What is indicated by $\psi$ for atomic and molecular orbitals? How is the molecular orbital obtained by the Schrodinger wave equation?

(N/A) Atomic orbitals and $\psi$: According to wave mechanics,atomic orbitals are expressed by wave functions $(\psi)$,which represent the amplitude of the electron waves. These are obtained from the solution of the Schrodinger wave equation.
Molecular orbitals and $LCAO$: The Schrodinger wave equation cannot be solved exactly for any system containing more than one electron. Since molecular orbitals are one-electron wave functions for molecules,they are difficult to obtain directly from the Schrodinger wave equation. To overcome this,an approximate method known as the Linear Combination of Atomic Orbitals $(LCAO)$ is used.
$LCAO$ is a method used to approximate molecular orbitals for systems with more than one electron,as a practical approach to the Schrodinger wave equation.