▁j aw ▁also ▁distinguish ▁Min as el ates ▁from ▁E pi ph rag m op hora . ▁ ▁References ▁ ▁Category : E pi ph rag m op hor idae ▁Category : G ast rop ods ▁described ▁in ▁ 2 0 1 7 <0x0A> </s> ▁In ▁chem istry , ▁au roph il icity ▁refers ▁to ▁the ▁t endency ▁of ▁gold ▁complex es ▁to ▁aggregate ▁via ▁formation ▁of ▁weak ▁metal lo ph il ic ▁interactions . ▁ ▁The ▁main ▁evidence ▁for ▁au roph il icity ▁is ▁from ▁the ▁cry stal log raph ic ▁analysis ▁of ▁Au ( I ) ▁complex es . ▁ ▁The ▁au roph il ic ▁bond ▁has ▁a ▁length ▁of ▁about ▁ 3 . 0   Å ▁and ▁a ▁strength ▁of ▁about ▁ 7 – 1 2   k cal / m ol , ▁which ▁is ▁compar able ▁to ▁the ▁strength ▁of ▁a ▁hydro gen ▁bond . ▁The ▁effect ▁is ▁greatest ▁for ▁gold ▁as ▁compared ▁to ▁co pper ▁or ▁silver — the ▁higher ▁elements ▁in ▁its ▁periodic ▁table ▁group — due ▁to ▁increased ▁relativ istic ▁effects . ▁Observ ations ▁and ▁theory ▁show ▁that , ▁on ▁average , ▁ 2 8 % ▁of ▁the ▁binding ▁energy ▁in ▁the ▁au roph il ic ▁interaction ▁can ▁be ▁attributed ▁to ▁relativ istic ▁expansion ▁of ▁the ▁gold ▁d ▁orbit als . ▁ ▁An ▁example ▁of ▁au roph il icity ▁is ▁the ▁prop ens ity ▁of ▁gold ▁cent res ▁to ▁aggregate . ▁ ▁While ▁both ▁intr am ole cular ▁and ▁inter m ole cular ▁au roph il