[Pw_forum] Choice of irreducible representations with ph.x

Dal Corso Andrea dalcorso at sissa.it
Thu Apr 2 11:56:32 CEST 2009

I rechecked the nrapp option in the cvs version of ph.x, but I cannot
find any problem.
Could you please send the input of pw.x, just to see if I can reproduce
your problem.


On Tue, 2009-03-31 at 14:57 +0200, Cristian Degli Esposti Boschi wrote:
> I would like to perform a phonon calculation
> at Gamma making a choice of only a selected number
> of irreducible representations. After a proper scf
> calculation I use with ph.x with an input file
> like the following one:
> Phononic spectrum (1) of CoM (at Gamma)
>   &inputph
>   amass(1)=1.00794,
>   amass(2)=12.011,
>   amass(3)=14.007,
>   amass(4)=15.999,
>   amass(5)=55.845,
>   prefix='CoM',
>   outdir='/scratch/userinfm/cne0fm4a/CoM/results/',
>   iverbosity=1,
>   epsil=.false.,
>   fildyn='CoM.dm',
>   nrapp=1,
>   /
>   0.0 0.0 0.0
>   1
> The problem is that the calculation seems to proceed ignoring
> the nrapp value and the list of numbers I put in the last line
> and all the irreps are considered. This happens both for nrapp=1
> (one value in the list) or nrapp>1 (nrapp values in the list).
> pw.x and ph.x are run on the CINECA cluster where there appears to be QE 
> ver. 4.1CVS and I would liketo save cpu time by excluding the undesired 
> irreps.
> Using the same syntax (nrapp and the list of irreps at the end)
> to modify the scripts of example02 I successfully select only one of the 
> two irreps for Si with QE ver. 3.2 installed on a desktop pc (reporting 
> the message "Not done in this run"). Might it be a version issue?
> Thanks a lot for your help and time.
Andrea Dal Corso                    Tel. 0039-040-3787428
SISSA, Via Beirut 2/4               Fax. 0039-040-3787528
34014 Trieste (Italy)               e-mail: dalcorso at sissa.it

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