Theoretical study on microhydration of SeO42-: On the number of water molecules necessary to stabilize the dianion

► Microhydration of SeO42-·nH2O clusters are studied at B3LYP/Aug-cc-pvtz level. ► Higher size cluster (n > 3) contains cyclic water ring. ► One water molecule is necessary to stabilize the dianion against electron loss. ► Microscopic theory based expression predicts the instability of bare SeO42-. ► VDE for a wide range of cluster sizes including the bulk is extracted.