Stuck CCSD frequency calculation

Hello,

I am trying to run a frequency calculation on triazine using CCSD and the cc-pVDZ basis:

$molecule
0 1
N
C  1 1.342848
H  2 1.096982 1 116.734181
C  1 1.342848 2 113.468362 3 -180.000000 0
H  4 1.096982 1 116.734181 2 -180.000000 0
N  2 1.342848 1 126.531638 3 180.000000 0
N  4 1.342848 1 126.531638 2 0.000000 0
C  6 1.342848 2 113.468362 1 -0.000000 0
H  8 1.096982 6 116.734181 2 -180.000000 0
$end

$rem
JOBTYPE FREQ
METHOD CCSD
BASIS cc-pVDZ

MEM_TOTAL 256000
MEM_STATIC 2000
CC_BACKEND XM
CC_MEMORY 192000
CC_PRINT 7
$end

I had to increase the memory because the job initially was crashing with an out-of-memory error. However, now, it seems stuck, as the output has been like this for +15h:

  ----------------------------------------------------------------

             Standard Nuclear Orientation (Angstroms)

    I     Atom           X                Y                Z

 ----------------------------------------------------------------

    1      N       0.6924172271    -1.1993018173     0.0000000000

    2      C       1.2964999218     0.0000000000     0.0000000000

    3      H       2.3934819218     0.0000000000    -0.0000000000

    4      C      -0.6482499609    -1.1228018683     0.0000000000

    5      H      -1.1967409609    -2.0728161478     0.0000000000

    6      N       0.6924172271     1.1993018173    -0.0000000000

    7      N      -1.3848344541    -0.0000000000    -0.0000000000

    8      C      -0.6482499609     1.1228018683    -0.0000000000

    9      H      -1.1967409609     2.0728161478    -0.0000000000

 ----------------------------------------------------------------

 Molecular Point Group                 D3h   NOp = 12

 Largest Abelian Subgroup              C2v   NOp =  4

 Nuclear Repulsion Energy =         210.61506620 hartrees

 There are       21 alpha and       21 beta electrons

 Requested basis set is cc-pVDZ

 There are 45 shells and 99 basis functions

 Total memory of 256000 MB is distributed as follows: 

   MEM_STATIC is set to 2000 MB

   QALLOC/CCMAN JOB total memory use is  254000 MB

 Warning: actual memory use might exceed 256000 MB


 Total QAlloc Memory Limit 256000 MB

 Mega-Array Size      1956 MB

 MEM_STATIC part      2000 MB



                       Distance Matrix (Angstroms)

             N (  1)   C (  2)   H (  3)   C (  4)   H (  5)   N (  6)

   C (  2)  1.342848

   H (  3)  2.081333  1.096982

   C (  4)  1.342848  2.245604  3.242347

   H (  5)  2.081333  3.242347  4.145632  1.096982

   N (  6)  2.398604  1.342848  2.081333  2.681334  3.778316

   N (  7)  2.398604  2.681334  3.778316  1.342848  2.081333  2.398604

   C (  8)  2.681334  2.245604  3.242347  2.245604  3.242347  1.342848

   H (  9)  3.778316  3.242347  4.145632  3.242347  4.145632  2.081333

             N (  7)   C (  8)

   C (  8)  1.342848

   H (  9)  2.081333  1.096982

 

 A cutoff of  1.0D-14 yielded   1029 shell pairs

 There are      5049 function pairs (      5694 Cartesian)

 Smallest overlap matrix eigenvalue = 6.38E-03

 Guess from superposition of atomic densities

 Warning:  Energy on first SCF cycle will be non-variational

 SAD guess density has 42.000000 electrons


 -----------------------------------------------------------------------

  General SCF calculation program by

  Eric Jon Sundstrom, Paul Horn, Yuezhi Mao, Dmitri Zuev, Alec White,

  David Stuck, Shaama M.S., Shane Yost, Joonho Lee, David Small,

  Daniel Levine, Susi Lehtola, Hugh Burton, Evgeny Epifanovsky,

  Bang C. Huynh

 -----------------------------------------------------------------------

 Hartree-Fock

 using 12 threads for integral computing

 -------------------------------------------------------

 OpenMP Integral computing Module                

 Release: version 1.0, May 2013, Q-Chem Inc. Pittsburgh 

 -------------------------------------------------------

 A restricted SCF calculation will be

 performed using DIIS

 SCF converges when DIIS error is below 1.0e-08

 ---------------------------------------

  Cycle       Energy         DIIS error

 ---------------------------------------

    1    -280.7377427471      8.64e-02  

    2    -278.6159652340      8.38e-03  

    3    -278.6977459903      3.85e-03  

    4    -278.7131542312      8.07e-04  

    5    -278.7144498633      1.78e-04  

    6    -278.7145107011      5.94e-05  

    7    -278.7145252326      2.98e-05  

    8    -278.7145294287      9.99e-06  

    9    -278.7145300596      1.78e-06  

   10    -278.7145300757      2.51e-07  

   11    -278.7145300759      3.15e-08  

   12    -278.7145300759      3.84e-09  Convergence criterion met

 ---------------------------------------

 SCF time:   CPU 14.44s  wall 2.00s 

 SCF   energy in the final basis set =     -278.7145300759

 Total energy in the final basis set =     -278.7145300759



 ------------------------------------------------------------------------------


   CCMAN2: suite of methods based on coupled cluster

           and equation of motion theories.


   Components:

   * libvmm-1.3-trunk

     by Evgeny Epifanovsky, Ilya Kaliman.

   * libtensor-2.5-trunk

     by Evgeny Epifanovsky, Michael Wormit, Dmitry Zuev, Sam Manzer, 

        Ilya Kaliman.

   * libcc-2.5-trunk

     by Evgeny Epifanovsky, Arik Landau, Tomasz Kus, Kirill Khistyaev, 

        Dmitry Zuev, Prashant Manohar, Xintian Feng, Anna Krylov, 

        Matthew Goldey, Alec White, Thomas Jagau, Kaushik Nanda, 

        Anastasia Gunina, Alexander Kunitsa, Joonho Lee.


   CCMAN original authors:

   Anna I. Krylov, C. David Sherrill, Steven R. Gwaltney,

   Edward F. C. Byrd (2000)

   Sergey V. Levchenko, Lyudmila V. Slipchenko, Tao Wang,

   Ana-Maria C. Cristian (2003)

   Piotr A. Pieniazek, C. Melania Oana, Evgeny Epifanovsky (2007)

   Prashant Manohar (2009)


 ------------------------------------------------------------------------------



 Calculation will run on 12 cores using libxm for tensor contractions


 ------------------------------------------------------------------------------

Libxm Tensor Library

Copyright (c) 2014-2018 Ilya Kaliman

https://github.com/ilyak/libxm

Reference: https://dx.doi.org/10.1002/jcc.24713

 ------------------------------------------------------------------------------


 

 Alpha MOs, Restricted

 -- Occupied --                  

-15.591 -15.591 -15.591 -11.348 -11.348 -11.348  -1.358  -1.212

  1 E'    1 E'    1 A1'   2 E'    2 E'    2 A1'   3 A1'   3 E'                 

 -1.212  -0.926  -0.926  -0.753  -0.738  -0.606  -0.606  -0.604

  3 E'    4 E'    4 E'    4 A1'   1 A2'   5 E'    5 E'    1 A2"                

 -0.576  -0.438  -0.438  -0.434  -0.434

  5 A1'   6 E'    6 E'    1 E"    1 E"                                         

 -- Virtual --                   

  0.096   0.096   0.203   0.220   0.220   0.305   0.380   0.380

  2 E"    2 E"    6 A1'   7 E'    7 E'    2 A2"   8 E'    8 E'                 

  0.398   0.455   0.530   0.530   0.639   0.689   0.689   0.693

  7 A1'   2 A2'   9 E'    9 E'    3 A2"  10 E'   10 E'    8 A1'                

  0.715   0.715   0.751   0.751   0.903   0.913   0.913   0.930

  3 E"    3 E"   11 E'   11 E'    9 A1'  12 E'   12 E'    3 A2'                

  0.969   1.044   1.044   1.056   1.074   1.074   1.101   1.161

 10 A1'  13 E'   13 E'   11 A1'   4 E"    4 E"    4 A2"  14 E'                 

  1.161   1.205   1.234   1.307   1.307   1.323   1.362   1.362

 14 E'    5 A2"   1 A1"   5 E"    5 E"    4 A2'  15 E'   15 E'                 

  1.526   1.526   1.529   1.638   1.717   1.717   1.761   1.794

  6 E"    6 E"   12 A1'  13 A1'  16 E'   16 E'    5 A2'  17 E'                 

  1.794   1.894   1.909   1.909   1.988   1.988   2.033   2.159

 17 E'    6 A2"  18 E'   18 E'    7 E"    7 E"   14 A1'  19 E'                 

  2.159   2.374   2.374   2.403   2.403   2.447   2.496   2.536

 19 E'   20 E'   20 E'    8 E"    8 E"   15 A1'   6 A2'   9 E"                 

  2.536   2.553   2.553   2.654   2.929   2.929   2.932   3.013

  9 E"   21 E'   21 E'    7 A2"  22 E'   22 E'    2 A1"  16 A1'                

  3.072   3.072   3.236   3.246   3.246   3.546

 23 E'   23 E'    7 A2'  24 E'   24 E'   17 A1'                                

 

 Beta MOs, Restricted

 -- Occupied --                  

-15.591 -15.591 -15.591 -11.348 -11.348 -11.348  -1.358  -1.212

  1 E'    1 E'    1 A1'   2 E'    2 E'    2 A1'   3 A1'   3 E'                 

 -1.212  -0.926  -0.926  -0.753  -0.738  -0.606  -0.606  -0.604

  3 E'    4 E'    4 E'    4 A1'   1 A2'   5 E'    5 E'    1 A2"                

 -0.576  -0.438  -0.438  -0.434  -0.434

  5 A1'   6 E'    6 E'    1 E"    1 E"                                         

 -- Virtual --                   

  0.096   0.096   0.203   0.220   0.220   0.305   0.380   0.380

  2 E"    2 E"    6 A1'   7 E'    7 E'    2 A2"   8 E'    8 E'                 

  0.398   0.455   0.530   0.530   0.639   0.689   0.689   0.693

  7 A1'   2 A2'   9 E'    9 E'    3 A2"  10 E'   10 E'    8 A1'                

  0.715   0.715   0.751   0.751   0.903   0.913   0.913   0.930

  3 E"    3 E"   11 E'   11 E'    9 A1'  12 E'   12 E'    3 A2'                

  0.969   1.044   1.044   1.056   1.074   1.074   1.101   1.161

 10 A1'  13 E'   13 E'   11 A1'   4 E"    4 E"    4 A2"  14 E'                 

  1.161   1.205   1.234   1.307   1.307   1.323   1.362   1.362

 14 E'    5 A2"   1 A1"   5 E"    5 E"    4 A2'  15 E'   15 E'                 

  1.526   1.526   1.529   1.638   1.717   1.717   1.761   1.794

  6 E"    6 E"   12 A1'  13 A1'  16 E'   16 E'    5 A2'  17 E'                 

  1.794   1.894   1.909   1.909   1.988   1.988   2.033   2.159

 17 E'    6 A2"  18 E'   18 E'    7 E"    7 E"   14 A1'  19 E'                 

  2.159   2.374   2.374   2.403   2.403   2.447   2.496   2.536

 19 E'   20 E'   20 E'    8 E"    8 E"   15 A1'   6 A2'   9 E"                 

  2.536   2.553   2.553   2.654   2.929   2.929   2.932   3.013

  9 E"   21 E'   21 E'    7 A2"  22 E'   22 E'    2 A1"  16 A1'                

  3.072   3.072   3.236   3.246   3.246   3.546

 23 E'   23 E'    7 A2'  24 E'   24 E'   17 A1'                                


 Occupation and symmetry of molecular orbitals


 Point group: D3h (6 irreducible representations).


                           A1'  A2'  E'   A1"  A2"  E"    All 

 --------------------------------------------------------------

 All molecular orbitals:

  - Alpha                  17   7    48   2    7    18    99  

  - Beta                   17   7    48   2    7    18    99  

 --------------------------------------------------------------

 Alpha orbitals:

  - Frozen occupied        2    0    4    0    0    0     6   

  - Active occupied        3    1    8    0    1    2     15  

  - Active virtual         12   6    36   2    6    16    78  

  - Frozen virtual         0    0    0    0    0    0     0   

 --------------------------------------------------------------

 Beta orbitals:

  - Frozen occupied        2    0    4    0    0    0     6   

  - Active occupied        3    1    8    0    1    2     15  

  - Active virtual         12   6    36   2    6    16    78  

  - Frozen virtual         0    0    0    0    0    0     0   

 --------------------------------------------------------------


 Import integrals:   CPU 0.00 s  wall 0.00 s


 Import integrals:   CPU 20.68 s  wall 2.48 s


 MP2 amplitudes:   CPU 3.19 s  wall 1.33 s


Running a double precision version

           CCSD T amplitudes will be solved using DIIS.


           Start     Size      MaxIter   EConv     TConv     

           3         7         100       1.00e-07  1.00e-05  

 ------------------------------------------------------------------------------

           Energy (a.u.)   Ediff      Tdiff       Comment

 ------------------------------------------------------------------------------

          -279.56903478 

At this point, the job uses a single CPU (out of 12 assigned), but it won’t crash nor seem to continue. The starting geometry is the result of an optimisation I performed at the same level of theory, which ran smoothly in around 10 minutes. I have tried tweaking the memory around, changing the backend and using RI, but everything seems to end up at the same point.

Thanks in advance for any support!