Hi,
I am running qmmm calculations using AM1D. The system of interest is a
kinase with one atp molecule and two magnesium cations within a protein
environment. The QM region includes the atp molecule, magnesium cations and
side chain of a threonine, a aspartic and a lysine.
Both in optimization and MD each atom of the QM region starts to move away
from each other. When I did this same thing using DFTB that problem did not
happen.
Also, the mdout show the next message in both optimization and MD.
QMMM: WARNING!
QMMM: Unable to achieve self consistency to the tolerances specified
QMMM: No convergence in SCF after 2000 steps.
QMMM: Job will continue with unconverged SCF. Warning energies
QMMM: and forces for this step will not be accurate.
QMMM: E = -0.8693E+06 DeltaE = -0.5769E+03 DeltaP = 0.1544E+01
QMMM: Smallest DeltaE = 0.3633E-01 DeltaP = 0.1045E+01 Step = 210
In the optimization this message is not showed if i use the keywords
ndiis_attempts=50 ndiis_matrices=10. However the QM structure continue
destroying itself in the optimization.
I attach the mdin file for the optimization.
Thanks in advance.
Gabriel
--
Dr. Gabriel E. Jara
INQUIMAE - CONICET
Facultad de Ciencias Exactas y Naturales
Universidad de Buenos Aires
--
Dr. Gabriel E. Jara
INFIQC - CONICET
Departamento de Química Orgánica
Facultad de Ciencias Químicas
Universidad Nacional de Córdoba
Tel: ++54-351-4334170/4173 int. 132
Fax: ++54-351-4333030
X5000HUA - Córdoba -Argentina
_______________________________________________
AMBER mailing list
AMBER.ambermd.org
http://lists.ambermd.org/mailman/listinfo/amber
Received on Thu May 03 2012 - 15:30:03 PDT
