tce mrcc readref


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Hi,

I'm giving the MRCC capability of TCE a try. I've set up a job configured with

           General Information
-------------------
Number of processors : 144
Wavefunction type : Restricted open-shell Hartree-Fock
No. of electrons : 240
Alpha electrons : 120
Beta electrons : 120
No. of orbitals : 3234
Alpha orbitals : 1617
Beta orbitals : 1617
Alpha frozen cores : 108
Beta frozen cores : 108
Alpha frozen virtuals : 1350
Beta frozen virtuals : 1350
Spin multiplicity : singlet
Number of AO functions : 1620
Number of AO shells : 504
Use of symmetry is : on
Symmetry adaption is : on
Schwarz screening : 0.10D-09

The idea is to freeze 90% of the lowest occupied and highest virtual orbitals, and look at memory requirements as I successively unfreeze more. As configured, the reference active space should be (4,4), and the CC active space should have 1617-1350-108 = 159 orbitals and (0.1*120 - 4/2) = 10 electrons outside of the reference active space, for each spin manifold.

The input mrccdata information looks like
mrccdata
  root 2
  cas 4 4
  subgroupsize 4
  improvetiling
end

Per the documentation, the subgroupsize was set based on 36 references and 144 MPI ranks --> 144/36 = 4.
I can understand the error from the output, but I don't know what the output is telling me:
  !! WARNING !! The number of MO is less than the number of AO

          Correlation Information
          -----------------------
          Calculation type : State Specific Multireference Brillouin-Wigner CCSD theory
   Perturbative correction : none
            Max iterations :      100
        Residual threshold : 0.10D-06
     T(0) DIIS level shift : 0.00D+00
     L(0) DIIS level shift : 0.00D+00
     T(1) DIIS level shift : 0.00D+00
     L(1) DIIS level shift : 0.00D+00
     T(R) DIIS level shift : 0.00D+00
     T(I) DIIS level shift : 0.00D+00
   CC-T/L Amplitude update :  5-th order DIIS
                I/O scheme : Global Array Library

Active elec :   4
Active orbs :   4


Alpha 1100
Beta  1100

Total no. of references:    0</b>

MRCC module - reference analysis

Fermi vacuum according to SCF wave function  has been requested.
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 tce_mrcc_readref                   3
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So, it seems like there are no "references" (I assume this is the CAS part of the calculation), but the calculation identified the active space correctly. I also don't know what the "1100" numbers mean for alpha and beta.

Any clues?

Thanks; Chris