**5. Conclusions**

The core structure of the vortices is studied for *<sup>s</sup>*±, *dx*<sup>2</sup>−*y*<sup>2</sup> symmetries (connected with interband and intraband antiferromagnetic spin fluctuation mechanism, respectively) and *s*++ symmetry (mediated by moderate electron-phonon interaction due to Fe-ion oscillation and the critical orbital fluctuation) using Eilenberger approach and compared with the experimental data for iron pnictides. It is assumed [99] that the nodeless *s*± pairing state is realized in all optimally-doped iron pnictides, while nodes in the gap are observed in the over-doped KFe2As2 compound, implying a *dx*<sup>2</sup>−*y*<sup>2</sup> -wave pairing state, there are also other points of view [10, 13]. The stoichiometrical LiFeAs, without antifferomagmetic ordering, is considered as a candidate for the implementation of the *s*++ symmetry. Different impurity scattering rate dependences of cutoff parameter *ξ<sup>h</sup>* are found for *s*<sup>±</sup> and *s*++ cases. In the nonstoichiometric case, when intraband impurity scattering (Γ0) is much larger than the interband impurity scattering rate (Γ*π*) the *ξh*/*ξc*<sup>2</sup> ratio is less in *s*<sup>±</sup> symmetry. When Γ<sup>0</sup> ≈ Γ*<sup>π</sup>* (stoichiometric case) opposite tendencies are found, in *s*<sup>±</sup> symmetry the *ξh*/*ξc*<sup>2</sup> rises above the "clean" case curve (Γ<sup>0</sup> = Γ*<sup>π</sup>* = 0) while it decreases below the curve in the *s*++ case. In *d*-wave superconductors *<sup>ξ</sup>h*/*ξc*<sup>2</sup> always increases with <sup>Γ</sup>. For *dx*<sup>2</sup>−*y*<sup>2</sup> pairing the nonlocal generalized London equation and its connection with the Eilenberger theory are also considered. The problem of the effective penetration depth in the vortex state for *d*-wave superconductors is discussed. In this case, the field dependence of *λeff* is connected with the extended quasiclassical state near the nodes of the superconducting gap.
