fitfc

FIT Force Constants 3.48, by Axel van de Walle
   -f            Fit force constants (otherwise, generate pertubations) (Default: Off)
  -si=[string]   Input file defining the ideal structure (default: str.out)
  -sr=[string]   Input file defining the relaxed structure (default: str_relax.out)
  -er=[real]     Minimum distance between displaced atoms (Default: 0)
-ernn=[real]     Minimum distance between displaced atoms in multiple of nearest neighbor distance 
                     (Default: 0)
  -fr=[real]     Force constant range (Default: 0)
-frnn=[real]     Force constant range (in multiple of nearest neighbor distance) (Default: 0)
  -dr=[real]     Displacement of the perturbed atom (default: 0.2)
  -ms=[real]     Strain of the maximum volume sampled (default: 0.01)
  -dv            Specified strain above is volumetric (Default: Off)
  -ns=[int]      Number of volume sample (default: 2)
  -iu            Include Unperturbed structure in generated structures (Default: Off)
 -nrr            Do not rerelax structures at each new volume (Default: Off)
  -cs            Check for Singular matrix in fit (Default: Off)
 -ncs            No check for singular matrix in fit (this is the default, option included for 
                     backward compatibility) (Default: Off)
  -wm            Write fitting Matrices (Default: Off)
  -sf=[string]   Extra strain file (Default: )
   -m=[string]   Input file defining the atomic masses (default: ${atatdir}/data/masses.in)
  -T0=[real]     Minimum temperature (default: 0) 
  -T1=[real]     Maximum temperature (default: 2000)
  -dT=[real]     Temperature step (default: 100)
   -P=[real]     Pressure (in GPa, default: 0)
  -kp=[real]     Number of k-points per reciprocal atom (default: 1000)
  -kx=[int]      k-point mesh (along 1st recip lat. vect.) if <>0 then overrides -kp=... (Default: 
                     0)
  -ky=[int]      k-point mesh (along 2nd recip lat. vect.) (Default: 0)
  -kz=[int]      k-point mesh (along 3rd recip lat. vect.) (Default: 0)
  -fp=[int]      Power of polynomial to fit free energy (Default: -1)
  -s0            Use a gamma-centered k-point mesh (default shift: 1/2 1/2 1/2) (Default: Off)
  -sx=[real]     k-point shift (along 1st recip lat. vect.) (Default: 0.5)
  -sy=[real]     k-point shift (along 2nd recip lat. vect.) (Default: 0.5)
  -sz=[real]     k-point shift (along 3rd recip lat. vect.) (Default: 0.5)
  -df=[string]   Phonon dispersion curve calculation input file. (Default: )
  -hp=[real]     Planck's constant (default in (eV s))
  -kb=[real]     Boltzman's constant (default in eV/K)
 -cfk=[real]     Conversion factor for force constants into energy/dist^2 (default: converts eV/A^2 
                     into J/m^2)
  -mu=[real]     Mass units (default: converts a.u. mass into kg)
  -rl=[real]     Robust Length algorithm parameter for soft modes (beta) (Default: 0)
 -rls=[real]     Quadratic strain-dependence of robust length for positive strain (beta) (Default: 
                     0)
  -cP=[real]     Conversion factor from pressure*volume into eV (Default: 0.00624151)
  -pa            Output free energy per atom instead of per unit cell (Default: Off)
  -pe            Print energy in 3rd column of fitfc.out (Default: Off)
  -sc=[real]     Correction factor if spectator ion are present (default: 1)
 -me0            Subtract energy at 0K (Default: Off)
  -no            Print number of atom in supercell only (Default: Off)
  -w1            Flag first perturbation wait1 instead of wait file (Default: Off)
  -w2            Flag negative perturbation directions with wait2 instead of wait file (Default: 
                     Off)
  -fn            Force continuation of calculations even if unstable (Default: Off)
  -fu            Find unstable modes (Default: Off)
  -gu=[int]      Generate unstable modes number n (Default: 0)
  -gn            Also Generate Negative displacements for mode specified by -gu=... (Default: Off)
 -mau=[int]      Maximum number of atom per supercell for unstable mode generation (Default: 64)
 -sfc=[int]      Simplify force constants: 1=streching+bending, 2=symmetric (Default: 0)
 -apd            Atom-Projected DOS (Default: Off)
 -sig=[int]      Number of significant digits printed (default: 5)
   -z=[real]     Tolerance for finding symmetry operations (default: 1e-3)
   -h            Display more help (Default: Off)