what is the configuration of second excited state of the element isoelectronic with O₂ or P^- or Cl⁺ is?

Isoelectronic species are those which have same number of electrons or similar electron configuration irrespective of nature of elements involved.
O²,P^- and Cl⁺ are isoelectronic as they all have 16 electrons.They all have configuration which is-- [Ne] 3s²,3P⁴
Now the configuration of second excited state of the elment which is isoelectronic with all the above species will be-- [Ne] 3s¹,3P³,3d²

Dear student in excited state,an electron jumps from lower energy orbital to higher energy orbital.In this case the ground state configuration is [Ne]3s2,3p4.Now in first excited state first e-from 3p will jump to 3d orbital as this is higher energy orbital and in second excited state another e- from 3s orbital will then jump to second 3d orbital as after first excitation all 3p orbitals remained singly filled ,so second excitation occurs from 3s orbital and configuration becomes-[Ne]3s1,3p3,3d2.
It can’t be [Ne]3s2,3p6 as in such case electron from lower 2p orbitals shows excitation which is not possible as it first occurs from outer energy orbitals and after that it can’t be written as [Ne],as the configuration gets changed which will no longet resemble the noble gas Ne.