[QE-users] vc-relax for getting polymer bond lengths gives error in overlap matrix

[Paolo Giannozzi]

On Tue, Aug 6, 2019 at 8:36 PM MARIA CATERINA CEVALLOS BRENES <
MARIA.CEVALLOS at ucr.ac.cr> wrote:


> However, I'm still not getting the dimerization expected.
>

it's a known problem of DFT in simple GGA form: (almost) no dimerization in
polyacetylene. The funny thing is that if you do the calculation with an
unconverged k-point grid, you get a decent dimerization, that disappears if
you push the convergence of k-points

Paolo
-- 
Paolo Giannozzi, Dip. Scienze Matematiche Informatiche e Fisiche,
Univ. Udine, via delle Scienze 208, 33100 Udine, Italy
Phone +39-0432-558216, fax +39-0432-558222
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