# Translate glmer (lme4) model specification into MCMCglmm

I am having some computational trouble estimating the following model with the glmer function in lme4:

glmer(Y ~ x1*x2 + x2*x3 + (1+x1+x2|class) + (1|obs), family=poisson)
• where class refers to my groupings,
• obs refers to observation (because I would like to an observation-level random effect).

I'd like to try the MCMCglmm package (without deep knowledge of MCMC unfortunately), but cannot figure out how to specify the random effects. So far, my draft command is:

MCMCglmm(fixed = Y ~ x1*x2 + x2*x3,
random = ~ class + x1:class + x2:class + obs, family="poisson")