Three dimensions:

Three-dimensional infinite square well:
E = E_x + E_y + E_z.    E = n_x²π²ħ²/(2mL_x²)  + n_y²π²ħ²/(2mL_y²) + n_z²π²ħ²/(2mL_z²).  

Orbital angular momentum:
In three dimensions, for  a potential energy function U(x,y,z) = U(r), the solutions of the time-independent Schroedinger equation are
ψ_nlm(r,θ,ϕ) = R_nl(r)Y_lm(θ,ϕ).

The spherical harmonics Y_lm(θ,ϕ) are eigenfunctions of the operator L², which is the operator for the square of the magnitude of the orbital angular momentum.
L²Y_lm(θ,ϕ) = l(l+1)ħ²Y_lm(θ,ϕ),  l = 0, 1, 2, ... .
The magnitude of the angular momentum is quantized.  The only possible outcomes of a measurement are  (l(l + 1)ħ².

The Y_lm(θ,ϕ) are also eigenfunctions of the operator L_z, which is the operator for the z-component of the orbital angular momentum.
L_zY_lm(θ,ϕ) = mħY_lm(θ,ϕ),  m = 0, ±1, ±2, ... ±l. 
The  z-component  of the angular momentum is quantized.  The only possible outcomes of a measurement are mħ.

Tunneling:
The transmittance T is the probability that a particle will tunnel through a barrier. 
T = exp(-2bL) with b = (2m(U₀-E)/ħ²)^1/2. 
T decreases as the difference between the height of the barrier U₀ and the particle energy increases, and it is smaller for a more massive particle and for a wider barrier.