where V ^ ^ = V = V ( r , t ) , is the potential energy operator and T ^ ^ = p ^ ^ ⋅ ⋅ p ^ ^ 2 m = p ^ ^ 2 2 m = − − ℏ ℏ 2 2 m ∇ ∇ 2 , is the kinetic energy operator in which m is the mass of the particle, the dot denotes the dot product of vectors, and p ^ ^ = − − i ℏ ℏ ∇ ∇ , is the momentum operator where a ∇ ∇ is the del operator. The dot product of ∇ ∇ with itself is the Laplacian ∇ ∇ 2 . In three dimensions using Cartesian coordinates the Laplace operator is ∇ ∇ 2 = ∂ ∂ 2 ∂ ∂ x 2 + ∂ ∂ 2 ∂ ∂ y 2 + ∂ ∂ 2 ∂ ∂ z 2