First of all, thanks for your reply.
I'd like to say that I know the Physics package and I think it's fantastic. I have done a great deal in him, especially in General Relativity. I have also followed the launch of Maple 2017 and its news!
I can say that I know the commands that you have indicated.
Initially, I tried to use the Physics package, but in it I can not reproduce a certain result.
Starting from this metric
I need to get this
With this definition
Unfortunately, the Physics package does not reproduce these results in the same way. So I had to resort to the grtensor, but I can not define all the components of the tensor.