Hi,nC_VOF(c,t) is a cell macro and cannot be applied to a face. Instead, I'd recommend that you use F_UDMI(f,t,i) to store these cell values. You should be able to use this F_UDMI for your subsequent calculations. nPlease see this link from the Ansys Fluent Customization manual for additional information.nI hope this helps.nThank you.nKarthikn