[Molpro-user] Segmentation fault with FCI

[Kirk Peterson]

Dear Lorenzo,

In the latest version of the program (2008.1) the program ends  
"gracefully" with a insufficient memory available error.  This  
calculation
involves a very large number of determinants.  The formatting is also  
blown out for C2v symmetry.  Even with just the cc-pVDZ basis set
the FCI has over 39 million determinants in each irrep (in Cs).

regards,

Kirk

On Oct 1, 2008, at 5:27 AM, Lorenzo Lodi wrote:

> I tried to run a frozen-core full-CI calculation on water in a Cs
> geometry using the aug-cc-pVDZ basis set.
> The machine used was a 3.4GHz Pentium IV PC with 3GB of ram; I used
> MOLPRO 2006.1 under Linux 32bit.
> The input is as follows:
>
> ***, Calculation FCI of water
> MEMORY, 250, M
> r1=1.81, r2=2.00, theta=104.5
> geometry={O;  H1,O,r1;  H2,O,r2,H1,theta}
> basis=aug-cc-pVDZ
> {RHF}
> FCI
>
> The computation stopped after 6.6h with this error:
>
> 0Hamiltonian diagonaliser entered at time      0.83
> Received signal 11 Segmentation violation
>
> I was monitoring the memory usage using top and at the moment of the
> crash it was of exactly 1GB. As I had given MOLPRO 2GB this doesn't
> immediately strike me as an error due to lack of memory.
>
> Searching the user forum archive with the keywords <FCI segmentation>
> finds two threads ("FCI calculation for H3" and "error in molpro")  
> which
> may describe similar (or identical) problems.
> I could not read these messages because the links given by the search
> engine do not work (they used to in the past), and furthermore it is
> apparently not possible (any more) to see the whole list of past
> messages (whatever happened to the archive web site?!)
>
> Lorenzo Lodi
>
> NB: in the FCI program the number of determinants is just a string of
> asterisks:
>  Strings:                       46411   44979       0       0       0
>      0       0       0
>                                 46411   44979       0       0       0
>      0       0       0
>  Determinants:               ****************       0       0       0
>      0       0       0
>
>  Load integrals                0.3 sec
>
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