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algorithms [2013/03/04 08:20] – danielalgorithms:main [2018/01/10 18:01] (current) – daniel
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 ~~NOTOC~~ ~~NOTOC~~
 ====== Algorithms ====== ====== Algorithms ======
 +----
 +This page is a quote from the [[http://elib.uni-stuttgart.de/opus/volltexte/2008/3410/|PhD Thesis of P. Brommer]].
 ---- ----
  
-== Force Matching ==+=== Force Matching ===
  
 As described above, classical MD calculations require effective potentials, As described above, classical MD calculations require effective potentials,
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 The method of including forces from ab-initio calculations in the potential generation  The method of including forces from ab-initio calculations in the potential generation 
-is called **Force Matching** and was first described by Ercolessi and Adams<sup>1</sup>,+is called **Force Matching** and was first described by Ercolessi and Adams 
 +((Ercolessi, F. and Adams, J. B.: Interatomic Potentials from First-Principles Calculations: the Force-Matching Method. //Europhys. Lett.//, **26** (8), 583–588, 1994.)),
 where it was used to determine a glue potential for Aluminium. In the following section,  where it was used to determine a glue potential for Aluminium. In the following section, 
 this method is described in detail.  this method is described in detail. 
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 2.3.3 elaborates on this topic. 2.3.3 elaborates on this topic.
  
-== Optimisation ==+=== Optimisation ===
  
 Few mathematical topics have such a widespread effect on many subjects in Few mathematical topics have such a widespread effect on many subjects in
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 a well-known task with many well-documented algorithms. a well-known task with many well-documented algorithms.
  
-== compat-mode ==+---- 
 + 
 +=== compat-mode ===
  
 In older versions of //potfit// the error sum has been calculated as  In older versions of //potfit// the error sum has been calculated as 
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 $$Z_{F}(\boldsymbol\xi)=\sum_{k=1}^{m}[u_{k}(F_{k}(\boldsymbol\xi)-F^{0}_{k})]^2.$$ $$Z_{F}(\boldsymbol\xi)=\sum_{k=1}^{m}[u_{k}(F_{k}(\boldsymbol\xi)-F^{0}_{k})]^2.$$
  
-This behaviour can still be enabled by setting the ''compat'' compilation target.+This behaviour is no longer supported. The ''compat'' mode was removed with version 0.6.0.
  
-=== Algorithms available in potfit ===+==== Algorithms available in potfit ====
  
 Currently there are three optimization algorithms available: Currently there are three optimization algorithms available:
-  * [[Simulated Annealing]] +  - [[algorithms:simann|Simulated Annealing]] 
-  * [[Differential Evolution]] +  - [[algorithms:diffevo|Differential Evolution]] 
-  * [[Method of Least Squares]] (conjugate gradients)+  - [[algorithms:lsq|Method of least squares]] (conjugate gradients)
  
 Usually two of them are run subsequently, with the choice between 1 and 2, while 3 is always run. Simulatead Annealing can be used for both tabulated and analytic potentials, Usually two of them are run subsequently, with the choice between 1 and 2, while 3 is always run. Simulatead Annealing can be used for both tabulated and analytic potentials,
 Differential Evolution may run into troubles with tabulated potentials but works fine for analytic ones.  Differential Evolution may run into troubles with tabulated potentials but works fine for analytic ones. 
- 
------ 
- 
-1. Ercolessi, F. and Adams, J. B.: Interatomic Potentials from First-Principles Calculations: the Force-Matching Method. //Europhys. Lett.//, **26** (8), 583–588, 1994. 
- 
algorithms/main.1362381640.txt.gz · Last modified: 2013/03/04 08:20 by daniel