4. Input files

4.1. cluster.ini

Configuration for cluster

Example for cluster.ini:

[INPUT]
MAXBODY    = 4
TRUNCATION = 2

4.2. getconf.ini

Configuration for getconf.
getconf calculate total energy of poscar.spin using ecicar by default.
If CORRDUMP tag is specified, getconf output correlation functions of poscar.spin.
If cluster.out already exists, you can skip over making it by specifying CLUSTEROUT tag.

Example for getconf.ini:

[INPUT]
SPINCE        = -1 1
SPINPOSCAR    = -1 1
CORRDUMP      = 1
CLUSTEROUT    = 1

4.3. metropolis.ini

Configuration for metropolis

Example for metropolis.ini:

[INPUT]
SPINCE        = -1 1
SPINPOSCAR    = -1 1
MCSTEP        = 10
SAMPLESTEP    = 10
TEMPERATURE   = 700

4.4. wang-landau.ini

Configuration for wang-landau

Example for wang-landau.ini:

[INPUT]
SPINCE        = -1 1
SPINPOSCAR    = -1 1
FLATCHECKSTEP = 100
MCSTEP        = 100
LOGFACTOR     = 4
LOGFLIMIT     = 0.0000001
BIN           = 255
EMIN          = -1
EMAX          = 1
FLATCRITERION = 0.8
CHEMIPOT      = 0 1 # sgc mode

4.5. directZ.ini

Configuration for directZ

Example for directZ.ini:

[INPUT]
SPINCE        = -1 1
SPINPOSCAR    = -1 1
MCSTEP        = 100
FLATCHECKSTEP = 100
LOGFACTOR     = 4
LOGFLIMIT     = 0.0000001
BIN           = 200
TMIN          = 0
TMAX          = 8
TMOVELIMIT    = 4
FLATCRITERION = 0.8

4.6. Other input files

4.6.1. poscar.in

Input POSCAR file for cluster. The number of spins and those positions should be set.

Example for poscar.in:

POSCAR fcc
1.0
    4.00000000000000      0.00000000000000      0.00000000000000
    0.00000000000000      4.00000000000000      0.00000000000000
    0.00000000000000      0.00000000000000      4.00000000000000
 4
Direct
    0.00000000000000      0.00000000000000      0.00000000000000
    0.50000000000000      0.50000000000000      0.00000000000000
    0.00000000000000      0.50000000000000      0.50000000000000
    0.50000000000000      0.00000000000000      0.50000000000000

4.6.2. poscar.spin

Initial spin configuration for MC simulations. The number of spins for each composition and those positions should be set.

Example for poscar.spin:

POSCAR spin fcc
1.0
    4.00000000000000      0.00000000000000      0.00000000000000
    0.00000000000000      4.00000000000000      0.00000000000000
    0.00000000000000      0.00000000000000      4.00000000000000
 2 2
Direct
    0.00000000000000      0.00000000000000      0.00000000000000
    0.50000000000000      0.50000000000000      0.00000000000000
    0.00000000000000      0.50000000000000      0.50000000000000
    0.50000000000000      0.00000000000000      0.50000000000000

4.6.3. ecicar

Effective cluster interactions (ECI) for MC simulations. ECI should be consistent with basis functions.

Example for ecicar in binary system:

0 0
1 0.1
2 0.05
3 -0.02
6 0.01
...

Example for ecicar in ternary system:

0 0
1 0.1 0.2 0.1
2 0.05 0.2 0.3
...

4.7. Tags

4.7.1. MAXBODY

Maximum number of sites to be searched. MAXBODY should be 4 or less.

4.7.2. TRUNCATION

Maximum distance (angstrom) to be searched.

4.7.3. PAIRTRUNC

Maximum distance (angstrom) to be searched for pair cluster.

4.7.4. TRITRUNC

Maximum distance (angstrom) to be searched for triplet cluster.

4.7.5. QUADTRUNC

Maximum distance (angstrom) to be searched for quadruplet cluster.

4.7.6. CORRDUMP

If CORRDUMP >= 1, program outputs correlation functions instead of total energy.

4.7.7. CLUSTEROUT

If CLUSTEROUT >= 1, program uses cluster.out which is already outputed by cluster.

4.7.8. SPINCE

Spin variables for each compositions.

4.7.9. SPINPOSCAR

Spin variables for each compositions in poscar.spin.

4.7.10. MCSTEP

Number of steps per site to propose a new state and accept/reject it via single-spin-flip/pair-spins-exchange. In order to make the system equilibrium, this tag is important.

4.7.11. SAMPLESTEP

Number of steps per site that samples total energy of the system. In order to calculate internal energy with good accuracy, the system should have been reached to equilibrium state [CE2].

4.7.12. TEMPERATURE

Temperature at which the simulation is done. There are two ways to specify the tag.

One is to specify one temperature at which the simulation is done.:

TEMPERATURE   = 700

Another is to specify three values; first is the initial temperature, second is the step one, and final is the last temperature.:

   TEMPERATURE   = 900 100 100 # temperature decreases from 900K to 100K.
or TEMPERATURE   = 100 100 900 # vice versa.

4.7.13. FLATCHECKSTEP

Every FLATCHECKSTEP, the simulation checks whether the histogram is flat according to FLATCRITERION tag.

4.7.14. FLATCRITERION

The definition of histogram flatness; if all possible histograms are larger than FLATCRITERION of the average of H(E), the histogram is regarded as flat.

4.7.15. LOGFACTOR

Initial logarithm of the factor.

4.7.16. LOGFLIMIT

Final logarithm of the factor.

4.7.17. BIN

Number of bins.

4.7.18. EMIN

The minimum of total energy where the simulation constructs the density of states.

4.7.19. EMAX

The maximum of total energy where the simulation constructs the density of states.

4.7.20. SPININPUT

Initial spin configuration file.

SPININPUT      = macrostate.in

4.7.21. CHEMIPOT

Chemical potentials for each composition. If this tag is set, ensemble is automatically changed from canonical to semi-grand-canonical, i.e. the sampling procedure is changed from a pair-spins exchange to single-spin-flip.:

CHEMIPOT      = 0 1 # sgc mode

4.7.22. TMIN

The minimum of temperature where the simulation can reach.

4.7.23. TMAX

The maximum of temperature where the simulation can reach.

4.7.24. TMOVELIMIT

The number of BIN the random walker can reach in one step.

4.7.25. PROBABILITYBYT

The probability that the similation select the type of move, energy move or temperature move.