Pablo Piaggi

I noticed that there are no examples in the documentation of [MCOLV_COMBINE](https://www.plumed.org/doc-master/user-doc/html/_m_c_o_l_v__c_o_m_b_i_n_e.html) and it would be nice to add one. Furthermore it seems that one cannot use more than two...

Hello, we have successfully compiled and linked libnxc with libxc and QuantumEspresso. What string should we pass to QuantumEspresso's "INPUT_DFT" in order to use the xcdiff functional? Perhaps this information...