The new phase NaBi3V2O10 is reported; it was synthesised by oxide reac
tion at 600 degrees C and is triclinic with a = 7.2026(10), b = 7.0600
(9), c = 5.5312(6) Angstrom, alpha = 84.542(12), beta = 113.318(11) an
d gamma = 112.267(12)degrees; it is an oxide ion conductor with conduc
tivity of ca. 1.5 mS cm(-1) at 675 degrees C.