Thanks to both of you for the response! On Mon, Jul 20, 2020, 03:59 Timrov Iurii <[email protected]> wrote:
> Dear Andrew, > > > > From looking into the code a bit it appears to me that it generates a > 3x3x3 supercell with (I am guessing) ±R in each direction of the lattice > vectors. > > > Right > > > > I see that for the orginal unit cell the indices go 1-nat > > > Right > > > > ...but I am unsure on how the indices in the adjacent unit cells are > chosen. > > > See the routine q-e/PW/src/intersite_V.f90, lines 88-113. > > > When sc_size=1 you have a supercell 3x3x3, when sc_size=2 you have 5x5x5, > etc. In most cases 3x3x3 is enough. > > > > I would like to specify a hubbard V between atom1 at the edge of the > unit cell R=[0,0,0] and a nearest neighbor, atom2, in an adjacent unit cell > R=[0,0,1]. > > > It can be quite painful to do all this "by hand". I suggest to use the HP > code, and you will get all possible pairs of neighbors automatically, and > then you choose what you want. We will try to prepare some tutorial about > DFT+U+V in the near future. > > > Greetings, > > Iurii > > > -- > Dr. Iurii Timrov > Postdoctoral Researcher > STI - IMX - THEOS and NCCR - MARVEL > Swiss Federal Institute of Technology Lausanne (EPFL) > CH-1015 Lausanne, Switzerland > +41 21 69 34 881 > http://people.epfl.ch/265334 > ------------------------------ > *From:* users <[email protected]> on behalf of > Andrew Supka <[email protected]> > *Sent:* Sunday, July 19, 2020 1:27:09 AM > *To:* Quantum ESPRESSO users Forum > *Subject:* Re: [QE-users] lda_plus_u_kind=2 > > Thank you for the response. From looking into the code a bit it appears to > me that it generates a 3x3x3 supercell with (I am guessing) ±R in each > direction of the lattice vectors. I see that for the orginal unit cell the > indices go 1-nat but I am unsure on how the indices in the adjacent unit > cells are chosen. > > Is there a part of that code that you'd suggest I check for information on > that? > > Andrew Supka > Postdoc Physics > Central Michigan University > > > On Sat, Jul 18, 2020, 16:54 Matteo Cococcioni <[email protected]> > wrote: > >> This part of the code is still not so user-friendly (in fact still under >> improvement). >> yes the code recognizes all the neighbors at the same distance and puts >> the same V between them. You just need to find one of them in the unit cell >> and make sure that that atom (or one of its periodic replicas) belongs to >> the proper star of neighbors you are treating with V. >> In order to do that it might be a good idea to shift the reference atom >> to the center of the cell, so you increase the chances to find one of its >> neighbors in the unit cell. >> >> HTH >> >> Matteo >> >> Il giorno sab 18 lug 2020 alle ore 17:38 Andrew Supka <[email protected]> >> ha scritto: >> >>> I have been experimenting with the developers version cloned from >>> gitlab. I would like to specify a hubbard V between atom1 at the edge of >>> the unit cell R=[0,0,0] and a nearest neighbor, atom2, in an adjacent unit >>> cell R=[0,0,1]. It appears that the code automatically finds the equivalent >>> atoms to the site you put a hubbard U and applies the V to those also. >>> >>> I have attempted to put the V on the equivalent to atom2 in R=[0,0,0] >>> but it assumes I want the V between the two atoms in R=[0,0,0]. >>> >>> I have also tried adding the V using an index corresponding to another >>> unit cell. I'm not sure how the indices for the atoms are chosen when the >>> algorithm finds equivalent sites. >>> >>> Is there a simple way to do what I detailed above? Also if I'm way off >>> please let me know. >>> >>> Thank you for any information you can provide. >>> >>> Andrew Supka >>> Postdoc Physics >>> Central Michigan University >>> _______________________________________________ >>> 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 >> >> >> >> -- >> Matteo Cococcioni >> Department of Physics >> University of Pavia >> Via Bassi 6, I-27100 Pavia, Italy >> tel +39-0382-987485 >> e-mail [email protected] <[email protected]> >> _______________________________________________ >> 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
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