Any particular basis of formula_1 vectors may be represented by a matrix formula_2, whose columns are the basis vectors formula_3. In the fully dimensional case where the number of basis vectors is equal to the dimension of the space they occupy, this matrix is square, and the volume of the fundamental parallelepiped is simply the absolute value of the determinant of this matrix formula_4. If the number of vectors is less than the dimension of the underlying space, then volume is formula_5. For a given lattice formula_6, this volume is the same (up to sign) for any basis, and hence is referred to as the determinant of the lattice formula_7 or lattice constant formula_8.