[CPMD-list] Energy conservation etc.

[padma at uiuc.edu]

Dear Axel,

Thanks for the suggestions.    

---- Original message ----
>Date: Tue, 1 Nov 2005 14:21:57 -0500 (EST)
>From: Axel Kohlmeyer <akohlmey at vitae.cmm.upenn.edu>  
>Subject: Re: [CPMD-list] Energy conservation etc.  
>To: padma at uiuc.edu
>Cc: cpmd-list at cpmd.org
>
>On Tue, 1 Nov 2005 padma at uiuc.edu wrote:
>
>PK> Dear cpmd users, 
>
>dear padma,
>
>how does EKINC behave during the simulation?
>does it remain almost constant?

My EKINC and TEMPP fluctuates about the set values and 
show no noticeable drift in the 5ps run I mentioned. 

>
>i would suggest two changes due to using uspps.
>first, you should increase the density cutoff, e.g.
>by changing DUAL to 5.0 or even 6.0. unfortunately,
>that will come with a significant performance penalty.
>second, you should try to lower your timestep, e.g.
>to 3.0 and see if it makes a difference and i would use
>it in combination with EMASS 400.0. 

I will try with these modifications. If it turns out to 
be very expensive may be I should switch to MT_BLYP 
psp's and use higher cut off's (~ 70 Ryd.), right?  

thanks,
Padma

>
>with uspps you have to be much more careful than
>with norm-conserving pseudopotentials.
>
>greetings from sunny philadalphia,
>    axel.
>
>
>-- 
>=======================================================================
>Axel Kohlmeyer  e-mail: akohlmey at cmm.upenn.edu, web:
www.cmm.upenn.edu
>   Center for Molecular Modeling   --   University of
Pennsylvania
>Department of Chemistry, 231 S.34th Street, Philadelphia, PA
19104-6323
>tel: 1-215-898-1582,  fax: 1-215-573-6233,  office-tel:
1-215-898-5425
>=======================================================================
>If you make something idiot-proof, the universe creates a
better idiot.
>
>