What is the reason for the difference in frame number?

Hello,

I'd like to ask about something strange from my results.

When I used dmol3 tool for calculation, finished with no error, there was difference between the number of steps(frames) in xcd/outmol and in xsd/xtd.

In graph of xcd, the calculation was done with 4 steps, however, there was 5 frames in xtd file.

Also, the outmol file gives info only about first 4 stpes not the last one while xsd shows data of fifth frame.

What is the reason of this and how can I fix it?

Thank you for any of comments in advance.