[molpro-user] DF-LCCSD(T) problem: crash with larger basis set

[Jörg Saßmannshausen]

Dear all,

I am currently trying to perform some single point DF-LCCSD(T) calculations on 
an organometallic compound. 

At the DF-LCCSD(T)/cc-pVDZ level of theory, the calculation runs smooth 
without any problems and I get my single point energy.

However, when I am trying to run the same calculation at the DF-LCCSD(T)/cc-
pVTZ level, the calculation crashes in the CCSD part:
 Minimum memory for LCCSD:    38.40 MW, used:    200.00 MW, max:    389.90 MW

 ITER.      SQ.NORM     CORR.ENERGY   TOTAL ENERGY   ENERGY CHANGE        DEN1      
VAR(S)    VAR(P)  DIIS     TIME
   1      2.00665126    -2.99296600  -941.60036694     0.05725124    
-2.92306557  0.11D-01  0.16D-01  1  1  4454.17
   2      2.00663902    -5.22692889  -943.83432983    -2.23396289     
0.00001279  0.53D-03  0.65D+00  2  2  4521.51
   3      2.00603281    -5.22667989  -943.83408083     0.00024900     
0.00001475  0.57D-03  0.65D+00  3  3  4585.54
   4      2.00602946    -5.25966260  -943.86706354    -0.03298271     
0.00002130  0.10D-02  0.66D+00  4  4  4649.57
   5      2.00442950    -5.43585382  -944.04325475    -0.17619122     
0.00008619  0.55D-03  0.71D+00  5  5  4713.17
   6      2.00450932    -5.15168470  -943.75908563     0.28416912     
0.00002367  0.10D-02  0.65D+00  6  6  4780.77
   7  12750.36999404    -5.75382440  -944.36122534    -0.60213970     
0.47490011  0.73D-03  0.84D+00  6  1  4850.68

 UNREASONABLE NORM. CALCULATION STOPPED

 Norm of t1 vector:     13.76970764      S-energy:     0.00001516
 Norm of t2 vector:    112.07035801      P-energy:    -2.99387560

 ?ERROR: NO CONVERGENCE. TRIPLES WILL NOT BE DONE. THIS CAN BE AVOIDED USING 
THE NOCHECK OPTION.

 RESULTS
 =======
  LCCSD singles energy                 -0.003213334121
  LCCSD singlet pair energy            -2.848042961511
  LCCSD triplet pair energy            -3.097983757676
 
  LCCSD strong pair energy             -5.750611063722
  LMP2 close pair energy               -0.110540018435
  LMP2 weak pair energy                -0.082516374676
  LMP2 distant pair energy             -0.002359262354
 
 
  Reference energy                   -938.607400937737
 
  LCCSD correlation energy             -5.949240053308
 !LCCSD total energy                 -944.556640991046

 Program statistics:

 Available memory in ccsd:           198929165
 Min. memory needed in ccsd:          38401396
 Max. memory used in ccsd:           199999901
 
 ? Error
 ? No convergence. This error exit can be avoided using the NOCHECK option
 ? The problem occurs in ccsd_loc

My input file is like that (minus the coordinates):
memory,200,m    
SET,CHARGE=1    !charge of the molecule is +1
! SET,ZSYMEL=NOSYM ! turn off symmetry
geomtyp=xyz
geometry
   45
[ ... ]
gdirect                    !direct calculations
hf,maxit=300
hf,direct
basis=cc-pVTZ              !cc-pVTZ basis set for all elements
hf                         !Perform HF calculation
DF-lccsd(t)                !Perform L-CCSD(T) calculation with density fitting


I am currently trying to run a pure LCCSD with the same basis set but I was 
running out of scratch space. :-(

Is there something wrong with my input or is there a 'problem' with the 
molecule. The geometry has been calculated at the M11/6-311G(d,p) level of 
theory and a frequency calculation indicates a minimum on the PES. However, I 
got to admit, I am not really trusting the DFT calculations here and hence the 
CCSD(T) calculation. It is a closed shell compound with Al as the metal. 

Does anybody got an idea here? 

All the best from a cold London

Jörg

-- 
*************************************************************
Jörg Saßmannshausen
University College London
Department of Chemistry
Gordon Street
London
WC1H 0AJ 

email: j.sassmannshausen at ucl.ac.uk
web: http://sassy.formativ.net

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