Thermoelectric Effect - Adding the physics

Hello,

I'm working in a project on thermoelectric generator. As 'Thermoelectric' physics interface,is not in the physics area/physics list, I was trying to add the physics using the steps given in the COMSOL Help. But, I'm getting an error in the weak equation in feature1, 'Syntax of Expression is wrong'. The expression is K.del(T).Test(del T), (where del is the symbol Capital Delta). Could anyone please help me in finding out the solution.

Thank you
Pheba Cherian