[Molpro-user] Segmentation fault with FCI

Lorenzo Lodi l.lodi at ucl.ac.uk
Wed Oct 1 13:27:27 BST 2008

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}

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 
  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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