CASPT2 problem occurs in cirs2ii

[Li Yuan]

Dear Molpro experts,

I am trying to run a CASPT2 calculation with Molpro 2025.3. The relevant input block for CASPT2 setting is:

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max_iter = 8
real         = 0.20
value      = 0.25

{ rs2, shift=real, IPEA=value, MIX=5, MAXIT=max_iter, nocheck;
  OCC,  120; CLOSED, 89
  CORE, 89
  ORBITAL, 2220.2, IGNORE_ERROR
  restrict, 9, 9, 90.1, 91.1, 92.1, 93.1, 94.1;
  restrict, 1, 3, 119.1, 120.1;
  WF, 236, 1, 2
  state,      1
!!  NOEXC !!
  SAVE,5161.2
}

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

 

The calculation failed with error:

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 A level shift of 0.20 is applied.

  ITER. STATE  ROOT     SQ.NORM     CORR.ENERGY   TOTAL ENERGY   ENERGY CHANGE       DEN1      VAR(S)    VAR(P)      TIME
    1     1     1     1.53362949    -0.10672590-16107.94572265    -0.10672590    -0.85600838  0.53D+00  0.30D+00   321.97

 ? Error
 ? noref, ov
 ? The problem occurs in cirs2ii

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I appreciate if anyone can help me find a workaround or fix this issue. I attach the input and output files for your review.  Thank you.

Best regards,

Lei