Comparing variance components of crossed effects models fit with lme4 and nlme

library(lme4, warn.conflicts=F)

## Loading required package: Matrix

library(nlme, warn.conflicts=F)

m_lme4 <- lmer(diameter ~ 1 + (1 | plate) + (1 | sample), data = Penicillin)
m_lme4

## Linear mixed model fit by REML ['lmerMod']
## Formula: diameter ~ 1 + (1 | plate) + (1 | sample)
##    Data: Penicillin
## REML criterion at convergence: 330.8606
## Random effects:
##  Groups   Name        Std.Dev.
##  plate    (Intercept) 0.8467  
##  sample   (Intercept) 1.9316  
##  Residual             0.5499  
## Number of obs: 144, groups:  plate, 24; sample, 6
## Fixed Effects:
## (Intercept)  
##       22.97

m_nlme <- lme(diameter ~ 1, random = list(plate = ~ 1, sample = ~ 1), data = Penicillin)
m_nlme

## Linear mixed-effects model fit by REML
##   Data: Penicillin 
##   Log-restricted-likelihood: -306.628
##   Fixed: diameter ~ 1 
## (Intercept) 
##    22.97222 
## 
## Random effects:
##  Formula: ~1 | plate
##         (Intercept)
## StdDev:   0.3083643
## 
##  Formula: ~1 | sample %in% plate
##         (Intercept)  Residual
## StdDev:    1.921869 0.5828833
## 
## Number of Observations: 144
## Number of Groups: 
##             plate sample %in% plate 
##                24               144