Dear all
I perform the relax calculate to the crystal structure. After 11 step bfgs,
the total force and total scf correction had reach to the criterion,
however, the total stress was so big P=-3443.87. I have no idea about deal
with the case, could anyone give some advices? Thanks in advance.
t
Dear Wang,
The 'relax' process optimizes the structure within
given geometric constraint. It does'nt care for stress. It minimizes force
only in the given constraint. If you want to minimize the stress also you
have to do 'vc-relax' calculation, It will give you what you want.
Dear Mohnish:
I have used the 'vc-relax' process optimized the cell parameter, however,
the result were seem to deviate from the initial value (experimental value)
too much.The aim of the structure optimizes is for calculating the Raman
spectra of the structure, I think the bad structure ( not coin
Wang Di wrote:
> ecutwfc = 30 ,
> ATOMIC_SPECIES
>Li6.94100 03-Li.LDA.fhi.UPF
>Al 26.98154 13-Al.LDA.fhi.UPF
>Ca 40.07800 20-Ca.LDA.fhi.UPF
> F 18.99840 09-F.LDA.fhi.UPF
30 Ry is too low for norm-c
Dear Wang,
Are you sure that this is your input file? Because the
calculation flag says it is "scf" ..Which will not definitely do the relax
calculation
On Mon, Sep 20, 2010 at 3:32 PM, Wang Di wrote:
> Dear Mohnish:
> I have used the 'vc-relax' process optimized the cell
Dear Wang:
All these parameters in the blow article may influence the relaxed
structure.
*?Designing meaningful density functional theory calculations in materials
science?a prime.?*
*
*
***
*
On Mon, Sep 20, 2010 at 6:02 PM, Wang Di wrote:
> Dear Mohnish:
> I have used the 'vc-relax' process opt
I am very sorry that the input file was wrong, the relax input file is the
similar to the file.
&CONTROL
calculation = 'relax' ,
restart_mode = 'from_scratch' ,
wf_collect = .true. ,
outdir = '/lustre/AIOFM/gxgu/workLCAF/6/te
*Thanks for your advices!
*
> -
>> *Wang Di**
>> The Crystal Lab,*
>> *AnHui Institute of Optics and Fine Mechanics, ***
>> *Chinese Academy of Sciences,**
>> No350. , Shushanhu Road, Hefei, 230031, China**,
>> E-mail: didi5158 @g
0
> From: Wang Di
> Subject: [Pw_forum] question about the stress in relax process
> To: PWSCF Forum
> Message-ID:
>
> Content-Type: text/plain; charset="iso-8859-1"
>
> Dear all
>
> I perform the relax calculate to the crystal structure. After 11
