High Precision Study of K-Shell Some Atomic Systems

The present paper discuss two variational wavefunctions of K-shell atomic systems z=9-18. The first wavefunction deals with the Zeta-Roothaan-Hartree-Fock while the second one considered a simply correlated wavefunction. Several local properties have studied, for instance, radial correlation density function between the two wavefunctions, electron density at the nucleus, diamagnetic susceptibility, and nuclear magnetic shielding constants. We show how the physical properties for K-shell atoms affected by increasing the atomic number . All results are obtained via Mathematica program version 10.1.01.