The consequences of neglecting permutation symmetry in the description of many‐electrons systems

Abstract

AbstractThe consequences of neglecting the permutation symmetry of the Hamiltonian of many‐electrons system are examined. From the comparison of wave functions based on methods, which take (generalized valence bond [GVB]) and do not take (Hartree‐Fock) the permutation symmetry into account, it is shown that neglecting the permutation symmetry leads to false concepts, misinterpretations, and unjustifiable approximations when dealing with many‐electrons systems, atoms, and molecules. In particular, it is shown that how the double occupancy of atomic and molecular orbitals, the exchange integral, the correlation energy, and the so‐called “nondynamic” correlation energy are related to neglecting the permutation symmetry.