# Standard Deviation

calculate the standard deviation $\sigma = \sqrt{<\hat{O}^2>- <\hat{O}>^2}$ of an operator $\hat{O}$

## Inputs

• $\hat{O}$: Operator - the operator to calculate the standard deviation of
• $\psi$: state - the state the system is in when we want the standard deviation

## Outputs

• Scalar: real number - the calculated standard deviation

## Content

For convenience, the node displays its result directly