Hi
I do not think this is Centromerus semiater.
You can look at Metarsus I. and see if it has a thorn dorsal, Centromerita species have this. Moreover, you can check how many thorns there is on Tibia 1.
A species resembling the Centromerita concinna, it is easy to check this because it has many thorns on the underside of the Tibia 1. For comparison look at Pierre's photos on his website.
Greeting
Harald