Thanks a lot for your quick reply, Concerning nrx1s, nrx2s, nrx3s, nrxxs I imagine the following replacements hold: nrx1s => dffts%nr1x nrx2s => dffts%nr2x nrx3s => dffts%nr3x nrxxs => dffts%nnr Regards, Riccardo Piombo Post doc researcher in Condensed Matter Physics at Sapienza University of Rome