1. Overview of CLUPAN¶
1.1. Cluster expansion method and thermodynamic calculations using CLUPAN¶
- Evaluation of effective cluster interactions (ECI) using the cluster expansion (CE) method.
- Calculation of energies for structures using ECI.
- Monte Carlo simulations using ECI.
- Free energy calculation based on thermodynamics integration combined with Monte Carlo simulations.
- Iterative procedure to perform the CE.
See [CE1] to find the details of the procedure.
|[CE1]||A Seko, Y Koyama and I Tanaka, Phys. Rev. B 80, 165122 (2009).|
1.2. Framework of CLUPAN¶
CLUPAN is composed of the following programs.
- Searching for symmetrically-independent structures
- Searching for symmetrically-independent clusters
- Calculating correlation functions of a structure
- Estimating ECIs using the least-squares method
- lsf, wlsf
- Optimizing cluster set using the genetic algorithm and the simulated annealing
- gasa, wgasa
- Searching for DFT structures that improves the estimated ECIs
- Searching for ground state structures using the ECIs
- Performing Monte Carlo simulations using the ECIs
- cmc, gcmc
- estimating the grand potential using the thermodynamic integration
- Evaluating the variance of correlation functions and the correlation between correlation functions of two clusters
- Calculating the mean variance of the predicted energy
- Generating VARIANCE and MEAN files required in search_poscar_variance
- Estimating the grand potential using the low temperature expansion
1.3. Examples of calculations by using CLUPAN¶
Predicting cation disordering in spinel oxides [CE2]
Exploring stable structures in tin oxides [CE3]
|[CE2]||A Seko, K Yuge, F Oba, A Kuwabara and I Tanaka, Phys. Rev. B 73, 184117 (2006).|
|[CE3]||A Seko, A Togo, F Oba and I Tanaka, Phys. Rev. Lett. 100, 045702 (2008).|