Hello Bert,
Sorry to ask you again, but I have tried as you suggested me, however the program runs to a certain point and then it fails--> attached files
Moreover what I  noticed, was  when I used 
mpirun -np 2 ./nwchem file.nw > file.nwo &  it runs and crashes later
but with 
mpirun -np 1 ./nwchem file.nw > file.nwo &   it crashes immediately
Compiling nwchem-6.1.1 with openmpi-1.6.1 and with the newest blas library intel-mkl runs fine.
It seems there is a problem with bq; without bq, the program finished correctly! 
I'm not sure what goes wrong!
Greetings
Alfred 
P.S.: input & output
.......................... input
echo
start benzene_nics2
title "benzene nics2"
geometry
symmetry C1
 C   0.99   0.98  0.0 
........
bqH   0.0    0.0   0.0
end
basis "ao basis" spherical
c library 6-31g*
h library 6-31g*
bqH library H 6-31g*
end
dft
xc b3lyp
end
property
shielding 1  13
end
task dft property
............ output
         Chemical Shielding Tensors (GIAO, in ppm)
         -----------------------------------------
                               NWChem CPHF Module
                               ------------------
 scftype          =     RHF 
 nclosed          =       21
 nopen            =        0
 variables        =     1617
 # of vectors     =        3
 tolerance        = 0.10D-03
 level shift      = 0.00D+00
 max iterations   =       50
 max subspace     =       30
Integral file          = ./benzene_nics2.aoints.0
Record size in doubles =  65536        No. of integs per rec  =  43688
Max. records in memory =    185        Max. records in file   =  18347
No. of bits per label  =      8        No. of bits per value  =     64
#quartets = 7.491D+05 #integrals = 6.061D+06 #direct =  0.0% #cached =100.0%
File balance: exchanges=     1  moved=     4  time=   0.0
SCF residual:   7.90565231570597703E-005
Iterative solution of linear equations
 No. of variables     1617
 No. of equations        3
 Maximum subspace       30
       Iterations       50
      Convergence  1.0D-04
       Start time    120.4
  iter   nsub   residual    time
  ----  ------  --------  ---------
    1      3    5.56D-01     135.7
    2      6    9.42D-03     150.5
    3      9    8.53D-04     165.7
    4     12    2.99D-05     181.9
Parallel integral file used     140 records with       0 large values
hnd_giaox: geom_tag_to_element failed        0
------------------------------------------------------------------------
------------------------------------------------------------------------
------------------------------------------------------------------------
 current input line : 
    0: 
------------------------------------------------------------------------
------------------------------------------------------------------------
There is an error related to the specified geometry
------------------------------------------------------------------------
For more information see the NWChem manual at http://www.nwchem-sw.org/index.php/NWChem_Documentation
For further details see manual section:                                                                                                                                                                                                                                                                
1:1:hnd_giaox: geom_tag_to_element failed:: 0
(rank:1 hostname:nidorix pid:6965):ARMCI DASSERT fail. ../../ga-5-1/armci/src/common/armci.c:ARMCI_Error():208 cond:0
hnd_giaox: geom_tag_to_element failed        0
------------------------------------------------------------------------
------------------------------------------------------------------------
 current input line : 
   36: task dft property
------------------------------------------------------------------------
------------------------------------------------------------------------
There is an error related to the specified geometry[/quote]