On Thu, Dec 23, 2021 at 3:51 PM Husak Michal <[email protected]> wrote:
We can probably decipher what is QE doing internally > no need to do that. You have in output the primitive cell and atoms in the primitive cell. You find what you call the "standard" cell, presumably the corresponding "P" one (the primitive cell is "F", "I", whatever), n times larger (n=2 or 4) than the primitive cell. Then you look for n lattice points in the primitive cell that are not lattice points of the "standard" cell. Or at least, this is my understanding of your problem Paolo ________________________________ > From: users <[email protected]> on behalf of Paolo > Giannozzi <[email protected]> > Sent: Thursday, December 23, 2021 10:25:42 AM > To: Quantum ESPRESSO users Forum > Subject: Re: [QE-users] QE automatically converge centered cell to > primitive ? > > I am not sure I understand what you mean. If you supply the structure and > atomic positions via the space group and Wyckoff positions, QE generates > the primitive (smallest) unit cell and corresponding lattice. QE does not > change the symmetry or the structure by its own will, unless there is a bug > for your specific case. If you prefer the so-called "conventional" unit > cell, you need to consider the atoms that are in the conventional unit cell > but not in the primitive one. > > Paolo > > On Wed, Dec 22, 2021 at 5:07 PM Michal Husak <[email protected] > <mailto:[email protected]>> wrote: > Hi > > We had entered inside QE a structure described by fractional > coordinates (asymmetric unit cell) > and space group (C 2/c ) .... > From the output we see QE had itself transformed the structure to > another space group and unit cell > (probably P 2/c triclinic system) to get speed of calculation .... > > Question: > - does QE anywhere mention, this transformation was done ? > - does it anywhere give the used transformation matrix ? > > We simply need to reconstruct from the QE the atom positions > corresponding to the original CIF data .... > > Michal Husak > UCT Prague > > > > _______________________________________________ > Quantum ESPRESSO is supported by MaX (www.max-centre.eu< > http://www.max-centre.eu>) > users mailing list [email protected]<mailto: > [email protected]> > https://lists.quantum-espresso.org/mailman/listinfo/users > > > -- > Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche, > Univ. Udine, via delle Scienze 206, 33100 Udine, Italy > Phone +39-0432-558216, fax +39-0432-558222 > > _______________________________________________ > Quantum ESPRESSO is supported by MaX (www.max-centre.eu) > users mailing list [email protected] > https://lists.quantum-espresso.org/mailman/listinfo/users > -- Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche, Univ. Udine, via delle Scienze 206, 33100 Udine, Italy Phone +39-0432-558216, fax +39-0432-558222
_______________________________________________ Quantum ESPRESSO is supported by MaX (www.max-centre.eu) users mailing list [email protected] https://lists.quantum-espresso.org/mailman/listinfo/users
