Input

In the following a short sketch on the old inp file is provided:

Description of an example "inp" file

Note that we use atomic units, i.e. the length is in Bohr-radii (1 a.u. = 0.5291772108(18) Å) and the energy is in Hartree: 1 htr = 2 Ry = 27.2113845(23) eV. For bulk or film calculations, the energy zero is the average interstitial potential or the vacuum energy, respectively.

The inp file

[01][11]|strho=T,film=T,dos=F,isec1=99,ndir= 0,secvar=F  
[02][12]|Cu 3l    tests  
[03][13]|squ p4m ,invs=T,zrfs=T,invs2=T,jspins=1,l_noco=F,l_J=F  
[04][14]|   4.82381  
[05][15]| 12.000000 15.000000  1.000000  
[06][16]|rpbe   non-tivistic  
[07][17]|igrd=1,lwb=F,ndvgrd=6,idsprs=0,chng= -.100D-11  
[08][18]|iggachk=0,idsprs0=0,idsprsl=0,idsprsi=0,idsprsv=0  
[09][19]| 2  
[10][20]|**********************************  
[11][21]|Cu  29    7    8  421  2.150000   .023  
[12][22]|  
[13][23]| 1,force =F,nlo= 0,llo=  
[14][24]|   .000000   .000000   .000000  1.000000  
[15][25]|**********************************  
[16][26]|Cu  29    7    8  421  2.150000   .023  
[17][27]|  
[18][28]| 2,force =T,nlo= 0,llo=  
[19][29]|  .500000   .500000  3.050000  1.000000  
[20][30]|   .500000   .500000 -3.050000  1.000000  
[21][31]|**********************************  
[22][32]| 10.500000 10.000000  
[23][33]|vchk=F,cdinf=F,pot8=F,gw=0,numbands=  0  
[24][34]|lpr=0,form66=F,l_f=F,eonly=F,eig66=F,soc66=F  
[25][35]|  8  8  
[26][36]|  1  0  
[27][37]|Window # 1  
[28][38]|  -1.00000   0.20000  33.00000  
[29][39]|   3.80000  
[30][40]|gauss=F    .0020 tria=F  
[31][41]|   0.00000   0.00000,l_soc=F,spav=F,off=F,01  
[32][42]|frcor=F,slice=F,ctail=F,disp=F,kcrel=0,u2f=F,f2u=F,bmt=F  
[33][43]|itmax= 8,maxiter= 19,imix= 7,alpha=  0.10,spinf=  1.00  
[34][44]|swsp=F  0.00  0.00  
[35][45]|lflip=F  1  1  
[36][46]|vacdos=F,layers= 1,integ=F,star=F,nstars= 0     0.00     0.00     0.00     0.00,nstm=0,tworkf=  0.000000  
[37][47]|  
[38][48]|iplot=F,score=F,plpot=F,band=F  
[39][49]|  0   .000000   .000000,nnne=  0,pallst=F  
[40][50]|xa=   2.00000,thetad= 300.00000,epsdisp=    .00010,epsforce=    .00010  
[41][51]|relax 000 001  
[42][52]|emin_dos=  -0.50000,emax_dos=   0.50000,sig_dos=   0.01500  
[43][53]|nkpt=   20  
[44][54]|nqpt=  200  
ALTERNATIVELY  
[43][53]|nkpt=   20,nx=06,ny=06,nz=06,gamma=F  
[44][54]|nqpt=  200,qx=06,qy=06,qz=06

(1)

strho =[T,F] if true, a starting-density is generated
 film  =[T,F] selects film (T) or bulk (F) calculations
 dos   =[T,F] generate dos-output file dosinp and stops
 isec1 =[0-99] iterative diagonalization used after iteration# isec1
 ndir  =[0-5]  if dos=T and ndir>0, calculate symmetry information for 
               bandstructures; indicates which symmetry operations to use.
               In version 22o and higher this has new behaviour!!!!!!
 secvar=[T,F]  non-spherical Hamiltonian treated in second variation

(2) Title and/or comment line

(3)

latnam=[squ,p-r,c-r,hex,hx3,...] selects type of lattice 
 spgrp =[p4m ,pmm ,cmm ,p3m1,...] selects space-group
 invs  =[T,F] T, if the system has inversion-symmetry  
 zrfs  =[T,F] T, if the system has z-reflection symmetry 
 invs2 =[T,F] T, if the vacuum planes have 2-dimensional inversion-s.
 jspins=[1,2] numer of spins: paramagnetic (1) or magnetic (2) calculation 
 l_noco=[T,F] T, if non-collinear calculation (prepare file 'nocoinp')
 l_J=[T,F] T for a calculation of Heisenberg Jij parameters (goes with l_noco=T)

(4) in-plane lattice constant(s) (alternatively the bravais lattice matrix can be given)

a1 (,a2)

(5) c-axis

- in case of bulk -
  c-axis   lattice constant
  c-axis   lattice constant
  scale    scaling factor for all lattice constants & z-coordinates 
 - in case of film -
  dvac     vacuum boundary (for film=T, otherwise dvac=dtild)
  dtild    z-boundary for 3D-planewave box ( > dvac !)
  scale    scaling factor for all lattice constants & z-coordinates

(6) Exchange Correlation Potential settings

xc-potential=[x-a, mjw, [![Symbol - externer Link][64]pz][64], [![Symbol - externer Link][65]bh][65], wign, hl, [![Symbol - externer Link][66]vwn][66], xal, [![Symbol - externer Link][67]l91][67], [![Symbol - externer Link][68]pw91][68], [![Symbol - externer Link][69]pbe][69], [![Symbol - externer Link][70]rpbe][70], [![Symbol - externer Link][71]Rpbe][71]]
 relativistic ... uses relativistic corrections of [![Symbol - externer Link][72]MacDonnald-Vosko][72].

Please note that relativistic corrections in conjunction with the GGA are currently not implemented.

(7)

igrd  =[0,1]   igrd=0: no gradient correction 
 lwb   =[T,F]   use White & Bird trick (disabled)
 ndvgrd=[2,4,6] grid partition for calculation of derivatives
 idsprs=[0,1]   general GGA print-switch
 chng  =        lowest allowed density value to before stop

(8) various GGA print-switches

(9)

ntype =[0-99] number of atom types

(10) separator

(11) Atom

Name of atom type     [Va, H,...,Lw]
 Nuclear Number        [ 0, 1,...103]
 number of core levels [typically 1,3,7,...]
 l-expansion cutoff    [typically 6-12]
 muffin-tin gridpoints [odd number, typically > 301]
 muffin-tin radius     [choose non-overlapping]
 logarithmic increment [for normal radii & meshes 0.02 -0.03]

(12) input line for LDA+U

(13)

number of equivalent atoms in this atom type
 force =[T,F]          calculate forces on this atom-type
 nlo   =[0-99]         number of local orbitals to use
 llo   =[0-99],...     l-values for local orbitals

(14) Positions

x,y,z coordinates of atom (x&y always in internal (relative) units, if film=F also z)
 scale    scales coordinates by 1/scale. If film=T, scales only x&y coordinates, if film=F also z

(15-20) same as (10-14) for the second atom type

(21) separator

(22) Planewave cutoff

gmax         cutoff for PW-expansion of potential & density  ( > 2*kmax)
 gmaxxc       cutoff for PW-expansion of XC-potential ( > 2*kmax, < gmax)

(23) logical switches

vchk    =[T,F]   check continuity of potential at muffin-tin & vacuum boundary
 cdinf   =[T,F]   calculates partial charges and continuity of density
 pot8    =[T,F]   if T, use potential from files pottot and potcoul
 gw      =[0,1,2] controls the ouptut for the GW code Spex 
 numbands= N      sets the maximal number of bands to N

(24) logical switches

lpr   =[0,1] if lpr.gt.0, then also list eigenvectors on output file
 form66=[T,F] gives a formatted eigenvector file (eig)
 l_f   =[T,F] calculate pulay-forces on atoms, otherwise only HF-force
              master switch for Geometry optimizer
 eonly =[T,F] if T, no eigenvectors are dumped on file 'eig'
 eig66 =[T,F] if T: if 'eig' file exists use eigenvalues and -vectors from 'eig',
                    if 'eig' file does not exist create it and stop
 soc66 =[T,F] relevant only for spin-orbit calculations with eig66=T

(25) l-cutoffs for the non-spherical Hamiltonian for all atom-types.

Notice that this is assumed to be < 10.

(26) old switches (do use with maximum care)

number of windows [1,2 or more]
 lepr=[0,1] energyparameters given on absolute (0) or floating (1) scale

(27) separator for each window (lines 27 to 29 are repeated for each window)

(28) Energy window

lower energy boundary for eigenvalues (in hartree units)
 upper  (these boundaries are not used on the Cray or if invs=F)
 number of electrons in the window

(29) cutoff for Plane wave expansion of wavefunctions

kmax determines basis size

(30) Fermi energy, k-integration, weights

gauss=[T,F] use gaussian smearing for calculation of fermi-energy & weights
             if gauss=F & tria =F fermi smearing is used (recommended for self-consistency) 
 tkb  =      temparature for smearing with gauss or fermi-smearing method
 tria =[T,F] use triangular method (2D version of tetrahedron method).

(31) SOC switches

theta,phi   angles to specify the  spin-quantization axis if l_soc=T
 l_soc=[T,F] use spin-orbit coupling
 spav =[T,F] construct spin-orbit operator from spin-averaged potential
 off  =[T,F] only soc contributions from certain muffin tins are considered
             (atom types are specified by binary number)

(32) more switches

frcor=[T,F] if T, use frozen core approximation
 slice=[T,F] if T, calculate a slice (parameters in line (39)
 ctail=[T,F] if T, make core-tail correction (reexpansion of core-tails)
 disp =[T,F] if T, calculate the distance of in- and output potential
 kcrel=[0,1] for 0 (1), a fully-relativistic (spin-polarized) core routine is used
 u2f  =[T,F] generates a formatted density/potential from unformated file f_unf
 f2u  =[T,F] generates unformatted files from formatted cdn_form
 bmt =[T,F] generates density 'cdnbmt' with magnetization in interst. and vac. set to zero

(33) Mixing

itmax  =[1-99]    number of iterations done in this run
 maxiter=[0-99]    number of iterations used for broyden-mixing 
 imix   =[0,3,5,7] type of mixing (straight, Broyden 1st and 2nd or Anderson)
 alpha  =[0.-0.99] mixing factor (if > 10.0, only mixing is performed)
 spinf  =[1-100.0] spin mixing factor enhancement

(34) Initial magnetic moments

swsp=[T,F]    if T, generate spin-polarized density from unpolarized 
 bmu's         moments of atom-types generated if swsp=T

(35) Flip spins

lflip=[T,F]   if T, flip spin-direction for selected atoms
 nflip=[-1,1]  flip spin-direction for atom-types where nflip=-1

(36) Layered vacuum DOS

vacdos=[T,F]  if T, in case of dos=T also the dos in the vacuum region is calculated
 layers=[0-99] number of layers, in which the vacuum dos is integrated (see next line)
 integ =[T,F]  if T, vacuum dos is integrated also in  z-direction
 star  =[T,F]  if T, star coefficients are calculated at values of izlay for 0th (=q) to nstars-1
 nstars=[0-99] number of star functions to be used (0th star is given by value of q=charge integrated in 2D)
 locx, locy: four real numbers that can be used to calculate local DOS at a certain vertical position z 
     (or integrated in z) within a restricted area of the 2D unit cell, the corners of this area is given 
     by locx and locy they are defined in internal coordinates
 nstm  =[0-2] 0: s-Tip, 1: p_z-Tip, 2: d_z^2-Tip (following Chen's derivative rule)
 tworkf= Workfunction of Tip (in hartree units) is needed for d_z^2-Orbital)

(37)

if integ=T this line defines the z_low and z_up for integration (in internal units)
 otherwise the z_values of the planes are entered.

(38) Charge/ Potential plotting

iplot=[T,F]   calculate a charge density plot
 score=[T,F]   if T, excludes the core-charge from the plot
 plpot=[T,F]   allows to plot the potential from potential-files
 band =[T,F]   simplifies the creation of band structure plots

(39) Charge density slicing

number of k-point which is used for a [slice][96] (k=0 : all k-points taken)
 lower boundary for eigenvalues in the slice 
 upper -"-
 nnne  = number of eigenvalue used for the slice (nnne=0 : all eigenvalues between boundaries taken)
 pallst=[T,F] set true if one plots states which lie above the fermi level

(40) Geometry optimizer

xa      = mixing parameter for geometry optimizer (2. or 3. is a good choice)
 thetad  = debye temperature used for first geometry optimization step
 epsdisp = if all displacements are < epsdisp, the program stops
 epsforce= f all forces  are < epsforce, the program stops

(41) Geometry optimizer

relax: for each atom-types a triple of 0's or 1's specifies if the (x,y,z)
 coordinates can be relaxed; i.e. 001 means that only relaxation in z-direction is 
 allowed.

(42) DOS output parameter

emin_dos= set lower boundary of energy window of the DOS plot
 emax_dos= set upper boundary of energy window of the DOS plot
           (both values only affect the plot, not the energy window of eigenvalues specified above)
 sig_dos = Gaussian smearing factor used in the plot (if tetrahedron method is not used)

(43) k-points mesh (to be generated if not already existent)

nkpt      =  number of IBZ k-points to be generated (only very rough estimate; only used if nx/ny/nz not specified.)
 nx,ny,nz  =  x/y/z mesh for equidistant full BZ mesh to be generated. (This is optional, see above.)
 gamma     = [T,F] is a optional keyword; if true a k-point set will be generated, which includes the Gamma point as the  
                   first k-point

(44) Spin-spirals (qss) mesh, generated if not already existent

nqpt     = number of IBZ qss to be generated (used only if qx/qy/qz not specified)
  qx,qy,qz = x/y/z mesh for equidistant full BZ qss mesh to be generated (This is optional, see above).