Re: [AMBER] QMMM SCC-DFTB: ERROR ON EWEVGE (Eigenvalue solver)

From: Brian Radak <radak004.umn.edu>
Date: Tue, 15 Nov 2011 08:49:51 -0500

Emmanuel,

This is perhaps obvious and therefore not too helpful, but whenever I get
such errors (although I primarily use NDDO methods) I first double check
that my system charge is correct and then visualize the system to ensure
that the starting point is reasonable. I've never used the QM/GB options
before, does a gas phase calculation give the same error?

Regards,
Brian

On Mon, Nov 14, 2011 at 6:39 PM, Emmanuel Baribefe Naziga <
baribefe.gmail.com> wrote:

> Hello everyone,
>
> I am having some errors with DFTB calculation and I am hoping to get some
> pointers on how to solve this problem.
>
> My input file is as follows:
>
> DFTB GB minimization
> &cntrl
> imin =1,irest=0,
> maxcyc=10000,ncyc=100,
> ntpr=1,
> ntb=0, cut=999.,
> ntt=0,
> ifqnt=1,
> ntwx = 10,
> igb=1
> /
> &qmmm
> qmmask=':*'
> qm_theory='DFTB',
> tight_p_conv=0,
> scfconv=1.0d-8,
> qmcharge=0,
> printcharges=0,
> dftb_disper=0,
> dftb_chg=0,
> dftb_maxiter=70,
> qmgb=2,
> qmshake=0,
> writepdb=1
> /
>
> I keep getting error messages like:
> NSTEP ENERGY RMS GMAX NAME NUMBER
> 1879 -5.1187E+03 4.9065E-02 2.0210E-01 C2 19
>
> BOND = 0.0000 ANGLE = 0.0000 DIHED =
> 0.0000
> VDWAALS = 0.0000 EEL = 0.0000 EGB =
> -33.5978
> 1-4 VDW = 0.0000 1-4 EEL = 0.0000 RESTRAINT =
> 0.0000
> DFTBESCF= -5085.0779
>
> QMMM SCC-DFTB: ***************************************************
> QMMM SCC-DFTB: ERROR ON EWEVGE (Eigenvalue solver).
> QMMM SCC-DFTB: ewevge: ier = 118 inner_scf_count= 1
> QMMM SCC-DFTB: ***************************************************
>
> QMMM SCC-DFTB: !!!! ============= WARNING ============= !!!!
> QMMM SCC-DFTB: Convergence could not be achieved in this step.
> QMMM SCC-DFTB: The calculation will continue, but energies and
> QMMM SCC-DFTB: forces for this step will not be accurate.
>
> QMMM SCC-DFTB: ***************************************************
> QMMM SCC-DFTB: ERROR ON EWEVGE (Eigenvalue solver).
> QMMM SCC-DFTB: ewevge: ier = 118 inner_scf_count= 2
> QMMM SCC-DFTB: ***************************************************
>
>
> which finally ends in NaNs in most cases.
>
> Thanks for your advice.
>
> Emmanuel
> _______________________________________________
> AMBER mailing list
> AMBER.ambermd.org
> http://lists.ambermd.org/mailman/listinfo/amber
>



-- 
================================ Current Address =======================
 Brian Radak                                             :     BioMaPS
Institute for Quantitative Biology
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 radak004.umn.edu                                 :
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Received on Tue Nov 15 2011 - 06:00:03 PST
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