[molpro-user] Error in atomic MRCI calculation

[Jacek Antoni Klos]

Hi Lorenzo, 

Yes, with this larger input the NaNs and infinities appear for single and parallel execution, both on Mac and PC-Linux platforms with 2012.1/intel/mkl. 
Let me note, that these infinities appear only for the part of your input where you do 9-state MRCI. I think
you need to extend active space in this case, try to put OCC,11 and the infinities will disappear.   

 
Best
Jacek 



On Oct 17, 2013, at 11:29 AM, Lorenzo Lodi <l.lodi at ucl.ac.uk> wrote:

> On 17/10/13 16:05, Jacek Antoni Klos wrote:
>> Hi Lorenzo, 
>> 
>> I ran your input and I don't observe any infinities if I use single CPU. 
>> 
>> However when I ran this input with 2 or more CPUS in parallel, there are infinities in the output as you 
>> observe. I used 2012.1.   
> 
> Thank you for your feedback, Jacek! I ran my input again with versions
> 2012 and 2010 compiled with gcc or intel compiler and I have infinities
> in all cases (actually, the molpro2012/intel combination gives me a
> segmentation fault error at CASSCF but this is not related with this
> specific input, anyway).
> I attached a larger input which also has these infinities and NaNs (runs
> in ~1 second).
> 
> Lorenzo
> 
> 
>> 
>> On Oct 17, 2013, at 9:34 AM, Lorenzo Lodi <l.lodi at ucl.ac.uk>
>> wrote:
>> 
>>> Consider the following minimalist calculation for the 3P ground term of
>>> Ar++:
>>> 
>>> *** Calculation for Ar++
>>> 
>>> basis={default, cc-pVDZ}
>>> NOSYM
>>> geometry={Ar}
>>> 
>>> {CASSCF; OCC, 9; CLOSED,5; FROZEN,0; WF, elec=16, sym=1,spin=2;state,3;}
>>> {MRCI    ; OCC, 9; CLOSED,5; CORE,5; WF, elec=16, sym=1,spin=2;state,3; }
>>> 
>>> CASSCF runs without problems and gives E=-526.817022986694.
>>> MRCI also runs and gives a MRCI energy E=-526.92881183. However, in many
>>> places I get `infinities', e.g.:
>>> 
>>> 
>>> 
>>> Energy contributions of singly external configurations for state 1
>>> ==================================================================
>>> 
>>>  NUMBER        NORM          ECORR1        OCCUPATION
>>> 
>>>    1       0.00000000      -Infinity      
>>> 1022                           
>>>    2       0.00000000      +Infinity      
>>> 0122                           
>>>    5       0.00236458      -Infinity      
>>> 1220                           
>>> 
>>> 
>>> Energy contributions of configuration classes
>>> 
>>> CLASS          SQ.NORM        ECORR1        ECORR2
>>> +++++++++++++++++++++++++++++++++++++++++++++++++++
>>> Internals     +Infinity           NaN           NaN
>>> Singles       +Infinity     -Infinity           NaN
>>> Pairs         +Infinity     +Infinity           NaN
>>> Total         +Infinity           NaN           NaN
>>> +++++++++++++++++++++++++++++++++++++++++++++++++++
>>> 
>>> 
>>> Reference energy                    -526.81702299
>>> Nuclear energy                         0.00000000
>>> Kinetic energy                       525.51796052
>>> One electron energy                 -711.13604804
>>> Two electron energy                  184.20723620
>>> Virial quotient                       -1.00268469
>>> Correlation energy                    -0.11178885
>>> !MRCI STATE 1.1 Energy              -526.928811837479
>>> 
>>> !MRCI STATE 1.1 Dipole moment          0.00000000     0.00000000    
>>> 0.00000000
>>> Dipole moment /Debye                   0.00000000     0.00000000    
>>> 0.00000000
>>> 
>>> Cluster corrected energies              -Infinity (Davidson, fixed
>>> reference)
>>> Cluster corrected energies          -526.93344888 (Davidson, relaxed
>>> reference)
>>> Cluster corrected energies          -526.93344888 (Davidson, rotated
>>> reference)
>>> 
>>> 
>>> 
>>> If I do the MRCI calculation for one state only I obtain slightly larger
>>> energies (E(MRCI)=-526.928597650037) but no `infinities' in the output.
>>> What causes this problem? Is it because I'm running without point-group
>>> symmetry?
>>> 
>>> Any input would be appreciated :)
>>> 
>>> Regards,
>>> Lorenzo
>>> 
>>> _______________________________________________
>>> Molpro-user mailing list
>>> Molpro-user at molpro.net
>>> http://www.molpro.net/mailman/listinfo/molpro-user
>> 
> 
> <argon_plus_plus.inp>