Low-Lying and Core Excited Doublet States of Lithium Atom in Various Plasma Environments

New study is made for the impact of three different plasma potentials on the low-lying and core excited doublet states of the lithium atom using the variational Monte Carlo method. The considered low-lying excited doublet states include the states: 1s2ns, 1s2np, and 1s2nd, whereas the core excited states include the states: 1s n1l1n1l2 and 1s n1l1n2l2. Also, the three used plasma potentials are: screened Coulomb, exponential cosine screened Coulomb, and Hulthen potentials. The energy eigenvalues of the excited states are evaluated freely and under the influence of the plasma potentials using suitable trial wave functions including the spin and the correlated (electron-electron repulsion) parts. In addition, a suggested effective -plasma factor is considered in the wave function regarding the exponential cosine screened Coulomb potential model due to the dense plasma particle interactions. Interesting relative ordering of eigenvalues is reported for the excited states of the lithium atom corresponding to the three different screened Coulomb potentials.