[DFTB-Plus-User] Pressure in DFTB

Ben Hourahine benjamin.hourahine at strath.ac.uk
Fri Jun 13 18:26:59 CEST 2014


Hello Rajak,

the pressure you obtained is fairly typical for that level of force
tolerance. Depending on the physical system you are interested in, this
value may not be excessive for correct prediction of properties, but as
always the correct procedure is to test the effect of changing the
simulation parameters. You are correct that reducing the level of the
force tolerance will reduce the pressure towards 0 (a tolerance of  <
1e-8 or lower is probably required to get below 1 atmosphere though).

Regards

Ben


On 09/06/14 09:21, rajak rajak wrote:
> Dear Sir,
> 
> I am new to DFTB software. Recently, I am using DFTB+ to optimize the
> structure of GaAs. However, the pressure after the calculation converge is
> very large, on the order of 10e9 Pa. I set the convergence criteria of
> force to 1e-4 and use latticeopt. Does that mean I need to use a smaller
> criteria? thank you sir.
> 
> Rajak
> 
> 
> 
> _______________________________________________
> DFTB-Plus-User mailing list
> DFTB-Plus-User at dftb-plus.info
> http://www.dftb-plus.info/mailman/listinfo/dftb-plus-user
> 

-- 
      Dr. B. Hourahine, SUPA, Department of Physics,
    University of Strathclyde, John Anderson Building,
            107 Rottenrow, Glasgow G4 0NG, UK.
    +44 141 548 2325, benjamin.hourahine at strath.ac.uk

2013/4 THE Awards Entrepreneurial University of the Year
      2012/13 THE Awards UK University of the Year

   The University of Strathclyde is a charitable body,
        registered in Scotland, number SC015263


More information about the DFTB-Plus-User mailing list