Problem: successive displaced geometries in the logfile are numbered, but in your case these numbers make sudden jumps, like '0, 1, 2, 5, 6, 13...'
Cause: you're using Cartesian displacements in a system that has some symmetry in its equilibrium geometry. The program skips the displacements of symmetry-equivalent atomic coordinates to save time. The displacement counts in the logfile do not run over the actually performed displacements but over all atomic coordinates that could be displaced if no use were made of symmetry properties.
Cure: there is no error, don't worry.
