Thank you sir On Tue, 21 Jan 2020, 11:52 am Premkumar Thirumalaisamy, <[email protected]> wrote:
> Hi, > Always compare the energy per formula unit, if you do that in your > case there is a small different in energy which may be due to different > k-grid and energy cutoff. > I think it is better to optimize the kpoints and energy cutoff for > particular unit cell or supercell. > > On Sun, Jan 19, 2020 at 2:55 AM Manu Hegde <[email protected]> wrote: > >> Hi Pooja, >> I think CaO is a cubic crystal. You can use VESTA to >> generate a supercell. It can take .cif file. Play with it. I >> believe extending lattice parameter 2X2X2 generate a 36 atom supercell. >> HTH >> Manu >> (McMaster University) >> >> On Sat, Jan 18, 2020 at 12:38 AM Pooja Vyas <[email protected]> >> wrote: >> >>> Respected sir/madam, >>> Referring a paper on calculation of energy with vacancy in CaO, I want >>> to re-calculate the energy with the same number of atoms used in the paper. >>> They have 36 atoms in their supercell, 3 x 3 x 2 monk horst pack grid. >>> From this information, is it possible to know what could be the value of n, >>> in n x n x n supercell and what could be the initial number of atomic >>> positions defined? >>> >>> On Thu, Jan 16, 2020 at 11:58 AM Laurent Pizzagalli < >>> [email protected]> wrote: >>> >>>> Well, maybe because in your first calculation you had two atoms, and 64 >>>> in the second one.....You should try to see if multiplying -107.10 by 64/2 >>>> improve the comparison.... >>>> >>>> L. >>>> >>>> On 16/01/2020 06:23, Pooja Vyas wrote: >>>> >>>> Initially I had run my input script with ecut=100Ry and k-points= 11 11 >>>> 11 1 1 1. At that time my energy was -107.10Ry. During this run, I had >>>> specified only two atomic positions (Ca: 0 0 0, O: 0.5 0.5 0.5) >>>> For the same system but with ecut=60Ry and k-points= 3 3 3 1 1 1 the >>>> calculated energy was -3427.40Ry. During this run, I had specified 64 >>>> atomic positions. >>>> Why does total energy value vary so much? >>>> >>>> _______________________________________________ >>>> Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso) >>>> users mailing list >>>> [email protected]https://lists.quantum-espresso.org/mailman/listinfo/users >>>> >>>> >>>> -- >>>> ,,, __, >>>> /'^'\ |__| >>>> ( o o ) | >>>> --------------------------------------------------oOOO--(_)--OO|o------<[email protected]> >>>> <[email protected]>http://laurent.pizzagalli.free.fr/ >>>> Tel +33 549 49 74 99 >>>> ------------------------------------------ Fax +33 549 49 66 92 >>>> Institut P' >>>> Departement de Physique et de Mécanique des Matériaux >>>> CNRS UPR 3346 >>>> Université de Poitiers >>>> SP2MI >>>> TSA 41123 .oooO >>>> 86073 Poitiers Cedex 9, FRANCE ( ) Oooo. >>>> ----------------------------------------------------\ (----( )------- >>>> \_) ) / >>>> (_/ >>>> >>>> >>>> _______________________________________________ >>>> Quantum ESPRESSO is supported by MaX ( >>>> www.max-centre.eu/quantum-espresso) >>>> users mailing list [email protected] >>>> https://lists.quantum-espresso.org/mailman/listinfo/users >>> >>> _______________________________________________ >> Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso) >> users mailing list [email protected] >> https://lists.quantum-espresso.org/mailman/listinfo/users > > > > -- > Regards, > Premkumar Thirumalaisamy, > Research Scholar, Department of Medical Physics, > Anna University, Chennai, India - 600025. > > ------------------------------------------------------------------------------------ > "தொட்டனைத் தூறும் மணற்கேணி மாந்தர்க்குக் > கற்றனைத் தூறும் அறிவு" > ========================================== > > > _______________________________________________ > Quantum ESPRESSO is supported by MaX (www.max-centre.eu/quantum-espresso) > users mailing list [email protected] > https://lists.quantum-espresso.org/mailman/listinfo/users
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