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 > >
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