frustration

https://doi.org/10.1351/goldbook.14220
Feature of crystalline packing characterized by different crystalline arrangements of chain stems at two (or more) sites that would be expected to be equivalent.
Note: The term "frustration" signifies that some chains can achieve the minimum energycconformation or an optimal packing arrangement, while others cannot.
Example: A crystalline polymer structure exhibiting frustration is the \(\ce{\upbeta\mbox{-}polymorph}\) of isotactic polypropylene.
Source:
PAC, 2011, 83, 1831. (Definitions of terms relating to crystalline polymers (IUPAC Recommendations 2011)) on page 1845 [Terms] [Paper]