# 18.3. Output Fields

This section lists output variables for the phase-field fracture capability.

- Table 18.3.1 Nodal Variables for Phase-Field Fracture

- Table 18.3.2 Element Variables for Phase-Field Fracture

Table 18.3.1 Nodal Variables for Phase-Field Fracture
Name | Type | Comments
--- | --- | ---
`rxndiff_bound_constraint` | `Real` | bound constraint indicator (active if non-zero)
`rxndiff_bound_constraint_prev` | `Real` | previous iteration bound constraint indicator
`rxndiff_gradient_direction` | `Real` | PCG gradient direction
`rxndiff_mass` | `Real` | nodal phase field mass
`rxndiff_rhs` | `Real` | phase field evolution equation residual
`rxndiff_scratch_sol` | `Real` | PCG scratch solution
`rxndiff_search_dir` | `Real` | PCG search direction
`rxndiff_sol` | `Real` | phase field \(\phi\)

Table 18.3.2 Element Variables for Phase-Field Fracture
Name | Type | Comments
--- | --- | ---
`rxndiff_sol_grad` | `Vector_3D` | phase field gradient \(\nabla \phi\)
`rxndiff_sol_grad_ip` | `Real` | phase field gradient inner product \(\nabla \phi \cdot \nabla \phi\)
`rxndiff_sol_intpts` | `Real` | phase field at integration points