Description of the Fit Statistics Report uses the following notation:
Here y is the nx1 vector of observations, is a vector of fixed-effect parameters, γ is a vector of random-effect parameters, and ε is a vector of errors.
The vectors γ and ε are assumed to have a multivariate normal distribution where
and p is the rank of X. Use the residual likelihood only for model comparisons where the fixed effects portion of the model is identical. For more details, see Likelihood, AICc, and BIC in Statistical Details.
If there are problems with model convergence, a warning message is displayed below the fit statistics. Convergence Score Test shows the warning that suggests the cause and possible solutions to the convergence issue. It also includes a test of the relative gradient at the final iteration. If this test is non-significant, the model might be correct but not fully reaching the convergence criteria. In this case, consider using the model and results with caution. For more information, see Convergence Score Test.
Convergence Score Test

Help created on 9/19/2017