[Pw_forum] matdyn.x warning message

[Mikiyas Tsegaye]

Dear Giannozzi,

As you can see in the reply I sent to Eyvaz (see below), I specified  
ASR = 'simple' in my matdyn input file. I also specify the same thing  
in my q2r.x input file. But for some reason, this is not happening. I  
tried a separate single point calculation just for gamma, and then ran  
dynmat.x with ASR = simple, and the acoustic frequencies did go to 0.  
So, does this mean that matdyn.x is not enforcing the sum rule  
appropriately?

As I have said, the same type of code has worked beautifully with Si,  
Ge, and diamond so far. I don't know what the hiccup is with my  
graphene runs.

thank  you

> On Aug 20, 2009, at 21:03 , Mikiyas Tsegaye wrote:
>
>> For examples, the acoustic modes don't go to zero at the  gamma point
>
> you need to enforce acoustic sum rule
>
>> and the acoustic and optical branches don't touch at the  K-point
>
> they do. Some time ago I heard a similar claim. I verified that they
> touch at K.
>
> P.
> ---
> Paolo Giannozzi, Dept of Physics, University of Udine
> via delle Scienze 208, 33100 Udine, Italy
> Phone +39-0432-558216, fax +39-0432-558222
>
>
> Dear Eyvaz,
>
> My q-path is the following: (from matdyn.in input file)
> -----------------------------------
> &input
> asr='simple',
> amass(1)= 12.01,
> flfrc='graphene.fc',
> flfrq='graphene.freq',
> /
> 14
> 0.0 0.0 0.0   0.0
> 0.0 0.1 0.0   0.0
> 0.0 0.2 0.0   0.0
> 0.0 0.3 0.0   0.0
> 0.0 0.4 0.0   0.0
> 0.0 0.5 0.0   0.0
> 0.1 0.1 0.0   0.0
> 0.2 0.2 0.0   0.0
> 0.3 0.3 0.0   0.0
> 0.33 0.33 0.0 0.0
> 0.3 0.3 0.0   0.0
> 0.2 0.2 0.0   0.0
> 0.1 0.1 0.0   0.0
> 0.0 0.0 0.0   0.0
>
> ------------------------------------