Hi,
Try OPT=LBFGS rather than OPT=BFGS. That should eliminate the problem.
Kennie
On Jul 14, 2004, at 11:33 AM, steven.j.enoch.gsk.com wrote:
>
> Amber users,
>
> I am trying use antechamber to create prep (and frcmod) files for a
> large ligand (126 atoms). It is essentially two protien chains linked
> together by an organic backbone. When I run antechamber I get the
> following error message:
>
> CARTESIAN AM1 STANDARD DIRECT OPT=BFGS XTEST=0.0001 CHARGE=-3
>
>
> created by wmopcrt()
>
>
>
> CARTESIAN - CARTESIAN COORDINATE FORMAT SELECTED
> AM1 - AM1 HAMILTONIAN TO BE USED
> STANDARD - STANDARD CLOSED-SHELL CALCULATION (NO D&C)
> DIRECT - DO NOT STORE 2-ELECTRON INTEGRALS IN SCF CALCULATIONS
> OPT=BFGS - CARRY OUT A BFGS GEOMETRY OPTIMIZATION
> XTEST=0.0001 - GEOMETRY OPTIMIZATION COORDINATE CHANGE CRITERION =
> 0.00010
> CHARGE=-3 - A NET CHARGE OF -3.00 TO BE PLACED ON SYSTEM
>
>
> NUMBER OF ATOMS = 124
> TOTAL NUMBER OF BASIS FUNCTIONS = 313
> TOTAL NUMBER OF ELECTRONS = 352
>
>
> DEFAULT SETTINGS FOR CALCULATION
> --------------------------------
>
> - D&C TEMPERATURE OF 1000.00 K WILL BE USED
> - NO TIME LIMIT ON CALCULATION
>
>
> ETEST = 0.002000
> XTEST = 0.000100
> GNTEST = 2.410913
> GTEST = 0.500000
>
> NUMBER OF VARIABLES= 372
>
> UPDATING PAIRLIST
> NPAIRS = 7626
>
> CYCLE = 0 TIME = 47.565 ENERGY = -405.624288
> GNORM = 473.513 GRDMAX = 114.8450 GRDAVR = 17.6764
> DELTAE = 0.000000 DELTAX = 0.000000
>
> MAXIMUM NUMBER OF ATOMS IN BFGS SEARCH EXCEDEED
>
> Max Degree = 180 NPAR= 372
>
> INCREASE MXATTS IN divcon.dim AND RECOMPILE
>
>
> FINAL QUANTITIES:
> -----------------
>
> NUMBER OF FULLY DIAGONALIZED SUBSYSTEMS: 1
> NUMBER OF FROZEN SUBSYSTEMS: 0
> NUMBER OF SCF CALCULATIONS = 1
>
> ELECTRONIC ENERGY = -143107.91168290 EV
> CORE-CORE REPULSIONS = 130880.02283529 EV
> TOTAL ENERGY = -12227.88884761 EV
> HEAT OF FORMATION = -405.62428815 KCAL/MOL
> FERMI ENERGY = 0.00000000 EV
>
>
> I have tried increasing MXATTS to 150 (and then 400) and then
> recompiled divcon, but I still get the same error message. Does
> anybody have any advice on how to get around this problem? Or can
> divcon not deal with such a large ligand?
>
> Many thanks
>
> Dr Steve Enoch
> GlaxoSmithKline
> UK
Professor Kenneth M. Merz, Jr.
152 Davey Laboratory
Department of Chemistry
The Pennsylvania State University
University Park, Pennsylvania 16802
e-mail: merz.psu.edu
http: http://merz.chem.psu.edu
QBio DB: http://qbiodb.chem.psu.edu
Phone: 814-865-3623
FAX: 814-863-8403
Cell: 814-360-0376
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Received on Wed Jul 14 2004 - 17:53:01 PDT
