# Defining native gate dictionary in pyGSTi

In pyGSTi in order to construct Randomized Benchmarking circuits, we first need to define a pspec object that contains information about the number of qubits, basis gates and gate availability.*

In the tutorial notebooks (https://github.com/pyGSTio/pyGSTi/blob/master/jupyter_notebooks/Tutorials/algorithms/RB-DirectRB.ipynb), they use a predefined gate dictionary for this, where each gate is called by a certain key (string) and it's value corresponds to the numpy array for the matrix representation of the gate. This does not seem to allow parametrized gates but if we want to characterize for example an ibmq device, then we would need a dictionary for continuously parametrized gates.

I would be really happy, if someone knows how to define a pspec object so that it corresponds to the device, I want run the experiments later on.

*(Interestingly the qubit topology doesn't play a role here, but the sampling algorithms for direct and mirror randomized benchmarking need to work with the topology of the device in order to achieve the desired sampling process of single- and two-qubit gate layers...)