NOTE.ToDo.txt

*  Spin Berry curvature. See Ref. [Yao & Fang, PRL 95, 156601 (2005)]

*. Z2 invariant calculation via Fukui's method or Wilson loop calculation

*. Zak phase calculation

*. Surface green function : get_surface_green

*.Calculate & construct hamiltonian via given Rij and tij : 'read_hopping_dat' and 'set_ham'

*. Print_param routine need to be improved for the case of 'LMDIF' when
writing '_temp' file. It will be much nice to see if the values are printed in
horizontal way, not by vertical manner.

*. if xx type of orbital is asigned, the onsite energy evaluation should be
checked... it seems there is some memory dump sometimes if lmdif iteration is
increased.

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# list what is done already.
*. Density of states (DOS) : get_dos routine? Done!! 2018-Jan-26
*. scaling factor  : done. 2018-Jan-15
*. constraint parameters: fix parameters not to be relaxed... Done. 2018-Jan-16
*. spin polarized case : Done. 2018-Feb-01
*. Spin-orbit coupling : Done. 2018-Feb-01
*. surface calculation, edge calculation : Done. 2018-Feb-14 
*. Coordinate system when reading POSCAR : direct, cartesian (not available now...) : Done. 2018-Apr-11
     For cartesin: see SVDINVERSE routine which makes lattice vector matrice inversion
     (r1,r2,r3) = inv(transpose(lattmat)) * transpose((coord_x, coord_y, coord_z))
*. When reading parameter either from file or INCAR-TB, it will be better to
   write also the comment starting with "#" mark, so that one can easily
   recognize what kind of interaction parameter it is. Done. 2018-Mar-??
*. Berry curvature calculation : Done. 2018-Jun-18
*. eigenstate wavefunction plot routine
     A. non magnetic case    : 2018-Jan-15
     B. spin polarized case  : 2018-Jun-11