NEB QM/MM calculation. Topology error
Just Got Here
5:40:01 AM PST - Thu, Feb 19th 2015
Hello!
I was attempting to run NEB/QMmm calculations and made an input file just as it is in the example (ClOH), but my system is much more bigger (93 qm atoms and 6561 mm atoms (protein and water molecules)). The calculation stops with such an error^

0: Error opening topology file 2

The file exists and is named after the system's name. The error occures before .cmd and .out file for the xyz_end.rst (end NEB point) are written. I have tried to increase the msa up to 512000. But that didn\t give any positive results.

Could anyone help me, please?

Thanks in advance
Kate

Just Got Here
1:59:55 AM PDT - Tue, Jun 23rd 2015
there is two possible reasons,one is your topology file is error another you input is error leading to error read topology file
Hi,
  I'm having some trouble running a QM/MM optimization on a system of a large protein.
I just simplify it into a smaller system that ATP interacted with the surrounding of the residues.I define the ATP segment as qm region and the rest as mm region.
  First,I take a task of prepare

 

  Here is the input file,pre.nw:

permanent_dir ./perm
scratch_dir ./data

charge -2

prepare
source atp.pdb
new_top new_seq
new_rst
center
orient
modify segment 952 quantum
update lists
ignore
write reac_ref.rst
write reac_ref.pdb
end

task prepare

   Then, I use the reac.top and reac_ref.rst files obtaining from the prepare task to make optimization.I possibility set some parameters smaller so that it can quickly verify.

   

   The input file of optimization is showing below,opt.nw:
start reac

permanent_dir ./perm
scratch_dir ./data
md
system reac_ref
end

basis
  • library "6-31G"
end

dft
xc b3lyp
end

qmmm
bqzone 20.0
region qm mm
maxiter 10 1000
ncycles 2
density espfit
xyz foo
end

task qmmm dft optimize

prepare
read reac_ref.rst
write reac_opt.pdb
end

task prepare



The errors in the output file like this:

 Memory utilization after 1st SCF pass: 

          Heap Space remaining (MW):        0.00                   0

         Stack Space remaining (MW):       12.99            12989676



  convergence    iter        energy       DeltaE   RMS-Dens  Diis-err    time

---------------- ----- ----------------- --------- --------- ---------  ------

d= 0,ls=0.0,diis     1  -2625.3970221245 -6.58D+03  1.64D+01  1.78D+01   216.4

Nuclear repulsion energy =   3949.30625746002     

Bq nuclear interaction energy =   5.09231130369664     

WARNING: error on integrated density =  0.11D-05

greater than required accuracy of  0.10D-05

d= 0,ls=0.5,diis     2  -2282.8510692315  3.43D+02  4.07D+00  9.39D+02   247.5

Nuclear repulsion energy =   3949.30625746002     

Bq nuclear interaction energy =   5.09231130369664
.................


Forum >> NWChem's corner >> QMMM