6. Calculation of correlation functions¶
6.1. correlation¶
- Calculating correlation functions for a structure.
- Crystal lattice is determined by UPOSCAR and UPOTCAR files.
- Clusters for calculating correlations functions are specified by position.out.
- Available only for binary systems.
- Available for multi-thread calculations using OPENMP.
Input files
- CE.in
- UPOSCAR
- UPOTCAR
- POSCAR
- POTCAR
- position.out
Output files
- correlation.out
- of.out
6.2. CE.in¶
Example
Calculating correlation functions for a structure with the lattice constructed by the 2x1x1 expansion of UPOSCAR. Spin values are set to 1 and -1 for Mg and Zn, respectively.
ISUB = 1
NUCELLPOSCAR = 2 1 1
NAMEPOT = Mg Zn
SPIN = 1 -1
6.2.1. ISUB tag¶
Sublattice indexes for performing the CE. The CE is performed on ISUBth lattice sites of UPOSCAR (line 6).
- Default : 1
- Example : ISUB = 1 3
6.2.2. NUCELLPOSCAR tag¶
Number of unit cells included in POSCAR.
- Default : none
- Example : NUCELLPOSCAR = 2 1 1
6.2.3. NAMEPOT tag, SPIN tag¶
Atom names and spin values for the atom names. Do not set spin values for atoms which are not used for the CE.
- Default : none
- Example : NAMEPOT = Mg Zn
- Example : SPIN = 1 -1
In the above example, spin values for Mg and Zn are 1 and -1, respectively.
6.2.4. SYMPREC tag¶
Numerical precision for searching for symmetry operations (unit: fractional coordinates).
- Default : 1e-5
- Example : SYMPREC = 1e-5