hamburg.de
http://www.chemie.uni-hamburg.de/ac/burger/index.html

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.molpro.net/pipermail/molpro-user/attachments/20160525/e1729c27/attachment.html>