Monoterpene synthase involved in the biosynthesis of volatile organic compounds (PubMed:25956881). Mediates the conversion of (2E)-geranyl diphosphate (GPP) into the acyclic monoterpene, geraniol (PubMed:25956881). Does not use (2E,6E)-farnesyl diphosphate (FPP) as substrate (PubMed:25956881). (2E)-geranyl diphosphate + H2O = (2E)-geraniol + diphosphate Binds 3 Mg(2+) ions per subunit. Secondary metabolite biosynthesis; terpenoid biosynthesis. Monomer. The Asp-Asp-Xaa-Xaa-Asp/Glu (DDXXD/E) motif is important for the catalytic activity, presumably through binding to Mg(2+). Belongs to the terpene synthase family. Tpsg subfamily.