(color online) As an example, both the vector magnetic field strength and the four possible directions have preset values , θ = 3π/16, and four possible azimuth angle ϕ = 3π/8, π ±3π/8, or 2π − 3π/8 satisfying mirror symmetry about ¹⁴N–V–¹³C plane. The four possible angles could be clearly discriminated by the evolutionary processes of preparing two different initial nuclear spin state . The probability evolution is shown by the envelope. (a1)–(a4), the initial state (b1)–(b4), the initial state . Notations are defined in the main text.