If the interaction energy between a sodium ion and a chloride ion in table salt is 760 kJ/mol, what is the interaction energy between a zinc ion

If the interaction energy between a sodium ion and a chloride ion in table salt is 760 kJ/mol, what is the interaction energy between a zinc ion (Zn2+ ) and a sulfide ion (S2 ) in a hypothetical structure in which the inter-ionic distances are the same as that of NaCl