Question about qmmm calcualtions


Click here for full thread
Just Got Here
4:56:20 PM PDT - Mon, May 16th 2011
Hi, NWchem users,

I am a beginner of NWCHEM program. I am trying to do some qmmm calculations for a cluster composed of a number of molecules. I found that if the cluster include 7 molecules (defined as seven segments), the calculation runs well. However, for larger cluster including more than 7 segments, I always got a error message saying " bgj_get_scf_method: error reading rtdb 1" . Below is my input file. I would be very appreciated if you have any suggestions for this problem.

Roy


Title "NPT-amber vdW"

start 

 permanent_dir .

 scratch_dir .

prepare
system red_ref

source eim.pdb

new_top new_seq
  1. periodic
  2. box 4.0 4.0 4.0
 modify segment 1  quantum
  1. modify atom 1:1FB quantum
  2. modify atom 1:2FB quantum
  3. modify atom 1:3FB quantum
  4. modify atom 1:4FB quantum
  5. modify atom 1:1BF quantum
  6. center
  7. orient
  8. update lists
  9. ignore
write red_ref.rst

write red_ref.pdb
end
task prepare

task shell "cp red_ref.rst red_qmmm.rst"

md
system red_qmmm

noshake solute
end

basis
* library "6-31g"
end

dft
xc b3lyp
end

qmmm
region all
  1. maxiter 5 5 5
  2. ncycles 3
density espfit
end

task qmmm dft energy