How do I predict the structure of a nanoparticle with Calypso and Quantum ESPRESSO?

I want to create a nanoparticle of CuO and predict it’s structure. I’ve done unit cell relaxation with Quantum ESPRESSO. One tool to predict nanocluster structure is Calypso which is PSO-based. I’m using Quantum ESPRESSO with it. If anyone does Calypso structure prediction, what are some ways for predicting nanocluster structure?
I want to use this nanostructure to calculate TDDFT and some other optical properties.

If there is any other way to predict a nanoparticle’s structure (without Calypso) please let me know.