# Hamiltonian Matrix

In the volume III of R Feynman series which is on Quantum Mechanics , please explain to me the eq.8.43 given on page 1529, i know how we got the equation but the 2nd part of 1st equation (H12)C2, what does it mean ?

## Answers and Replies

Gokul43201
Staff Emeritus
$$\mathcal{H} \equiv \left( \begin{array}{cc} H_{11} & H_{12}\\ H_{21} & H_{22} \end{array} \right)$$