Question: how pcl5 exist in solid state?
Answer: Answers : (4) in solid state pcl5 prefer to exist as oppositely charged ions like [pcl4]- and [pcl6]- as the ionic bonding enhances the crystalline nature . also [pcl4]- is tetrahedral , while [pcl6]- is octahedral . ... So these structure fit well into each other providing extra stability to solid structure.