How is to define the lme model syntax .

#1
The following model assumes that the covariance between the random intercepts and random slopes across Subjects is Zero .

Code:
lmer(Reaction ~ Days + (Days||Subject), sleepstudy)
How can I write the same model by "lme" function under nlme pacakge assuming zero covariance between the random intercepts and random slopes across Subjects ?

Thanks! Regards .