Differences

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--- fweight [2013/03/05 07:48] – created daniel
+++ fweight [2018/01/02 16:49] (current) – daniel
@@ Line 13: / Line 13: @@
 This can be a problem for very small reference values. By enabling the ''fweight'' compile option, each force component $F_k$ is weighted by the factor
-$$u_k=\frac{1}{\boldsymbol F_k^2+\epsilon}$$
+$$u_k=\frac{1}{(\boldsymbol F_k^0+\epsilon)^2},$$
-This increases the importance of numerically small forces.
+where $\boldsymbol F_k^0$ is the magnitude of the force vector for atom $k$.
-The compile time parameter FORCE_EPS (in ''potfit.h'') prevents the overweighting of very tiny forces. The default for this value is 0.1.
+This increases the relative contributions of numerically small forces to the error sum.
+The compile time parameter FORCE_EPS (in ''defines.h'') prevents the overweighting of very tiny forces. The default for this value is 0.1.