[gmx-users] zirconia

[David van der Spoel]

pushyami atluri wrote:
> hello,
>  i am trying to simulate zirconia using buckhingham potentials but i get 
> nan values for energies and also in the confout file.i would like to 
> know if anybody has succeeded in simulating metallic systems with buck 
> potentials because i came across this mailing list which talks about a 
> problem being there with t code regarding the exponential term in buck 
> potentials.please help

You have very large charges. Where does this potential come from? What 
is the distance between atoms? If this is a bonded system then you can 
not have such strong interactions at short distances.

> here is my top file
> please take some time to take a look in case i am goin wrong with t file
> ;topology file
> [ defaults ]
>   2                            
> [ atomtypes ]
> ;name        mass      charge   ptype            c6           c12
>    OX        15.99940     -2.0     A  21.95e+05  0.01490  2.691e-03
>    ZR        91.22420      4.0     A  0.0000000  1.00000  0.0000000
> [ nonbond_params ]
>   ; i    j func           a             b    c6
>    OX   OX    2    21.95e+05       0.01490       2.691e-03
>    ZR    OX    2    9.512e+04       0.03760       0.0000000
>    ZR   ZR    2    0.0000000       1.00000       0.0000000
> [ moleculetype ]
>  ZR 0
>  
> [ atoms ]
> 1        ZR     1        DP      ZR      1      4.0      91.22420
>  
> [ moleculetype ]
>  OX 0
>  
> [ atoms ]
> 1        OX      1       DP      OX      2      -2.0     15.99940
>  
> [ system ]
> ZIRCONIA
>  
> [ molecules ]
> ZR 2000
> OX 4000
>  
> thanking you
> 
> pushyami atluri
> 
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-- 
David.
________________________________________________________________________
David van der Spoel, PhD, Assoc. Prof., Molecular Biophysics group,
Dept. of Cell and Molecular Biology, Uppsala University.
Husargatan 3, Box 596,  	75124 Uppsala, Sweden
phone:	46 18 471 4205		fax: 46 18 511 755
spoel at xray.bmc.uu.se	spoel at gromacs.org   http://folding.bmc.uu.se
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