Off diagonal Jacobian term for Grain Growth Elastic Driving Force Model

[cxr...@outlook.com]

Hello all, 

I am wondering if the Off diagonal Jacobian term is implemented in MOOSE for Grain Growth Elastic Driving Force Model, Like PhaseFieldFractureMechanicsOffDiag for fracture model? When I am coupling plasticity with grain growth model, the convergence is always very bad. Could the Off diagonal Jacobian term be the reason for bad convergence? Thanks.

Xiaorong