Correlation energy CPMET

CEP A98,104 represents one of the most successful approaches to the calculation of the correlation energy of molecules from the viewpoint of accuracy and the expenditure of computer time. CEPA may be looked upon as an approximation of CPMET. Again the wave function is assumed to have the form... 

CPMET is obviously a nonvariational method. However, the advantage of having an upper bound to the energy is probably not so important when the method is accurate enough to give the correlation energy with an accuracy of a few percent. 

This equation, along with the definition of the symbol idS, c > given in Eq. (5.53), and the expression for the correlation energy in Eq. (5.48a) are the equations of Coupled-Pair Many-Electron Theory (CPMET), which is... 

---