Kanin,
This may not be the specific cause of your error, but AMBER/SQM is not
compatible with DFTB3 type Hamiltonians. Only the "pseudo third order"
methods are implemented (and unfortunately these are generally not as good
as the newer parameterizations like 3ob).
Depending on your application I would look for a suitable NDDO method (AM1
or PM6 type) or else determine if SCC-DFTB (DFTB2) is adequate.
Regards,
Brian
On Tue, Jan 14, 2014 at 9:24 AM, Kanin Wichapong
<kanin.wichapong.gmail.com>wrote:
> Dear Amber Users,
>
> I tried to set up QM/MM calculation using scc-dftb method. I downloaded the
> scc-dftb parameters (3ob set) from the dftb website (www.dftb.org).
> However, I got an error about Eigenvalue solver during the calculation.
>
> Here is my input:
>
> Minimization ENTIRE COMPLEX ---
>
> &cntrl
>
> imin = 1,
>
> maxcyc = 5000,
>
> ncyc = 2500,
>
> ntb = 1,
>
> ntr = 0,
>
> cut = 8
>
> ifqnt = 1
>
> /
>
> &qmmm
>
> qmmask=":42,191,266,267,397 ",
>
> qm_theory='DFTB',
>
> dftb_disper=1,
>
> dftb_chg=1,
>
> tight_p_conv=1,
>
> scfconv=1.0d-8,
>
> qm_ewald=1,
>
> qmcharge=2,
>
> /
>
> The QM region includes Ser, His, Water (protein), and Arg-Lys (substrate).
>
>
> Here is the error:
>
> *NSTEP ENERGY RMS GMAX NAME NUMBER *
>
> *1 -2.6303E+05 2.5691E+00 1.4419E+02 NZ 4186 *
>
> *BOND = 20291.2616 ANGLE = 1875.4936 DIHED = 6004.3320 *
>
> *VDWAALS = 51206.9170 EEL = -347214.0714 HBOND = 0.0000 *
>
> *1-4 VDW = 1303.0030 1-4 EEL = 12384.0272 RESTRAINT = 0.0000 *
>
> *DFTBESCF= -8884.5851 *
>
> *QMMM SCC-DFTB: *************************************************** *
>
> *QMMM SCC-DFTB: ERROR ON EWEVGE (Eigenvalue solver). *
>
> *QMMM SCC-DFTB: ewevge: ier = 193 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. *
>
> I also tried not to include water in the QM region, but I still got the
> same error. However, if I used other QM methods (AM1, PM3 or PM6), the
> calculation was fine, no error. I found in the amber-mailing list that
> somebody also had the same problems as me but there were no clear solutions
> to solve this problems on that time.
>
>
> I hope that somebody can help me to solve this problems.
>
>
> Best Regards and Thank you so much in advance,
>
> Kanin Wichapong
> _______________________________________________
> AMBER mailing list
> AMBER.ambermd.org
> http://lists.ambermd.org/mailman/listinfo/amber
>
--
================================ Current Address =======================
Brian Radak : BioMaPS
Institute for Quantitative Biology
PhD candidate - York Research Group : Rutgers, The State
University of New Jersey
University of Minnesota - Twin Cities : Center for Integrative
Proteomics Room 308
Graduate Program in Chemical Physics : 174 Frelinghuysen Road,
Department of Chemistry : Piscataway, NJ
08854-8066
radak004.umn.edu :
radakb.biomaps.rutgers.edu
====================================================================
Sorry for the multiple e-mail addresses, just use the institute appropriate
address.
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Received on Tue Jan 14 2014 - 07:00:03 PST
