Xiaolin,
sorry, I have not tried Raman calculation yet.
Jiqiang
在 2015-10-30 00:26:09，"Xiaolin Xu" <[email protected]> 写道：
>Hi Jiqiang,
>
>
>Thank you very much for your help!
>
>
>I tried using only gamma point, but I got an error message when I calculated
>phonon saying "can't start from gamma tricks...". Besides, I need to calculate
>the raman frequencies after phonon calculation, so I think it's better if I
>use more k points.
>
>
>Have you tried Raman calculation? Could you give me more advice?
>
>
>Best,
>
>
>Xiaolin
>
>
>On Wed, Oct 28, 2015 at 10:21 PM, Xiaolin Xu <[email protected]> wrote:
>
>Hi Jiqiang,
>
>
>Thank you very much for your help!
>
>
>I tried using only gamma point, but I got an error message when I calculated
>phonon saying "can't start from gamma tricks...". Besides, I need to calculate
>the raman frequencies after phonon calculation, so I think it's better if I
>use more k points.
>
>
>Have you tried Raman calculation? Could you give me more advice?
>
>
>Best,
>
>
>Xiaolin
>
>
>On Wed, Oct 28, 2015 at 6:20 PM, jqli14 <[email protected]> wrote:
>(1)employ k_points gamma instead of k_pionts automatic 1 1 1 0 0 0, although
>both give the same result, but the later does not call the gamma point
>specific algorithm to speed the calculation.
>(2)if it can not converge within handreds of electronic steps, reduce the
>value of mixing_beta or change the mixing_mode.
>
>Jiqiang Li
>
>
>
>在 2015-10-29 07:57:58，"Xiaolin Xu" <[email protected]> 写道：
>
>>Dear all,
>>
>>
>>I was doing phonon dispersion calculations for lithium iron phosphate.
>>However, the calculation speed is really slow and it does not converge. Is
>>this because my system is too big? There are 28 atoms in the unit cell. My
>>input file is like this:
>>(1)
>>
>>
>>
>>&CONTROL
>>
>>calculation = "scf",
>>
>>pseudo_dir = "/home/xiaolin/pseudo",
>>
>>outdir = "/home/xiaolin/test2",
>>
>>tstress=.true.,
>>
>>tprnfor=.true.,
>>
>>nstep=100,
>>
>>/
>>
>>&SYSTEM
>>
>>ibrav = 8,
>>
>>celldm(1) = 19.749526
>>
>>celldm(2) = 0.582432,
>>
>>celldm(3) = 0.454693,
>>
>>nat = 28,
>>
>>ntyp = 4,
>>
>>ecutwfc = 80.D0,
>>
>>/
>>
>>&ELECTRONS
>>
>>mixing_beta = 0.7,
>>
>>/
>>
>>&IONS
>>
>>/
>>
>>ATOMIC_SPECIES
>>
>>Li 6.941 Li.pbe-s-hgh.UPF
>>
>>Fe 55.845 Fe.pbe-sp-hgh.UPF
>>
>>P 30.97376 P.pbe-hgh.UPF
>>
>>O 15.9994 O.pbe-hgh.UPF
>>
>>ATOMIC_POSITIONS (alat)
>>
>>Li 0 0 0
>>
>>...
>>
>>K_POINTS (automatic)
>>
>>1 1 1 0 0 0
>>
>>
>>
>>
>>(2)
>>
>>
>>
>>
>>Normal modes for lifepo4
>>
>>&inputph
>>
>>tr2_ph=1.5d-5,
>>
>>amass(1)=6.941,
>>
>>amass(2)=55.845,
>>
>>amass(3)=30.97376,
>>
>>amass(4)=15.9994,
>>
>>outdir = '/home/xiaolin/test2',
>>
>>trans=.true.,
>>
>>asr=.true.,
>>
>>nogg=.true.,
>>
>>fildyn='dmat.lifepo4'
>>
>>/
>>
>>0.0 0.0 0.0
>>
>>
>>
>>
>>
>>
>>
>>Thank you in advance!
>>
>>
>>
>>
>>Lin
>
>
>
>
>
>
>
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