CCSD Converge issue for large CCSD(T) Jobs


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Hello,

  I am running a big CCSD(T) job for a molecule with aQ basis set with 1500 basis function.
This jobs is running with CCSD Rendell mode.

 After 9 iterations, I didn't see the trend to converge?

 The output shows 


000: -------------------------------------------------------------------------
000: g_st2 size: 19855 MB
000: mem. avail 24874 MB
000: Memory based method: ST2 is allocated
000: ST2 array is replicated 22.70s
000: 1 -3.6891868857 -3.689D+00 1.919D+00 7455.20 0.39 6850.36
000: g_st2 size: 19855 MB
000: mem. avail 24874 MB
000: Memory based method: ST2 is allocated
000: ST2 array is replicated 17.75s
000: 2 -4.3190404223 -6.299D-01 1.704D+01 7453.07 0.19 6854.97
000: g_st2 size: 19855 MB
000: mem. avail 24874 MB
000: Memory based method: ST2 is allocated
000: ST2 array is replicated 18.16s
000: 3 -4.1344811774 1.846D-01 1.129D+02 7454.94 0.24 6859.16
000: g_st2 size: 19855 MB
000: mem. avail 24874 MB
000: Memory based method: ST2 is allocated
000: ST2 array is replicated 18.22s
000: 4 -4.1121806442 2.230D-02 6.161D+01 7428.63 0.28 6832.03
000: g_st2 size: 19855 MB
000: mem. avail 24874 MB
000: Memory based method: ST2 is allocated
000: ST2 array is replicated 18.44s
000: 5 -4.0803335589 3.185D-02 1.953D+00 7447.44 0.36 6848.48
000: g_st2 size: 19855 MB
000: mem. avail 24874 MB
000: Memory based method: ST2 is allocated
000: ST2 array is replicated 18.31s
000: 6 -4.0773754084 2.958D-03 5.405D+00 7450.44 0.33 6851.98
000: g_st2 size: 19855 MB
000: mem. avail 24874 MB
000: Memory based method: ST2 is allocated
000: ST2 array is replicated 18.00s
000: 7 -3.9549254913 1.224D-01 1.218D+00 7447.27 0.33 6850.51
000: g_st2 size: 19855 MB
000: mem. avail 24874 MB
000: Memory based method: ST2 is allocated
000: ST2 array is replicated 18.13s
000: 8 -4.2142074686 -2.593D-01 2.760D+01 7460.35 0.34 6864.15
000: g_st2 size: 19855 MB
000: mem. avail 24874 MB
000: Memory based method: ST2 is allocated
000: ST2 array is replicated 17.96s
000: 9 -4.2827471224 -6.854D-02 2.308D+02 7452.48 0.33 6852.47
000: g_st2 size: 19855 MB
000: mem. avail 24874 MB




Is it normal ?

Is there something I can do to fix this issue ?

By the way, this molecule has a symmetry of C4V, while symmetry can not be used for CCSD Calculation.

Thanks a lot.


Zongtang


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