The correct DFT label for rVV10 is "rVV10", not "vv10". By setting "vv10", all you get is the nonlocal part, with no other XC contributions. The output is misleading: Exchange-correlation = VV10 ( 0 0 0 0 3) but the four 0's mean respectively "no exchange", "no correlation", "no gradient correction to exchange", "no grad. corr. to correlation". In the svn version there is a further check to prevent this kind of misunderstanding, but it was added only recently.
Paolo On Thu, 2014-10-16 at 12:03 +0100, Andrea Floris wrote: > Dear quantum-ESPRESSO users, > > > I am running some calculations with espresso 5.1 and the van der > Waals > rVV10 functional. > > > First, with the program: > > > generate_rVV10_kernel_table.x > > > > > I generated the universal file: > > > rVV10_kernel_table > > > > > > > > Then I tried three systems up to now, > > 1. two water molecules (insulating) > 2. a surface with some organic molecules on top (insulating). This is > the system I am actually interested in. > 3. graphite, with some smearing > > > In the first two cases > the energy seems to reach convergence but then > suddenly the scf accuracy increases , like this > > > estimated scf accuracy < 0.06260677 Ry > estimated scf accuracy < 0.04294545 Ry > estimated scf accuracy < 0.02031181 Ry > estimated scf accuracy < 0.01888999 Ry > estimated scf accuracy < 0.01019674 Ry > estimated scf accuracy < 0.00222739 Ry > estimated scf accuracy < 0.00317661 Ry > estimated scf accuracy < 0.00370097 Ry > estimated scf accuracy < 0.00396386 Ry > estimated scf accuracy < 0.00018021 Ry > estimated scf accuracy < 1.54950129 Ry > estimated scf accuracy < 1.54973018 Ry > estimated scf accuracy < 1.54679045 Ry > > > > ...and so on and does not converge after 100 steps. I tried to reduce > the mixing to 0.1, or even smaller, without any effect. (see > attachments) > > > For the more complex surface+molecules system, the behaviour is > similar. > > > For the graphite with some smearing, the eigenvectors of the > Hamiltonian fail to converge in the diagonalization process. (see > attachment) > > > I would appreciate some help to ascertain if: > > > > 1. I am doing something wrong somewhere? > 2. there is an issue in the convergence of rVV10 with insulators? > 3. is there a (different) issue with rVV10 and smearing? > > > I am aware that water calculations with rVV10 have been successfully > performed, so I would appreciate very much your suggestions. > > > Thanks > > > Best, > Andrea > > > -- > Dr Andrea Floris > Research Associate > King's College London > Strand, London WC2R 2LS > United Kingdom > Phone: +44 (0) 207 848 2064 > Fax : +44 (0) 207 848 2420 > Location: Strand Building, 4th floor, Room 4.02 > Emails: andrea.flo...@kcl.ac.uk, an.flo...@gmail.com > > _______________________________________________ > Pw_forum mailing list > Pw_forum@pwscf.org > http://pwscf.org/mailman/listinfo/pw_forum > > -- Paolo Giannozzi, Dept. Chemistry&Physics&Environment, Univ. Udine, via delle Scienze 208, 33100 Udine, Italy Phone +39-0432-558216, fax +39-0432-558222 _______________________________________________ Pw_forum mailing list Pw_forum@pwscf.org http://pwscf.org/mailman/listinfo/pw_forum