SetDirectory[NotebookDirectory[]];
file = FileNames["*.dat", NotebookDirectory[]];
func[file_String /; FileExistsQ[file]] :=
 Module[{data, dataT}, data = Import[file, "Table", HeaderLines -> 2];
   dataT = Transpose[data];
  dataT = {dataT[[1]]*10, dataT[[2]]*10,
    dataT[[3]]}; (*je converti de angtroms a nano*)

  dataT[[3]] = Rescale[dataT[[3]], MinMax[dataT[[3]]], {-1., 1.}];
  data = Transpose[dataT];

  graph = ListDensityPlot[data,
    PlotLabel -> FileBaseName[file],
    PlotRange -> {{-0.5, 0.5}, {-0.5, 0.5}, {-1., 1.}},
    ColorFunction -> (ColorData[{"TemperatureMap", {-0.8, 0.8}}])]

  ]

func /@ file