[Pw_forum] RELAX: problem in finding the lowest energy structure

[ZARA NBSH]

Dear all,
I would like to study the interaction ​between 2 organic molecules, contain
O, H and C atoms.
As the first step  I relaxed the structure. My problem is that after
finishing the run it couldn't find the lowest energy structure.
And I could find some new structures, by hand, with a lower energies.
 The energy difference (about 0.1 eV) is strongly higher than the accuracy
of my calculations and also the structures are very different.
in my calculations the vacuum is large enough and the force convergence is
1D-5.

My question is how can I find the lowest energy structure?

Best regards,
Zara
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