Partial derivative is terms of Kronecker delta and the Laplacian operator

How can the following term:

## T_{ij} = \partial_i \partial_j \phi ##

to be written in terms of Kronecker delta and the Laplacian operator ## \bigtriangleup = \nabla^2 ##?

I mean is there a relation like:

## T_{ij} = \partial_i \partial_j \phi = ?? \delta_{ij} \bigtriangleup \phi.##

But what are ?? term

Any help is appreciated!

It cannot.

Orodruin said:

It cannot.

So there is no any way to simplify ## \partial_i \partial_j \phi ## ?

Not really no. Not without knowing more. In some special cases, perhaps, but not as a general rule.

What is the context here?