[Pw_forum] hubbard potential

[Mojtaba Rahimi]

Dear all

I'm using QE to calculate U-hubbard for graphene. I've used 18 atom super
cell which has hexagonal structure, and linear response approach code,
which is written by Dr. cococcioni. I've modified cococcioni's shell
scripts which has been located at training part of QE website for graphene,
but I've confronted to some problem and I have some question about this cod
as well. I hope someone could answer me.

Thanks in advance

I prefer to propose my question at first:

   -

   As you know in graphene pz orbital which is perpendicular to graphene
   plane, and play the most important role in transport and optical
   properties, isn't localized, but that cod is written for localized orbital
   such as d, and f(at least from my knowledge). can I use this cod for
   graphene?
   -

   At atomic position file, the three first line specifies the parameter
   cell. Is it important that parameter cell to be cubic or it doesn't matter
   what it is?
   -

   In this approach we can just determine the on-site hubbard potential. f
   I tended to determine the nearest neighbor and next nearest neighbor
   hubbard potential, how would I do them by this code?

   And my problems are:
   -

   when I calculated the U for super cell dimension n=1-2, I obtained a
   negative U, which i think is wrong because U have to be positive.
   -

   When I changed the super cell dimension to n=3,... I encountered to a
   problem which I mentioned below. How can I over com to this problem. I
   would be grateful if somebody could help me.

*** glibc detected *** ./r.x: free(): invalid next size (normal):
0x09d29018 ***

======= Backtrace: =========

[0x82507db]

[0x825368b]

[0x81f4324]

[0x81f4299]

[0x805181d]

[0x804824a]

[0x823805d]

[0x8048131]

======= Memory map: ========

08048000-082c3000 r-xp 00000000 08:11 77561870
/home/nano2/mojtaba-work/plan/isolated-graphen/U-graphene/Ucalc/r.x

082c3000-082ce000 rwxp 0027b000 08:11 77561870
/home/nano2/mojtaba-work/plan/isolated-graphen/U-graphene/Ucalc/r.x

082ce000-088de000 rwxp 082ce000 00:00 0

09d23000-09d45000 rwxp 09d23000 00:00 0

55555000-556d2000 rwxp 55555000 00:00 0

55700000-55721000 rwxp 55700000 00:00 0

55721000-55800000 ---p 55721000 00:00 0

ffc05000-ffc2a000 rwxp 7ffffffd9000 00:00 0 [stack]

ffffe000-fffff000 r-xp ffffe000 00:00 0

forrtl: error (76): IOT trap signal


-- 
-----
Mojtaba Rahimi (Mr.)
Master of science -condensed matter,

Email: mrahimi93 at gmail.com

Phone:+ 98-9134515197
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