Re: [Phonopy-users] [**SPAM?**] Re: phonopy-users

[Shilendra K. S. <sh...@ii...>]

Dear Prof. Aldo Humberto Romero,

Thank you for your reply and suggestions. FORCE_CONSTANTS = READ has
resolved my error.

Shilendra


> It is FORCE_CONSTANTS = READ
> No FORCE CONSTANTS!! See the underscore
>
> With respect to your questions
>
>
> 1. How much bigger supercell we should take in account ?
> Depends… convergence with respect to supercell size is desired.. the
> larger the better… finally, the supercell will define the number of Q
> points you have calculated exactly, the others will be interpolated… for
> the 2x2x1, you have basically 5 points (including Gamma)… and in many
> systems this is not enough.. this is really system dependent
>
>
> 2. How much big KPOINTS mesh we should taken and What type ?
>
> That is a question on Electronic structure and no on Thermal properties..
> depends if your system is a semiconductor or a metal.. you always have to
> converge with respect to Kpoints and Ecut before anything else
>
>     3. In manual it iswritten we shoul take for VASP users LREAL= FALSE
> but
>     when I was doing calculation with LREAL=FALSE my programme was
> terminating
>     automaticaaly or stopping middle of the calculation. So my query is
> that
>     we can take LREAL= Auto.
>
> No.
>
>
>
> ________________________________________
>
> Prof. Aldo Humberto Romero
> American Physical Society Fellow
> Physics and Astronomy Department
> West Virginia University
> Phone: (304) 2936317
> email: alr...@ma...
>
>
> On 1/4/17, 5:51 AM, "Shilendra Kumar Sharma" <sh...@ii...> wrote:
>
>     Dear PHONOPY users,
>
>     My system has 24 atoms(tetragonal) unit cell. I want to calculate
>     thermodynamic properties specially zero point energy. I am VASP user
> and
>     using DFPT (IBRION=8) method for calculating force constants.
>
>     I made 2*2*1 supercell from phonopy and rename SPOSCAR to POSCAR and
>     calculated force constant my INCAR is
>
>     SYSTEM = LVO(2 2 1)
>     ISTART = 0
>     ICHARG = 2
>     PREC = Accurate
>     ENCUT = 520.000
>     IBRION = 8
>     EDIFF = 1.0e-08
>     IALGO = 38
>     ADDGRID = .True.
>     ISMEAR = 0
>     SIGMA = 0.1
>     LREAL = Auto
>     LWAVE = False
>     LCHARG = False
>
>     After VASP job finishing, I calculated force constant by command
>
>     phonopy --fc vasprun.xml
>
>     It created FORCE_CONSTANTS files.
>
>     Now I am calculating thermal properties by command
>
>     phonopy -t mesh.conf
>
>     then it is showing message
>            _
>       _ __ | |__   ___  _ __   ___   _ __  _   _
>      | '_ \| '_ \ / _ \| '_ \ / _ \ | '_ \| | | |
>      | |_) | | | | (_) | | | | (_) || |_) | |_| |
>      | .__/|_| |_|\___/|_| |_|\___(_) .__/ \__, |
>      |_|                            |_|    |___/
>                                           1.11.6
>
>
>     FORCE_SETS not found.
>       ___ _ __ _ __ ___  _ __
>      / _ \ '__| '__/ _ \| '__|
>     |  __/ |  | | | (_) | |
>      \___|_|  |_|  \___/|_|
>
>
>     Where I am doing mistake ? My mesh.conf file is
>
>     DIM= 2 2 1
>     MP= 6 6 6
>     FORCE CONSTANT= Read
>
>     My queries are fillowing:
>
>     1. How much bigger supercell we should take in account ?
>     2. How much big KPOINTS mesh we should taken and What type ?
>     3. In manual it iswritten we shoul take for VASP users LREAL= FALSE
> but
>     when I was doing calculation with LREAL=FALSE my programme was
> terminating
>     automaticaaly or stopping middle of the calculation. So my query is
> that
>     we can take LREAL= Auto.
>
>     Any other advice on termination of programme.
>
>     Thank You All PHONOPY user
>
>     Shilendra
>
>
>
>
>
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