# The meaning of magnetic quantum numbers' values

The $$\mathrm{m_l}$$ values in quantum mechanics, $$1, 0, -1$$ for p orbitals for example, do they refer to specific orbitals? Like, does $$\mathrm{m_l} = 1$$ refer specifically to $$\mathrm{p_x, m_l} = 0$$ refers to $$\mathrm{p_y}$$, and $$\mathrm{m_l} = -1$$ refer to $$\mathrm{p_z}$$? Or are these values arbitrarily defined?

• They are not arbitrary, nor do they refer to specific orbitals one to one. Indeed, $m_l=0$ for $p_z$; now, $p_x$ and $p_y$ are the linear combinations of the orbitals with $m_l=\pm1$. – Ivan Neretin Apr 13 at 2:27