On the Correlation Problem in Atomic and Molecular Systems. Calculation of Wavefunction Components in Ursell-Type Expansion Using Quantum-Field Theoretical Methods

摘要: A method is suggested for the calculation of matrix elements logarithm an operator which gives exact wavefunction when operating on in one‐electron approximation. The based use creation and annihilation operators, hole—particle formalism, Wick's theorem, technique Feynman‐like diagrams. connection this with configuration‐interaction as well perturbation theory quantum‐field theoretical form discussed. applied to simple models nitrogen benzene molecules. results are compared those obtained considering all possible configurations within chosen basis functions.