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real space hopping integral Date: 2015/04/05 17:15 Name: Riemann   <riemann.derakhshan@gmail.com> Dear openmx Users and developers When I've run the symGra.dat input file from wf_example. When I want to extract the real space hopping integrals from symGra.HWR files, I've faced wit this set of hopping integrals that I've attached below. I'm little confused about it. From the papers I know that real space hopping integral between Carbon atoms in graphene is about 1.6 (eV) . But all of this hopping parameters are very less than it. You do favor if you give me any guidance about it. Sincerely Yours Riemann Real-space Hamiltonian in Wannier Gauge on Wigner-Seitz supercell. Number of Wannier Function 8 Number of Wigner-Seitz supercell 73 Lattice vector (in Bohr) 3.99887 -2.30875 0.00000 0.00000 4.61749 0.00000 0.00000 0.00000 37.79452 collinear calculation spinsize 1 Fermi level -0.155255 . . . R ( 0 0 0 ) 1 1 1 -0.090831456926 -0.000000000000 1 2 -0.118878494834 0.000000000000 1 3 -0.118878516842 0.000000000000 1 4 0.000000000022 0.000000000000 1 5 0.116974747585 -0.000000000000 1 6 -0.004314166219 -0.000000000000 1 7 -0.004314174132 0.000000000000 1 8 0.000000000019 0.000000000000 2 1 -0.118878494834 -0.000000000000 2 2 -0.090989070649 0.000000000000 2 3 -0.118960152320 -0.000000000000 2 4 -0.000000000004 0.000000000000 2 5 -0.307814337657 0.000000000000 2 6 -0.093010524796 -0.000000000000 2 7 0.051001898245 -0.000000000000 2 8 -0.000000000019 0.000000000000 3 1 -0.118878516842 -0.000000000000 3 2 -0.118960152320 0.000000000000 3 3 -0.090989103984 0.000000000000 3 4 -0.000000000003 -0.000000000000 3 5 -0.307814334194 -0.000000000000 3 6 0.051001862013 0.000000000000 3 7 -0.093010471766 0.000000000000 3 8 -0.000000000019 0.000000000000 4 1 0.000000000022 -0.000000000000 4 2 -0.000000000004 -0.000000000000 4 3 -0.000000000003 0.000000000000 4 4 -0.137416203899 0.000000000000 4 5 0.000000000072 -0.000000000000 4 6 0.000000000011 -0.000000000000 4 7 0.000000000010 -0.000000000000 4 8 -0.112563484812 0.000000000000 5 1 0.116974747585 0.000000000000 5 2 -0.307814337657 -0.000000000000 5 3 -0.307814334194 0.000000000000 5 4 0.000000000072 0.000000000000 5 5 -0.069476592396 -0.000000000000 5 6 -0.120318181858 -0.000000000000 5 7 -0.120318163082 -0.000000000000 5 8 -0.000000000002 0.000000000000 6 1 -0.004314166219 0.000000000000 6 2 -0.093010524796 0.000000000000 6 3 0.051001862013 -0.000000000000 6 4 0.000000000011 0.000000000000 6 5 -0.120318181858 0.000000000000 6 6 -0.069284723171 0.000000000000 6 7 -0.120227682262 0.000000000000 6 8 -0.000000000008 0.000000000000 7 1 -0.004314174132 -0.000000000000 7 2 0.051001898245 0.000000000000 7 3 -0.093010471766 -0.000000000000 7 4 0.000000000010 0.000000000000 7 5 -0.120318163082 0.000000000000 7 6 -0.120227682262 -0.000000000000 7 7 -0.069284663398 0.000000000000 7 8 -0.000000000007 -0.000000000000 8 1 0.000000000019 -0.000000000000 8 2 -0.000000000019 -0.000000000000 8 3 -0.000000000019 -0.000000000000 8 4 -0.112563484812 -0.000000000000 8 5 -0.000000000002 -0.000000000000 8 6 -0.000000000008 -0.000000000000 8 7 -0.000000000007 0.000000000000 8 8 -0.137416203896 -0.000000000000 . . .

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Re: real space hopping integral ( No.1 ) Date: 2015/04/06 20:20 Name: T. Ozaki Hi, I assumed that your input file is based on 'symGra.dat' in work/wf_example. In the input file, the initial projectors for WFs are given by <Wannier.Initial.Projectors C1-sp2 0.333333333 -0.333333333 0.00000000000000 0.0 0.0 1.0 -1.0 0.0 0.0 C1-pz 0.333333333 -0.333333333 0.00000000000000 0.0 0.0 1.0 -1.0 0.0 0.0 C1-sp2 -0.333333333 0.333333333 0.00 0.0 0.0 1.0 1.0 0.0 0.0 C1-pz -0.333333333 0.333333333 0.00 0.0 0.0 1.0 1.0 0.0 0.0 Wannier.Initial.Projectors> Thus, the index of '4' and '8' correspond to pz orbitals. If you look at the line for 'R ( 0 0 0 ) 1': 4 8 -0.112563484812 0.000000000000 you get -0.112563484812*27.2 -> about -3.06 eV So, the nearest neighbor hopping integral between pz and pz orbitals, corresponding to pi-pi interation, is about -3.06 eV, which is close to the value (-2.99 eV) reported in PRB 87, 195450 (2013). Regards, TO

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