is there any mnemonic for the AXE method?

One method of helping to understand molecular shapes is the AXyEznotation.

Adenotes the central atom of the molecule.
Xyshows how many atoms are around the central atom
Ezshows how many pairs of electrons (lone pairs only) are around the central atom


Learn to draw theAXnE0series:

Nomenclature

The last step is to add the nomenclature. First of all you should take in account that the lone pair (E) don't appear as a part of the final shape from which the nomenclature is derived. If not considering theEgroup you obtain aplanarmolecule you have to add the wordplanarafter the name, if you obtain a pyramidal shape you should usepyramidalafter the name of the planar pyramid's base