AronI read about a lead-free "perovskite" and thought of you @breter_j 
#NotPerovskite https://pubs.acs.org/doi/full/10.1021/acs.jpclett.2c03586
#NotPerovskite https://pubs.acs.org/doi/full/10.1021/acs.jpclett.2c03586
J Breternitz@lonepair yep, one of those well-known tetrahedral perovskites.
Wait for our future publications on kestero-perovskites...