|
NOTE: The template orbitals MUST be generated with the external potetial background
(confining spheres of small negative potentials to mimic ions) as provided by the inp.dat file
which is generated by the inpgen.exe. inp.dat has to be kept in the same directory where
the scf anf nscf calculations are performed with tefield=.true. set in the scf and nscf input files of QE.
The basis generation code will stop if it can not find the inp.dat file in the orbital template directory.
Realistic satellite spheres as per the real localtion of neighboring atoms will improve description of basis.
Different atomic neighbourhood of same atoms may thus in principle require different template of orbitals. code : align_periodic.arb_orb_gh (download) Keywords : (click on the keywords to go to their description) orb_type_num (compulsory) orb_(1/2/..) (compulsory) sys_morph (compulsory) orb_box scf_output cell_param(compulsory if scf_output not set/available) sys_atom_num (compulsory if scf_output not set/available) sys_coords (compulsory if scf_output not set/available) gen_orbs(switchable) plot_xsf Description of keywords orb_type_num(compulsory) integer : number of types of orbitals to be considered as basis; no default orb_details(not used in this case) orb_1 character1(1) character2(1) integer1(1) { character3(1) character3(2) ... character3( integer1(1) ) } orb_2 character1(2) character2(2) integer1(2) { character3(1) character3(2) ... character3( integer1(2) ) } - - - orb_n character1(n) character2(n) integer1(n) { character3(1) character3(2) ... character3( integer1(n) ) } n : number of types of orbitals to be considered as basis character1(i) : X_Norb where 'X_' is symbol of the atom hosting the i-th orbital template (ex: "H_" or "He"), N is principal quantum number, "orb" is orbital type. Example : C_2sp2, where 'sp2' is a character string of length 3 used for example. It can be anything as per choice of user. character2(i) : path of directory where the i-th template orbtial file exists integer1(i) : multiplicity of the type of orbitals. Ex: 2/3/4 for sp/sp2/sp3 orbital type. character3(j) : name of the j-th orbital template file in the i-th type of orbitals no default set Ghost orbitals can be defined independently or as associated with any atom. Independent Ghost orbtials can be described by "X_" : "G1", "G2" etc. If "orb" in X_Norb is set to "rigid1" "rigid2" etc., then those orbitals are rigidly shifted to the atomic site, like as done for "s " type orbitals. They are not rotated for correct allignment as done for sp2 or pz orbitals. Ghost orbtials can only be of "s " or "rigid" type. Coordinates of independent ghost orbitals are to be mentioned under keyword sys_coords as: Gn x y z along with those of atoms of the system. If independent ghost orbtials are used then the keyword "sys_atom_num" must be followed by the total number of orbitals (atoms+ ghost orbitals) Ghost orbtials associated with atoms are to be mentioned as X_NG... where X is the associated atom and G is a compulsory indicator. In this case the coordinate of the host_atom at the input of inpgen can be different from that of the atom coordinate used in the scf calculation, and no confining potential need to be supplied. sys_morph(compulsory) character : '1d' '2d' '3d' depending on system geometry. Denotes nature of the system morphology. Needed to decide reference for alignement of orbtials. '1d' for strictly 1D system. '2d' for 2D and quasi-1D systems. '3d' for 0D and 3D systems. no default set orb_box real1(1) real2(1) real3(1) real1(2) real2(2) real3(2) - - - real1(n) real2(n) real3(n) n : number of orbital types suppled after orb_type_num real1(i) : length of side of box along x axis in which the i-th orbtial is constructed real2(i) : length of side of box along y axis in which the i-th orbtial is constructed real3(i) : length of side of box along z axis in which the i-th orbtial is constructed default 6Aangstrom for all sides scf_output character : name of the output file of the QE run which generated the KS states to be used to extract TB parameters. default set to 'non' Note: if not set or file not found then sys_atom_num and sys_coords are compulsory cell_param(compulsory if scf_output not set, not read otherwise ) x1(1) x1(2) x1(1) x2(2) x2(2) x2(2) x3(3) x3(3) x3(3) x1 x2 x3 are three lattice vectors sys_atom_num (compulsory if scf_output not set, optional otherwise ) integer : number of atoms in system ; use if system coordinate to be supplied externally, Note: Will overwrite atom symbols and coordinate read from scf output file, must be supplied for scf_output set to 'no' sys_coords(compulsory if scf_output not set, optional otherwise ) symbol(1) x(1) y(1) z(1) symbol(2) x(2) y(2) z(2) symbol(3) x(3) y(3) z(3) - - - - symbol(n) x(n) y(n) z(n) n : number of atoms supplied after sys_atom_num Note: Will overwrite atom symbols and coordinate read from scf output file, must be supplied for scf_output set to 'no' gen_orbs character: 'yes'/'YES' if not set then binary orbital files will not to be generated , only wcmap and axismap files will be available default set to 'no' plot_xsf character integer1 integer(1) integer(2) ... integer(n) character: 'yes'/'YES' integer1 : number(n) of orbitals to printed in xsf format for plotting (fort.9000+i files, i=1 to all orbitals) default set to 'no' |