Find Nodes calculation

[linton1995]

I, Amar beginner to using wannier_tools to calculates the Weyl points in the system(AB2C2) which contain f-block elements(A). where I use wien2k for DFT, then wannier90 to construct the wannier90_hr.dat file. I attached my [[[ wt.in ]]] file here. But when I do the calculation I got 700 nodes in the Nodes.dat file but the compound is Weyl semimetal having single pair of Weyl points between Gamma & A direction. &TB_FILE Hrfile = "wannier90_hr.dat" Package = 'Wien2k' ! obtained from VASP, it could be 'VASP', 'QE', 'Wien2k', 'OpenMx' /

LATTICE Angstrom 3.853728 -2.224951 0.000000 0.000000 4.449902 0.000000 0.000000 0.000000 14.700006

ATOM_POSITIONS 10 ! number of atoms in unit cell Cartisen ! Direct or Cartisen coordinate A 0.00000 0.00000 0.00000 B 1.48330 2.96660 4.65373 B 2.96660 1.48330 10.04628 B 2.96660 1.48330 2.69627 B 1.48330 2.96660 12.00373 C 1.48330 2.96660 1.81302 C 2.96660 1.48330 12.88698 C 2.96660 1.48330 5.53698 C 1.48330 2.96660 9.16303 A 1.48330 2.96660 9.16303 PROJECTORS 7 1 1 1 3 4 3 3 3 1 ! number of projectors for each atom A s s s s s s s B s B s B s B px py pz C s px py pz C px py pz C px py pz C px py pz A s !> &CONTROL BulkBand_calc = F BulkGap_plane_calc = F BulkFS_plane_calc = F SlabBand_calc = F SlabSS_calc = F SlabArc_calc = F SlabSpintexture_calc = F BerryCurvature_calc = F WeylChirality_calc = F FindNodes_calc = T /

&SYSTEM NSLAB = 10 NSLAB1= 4
NSLAB2= 4
NumOccupied = 37 ! NumOccupied SOC = 1 ! if the SOC effect is included in you TB model. E_FERMI =0 ! e-fermi surf_onsite= 0.0 ! surf_onsite /

&PARAMETERS Eta_Arc = 0.001 ! infinite small value, like brodening E_arc = 0.0 ! energy for calculate Fermi Arc OmegaNum = 400 ! omega number
OmegaMin = -0.6 ! energy interval OmegaMax = 0.5 ! energy interval Nk1 = 15 ! number k points Nk2 = 15 ! number k points Nk3 = 15 ! number k points NP = 1 ! number of principle layers Gap_threshold = 0.000001 ! threshold for GapCube output /

SURFACE ! See doc for details 1 0 0 0 1 0 0 0 1

KPATH_BULK ! k point path 2 ! number of k line A 0.000 0.000 0.500 G 0.000 0.000 0.000 G 0.000 0.000 0.000 A 0.000 0.000 0.500 KPATH_SLAB 1 ! numker of k line for 2D case G 0.0 0.0 M 0.3 0.0

KPLANE_SLAB -0.3 -0.2 ! Original point for 2D k plane 0.6 0.0 ! The first vector to define 2D k plane 0.0 0.4 ! The second vector to define 2D k plane for arc plots

KPLANE_BULK 0.115 0.02 0.00 ! Original point for 3D k plane 0.01 0.00 0.00 ! The first vector to define 3d k space plane 0.00 0.04 0.00 ! The second vector to define 3d k space plane

KCUBE_BULK -0.50 -0.50 -0.50 ! Original point for 3D k plane 1.00 0.00 0.00 ! The first vector to define 3d k space plane 0.00 1.00 0.00 ! The second vector to define 3d k space plane 0.00 0.00 1.00 ! The third vector to define 3d k cube

WANNIER_CENTRES ! copy from wannier90.wout Cartesian 0.000076, -0.000625, 0.003085 -0.000361, 0.000504, 0.000641 0.000464, 0.000062, -0.003749 -0.001341, -0.007540, -0.001325 0.004071, 0.000324, -0.000146 -0.001134, 0.001677, -0.000436 -0.000393, -0.007032, -0.008455 1.309172, -2.242856, 4.499321 -1.231164, -2.219301, -4.434112 -1.297892, -2.225730, 2.841683 -2.568396, -0.020449, -3.108397 2.606872, -0.190314, 5.584989 1.270967, -2.305312, 1.758240 0.306639, -2.356649, 0.104981 1.356771, -2.204801, 1.678207 -1.430060, -2.268763, -1.736964 -1.264592, -2.215539, -1.774103 -0.836964, -3.937342, -0.084466 -1.213917, -2.242356, -1.704171 -1.161247, -2.401514, 3.140495 -1.341838, -2.260814, 5.613582 -1.272350, -2.127455, 5.611900 -1.282360, -2.212805, 5.738577 -2.323071, -0.914721, -6.583758 -2.540891, 0.057116, -5.609684 -2.548483, -0.050504, -5.567859 -2.574541, 0.021156, -5.667721 1.275504, -2.209166, 4.224321 -1.388438, -2.810893, -7.087532 -1.062765, -2.341418, 1.663503 -2.572231, 0.017371, -2.915521 1.204093, -2.145603, 1.608414 1.325057, -2.260293, 1.778837 1.344900, -2.221926, 1.795590 1.296084, -2.247153, 1.716519 -1.314261, -2.225291, -4.280418 -1.263231, -2.172729, -1.779470 -1.284572, -2.251268, -1.779668 -1.239022, -2.210135, -1.696414 -1.115505, -2.322060, 5.944665 -1.364517, -2.276686, 5.607821 -1.249718, -2.170746, 5.590422 -0.320431, -2.767021, 7.499557 -2.332916, 0.076526, -1.037027 -2.488087, 0.043992, -5.610897 -2.552403, -0.080825, -5.603290 -2.680406, -0.022328, -5.651873 -0.000540, -0.000980, 7.348152 0.002719, -0.001509, 7.349819 -0.000494, -0.000245, 7.348711 0.001274, -0.006672, 7.349485 -0.000745, -0.000575, 7.350059 -0.001586, -0.004016, 7.356662 0.003938, 0.000609, 7.352725

[quanshengwu]

FindNodescalc will find all the local minimal of |E{N+1}(k)-E_N{k}|. If the energy gap of all the nodes is zero, it means that's the result! You have to check whether you set the right Num_Occupied in the wt.in or your hr.dat is correct.

[GriffithRufo]

Hi, linton1995, how many of these nodes possess energy close to zero (or equal to zero)?

[bushra-lab]

Hi linton1995, are you able to solve this issue, I am facing the same issue, by increasing the 0.000001 (threshold for GapCube output) Nodes points are reduced but still they are not following the nogo theorem(+WP points are greater than -WPs). I tried to reproduce the results of one of the papers, and m still facing the same issue. To check the number of occupied bands. (Attached is the fig), I exactly know which band I am interested in. confirmed with xmgrace as well.

吴泉生 Can you please suggest to us something?.. changing GapCube is not making any diffrence.

[quanshengwu]

@bushra-lab If there are many nodes that the energy gap is close to zero, then you should check that whether there are nodal lines or nodal surfaces. You can plot all the nodes in a scatter plot mode to visualize the nodes. By the way, it's better to symmetrize the tight-binding Hamiltonian before searching the nodes, especially when searching the nodal lines or nodal surfaces since there are almost always protected by the symmetries. We provided one tool to symmetrize the hr file in https://github.com/quanshengwu/wannier_tools/tree/master/utility/wannhr_symm. It's written by Dr. Yue, you can write to him when necessary.