Each of the questions (a)-(f) refers to the accompanying figure, which represents a portion of a two-dimensional crystal. (a) Indicate with conventional symbols, over a sufficiently large portion of the pattern to cover at least one unit cell, the location of all of the nontrivial symmetry elements that are present in the pattern. (b) Identify the plane group for this structure. (c) Draw on the figure the basis vectors t1 and t2 that define the conventional unit cell for this structure and clearly outline the resulting cell. (d) Specify the contents of the unit cell for this structure by giving the Wyckoff symbols for each species in the unit cell. Estimate any fractional coordinates necessary in your answer. (e) How many atoms of each type are there in the conventional unit cell? What is the stoichiometric formula for this crystal? (f) What constraints do the symmetry elements present in the pattern place on the lattice type? Is this consistent with the observed arrangement of atoms