Hi Anto,
A simple search led me to some Limpidis Psathas people in Antofagasta, northern Chile.
Perhaps they are linked to your Dimitris Psathas, who may have renamed Demetrio Psathas, or Sazas, or Saso (which is a common surname)
They descend from Andrés Psathas Rapariakis (or Rapanakis) and Ergina Psatha Rapanakis. They are certainly dead, as one of their children was born 1937. Perhaps Andrés /and/ Ergina are cousins. Whatever they are, these are the only Psathas people in Chile.