ZhETF, Vol. 138,
No. 1,
p. 5 (July 2010)
(English translation  JETP,
Vol. 111, No. 1,
p. 1,
July 2010
available online at www.springer.com
)
ON BOUND STATE COMPUTATIONS IN THREE AND FOURELECTRON ATOMIC SYSTEMS
Frolov A.M., Wardlaw D.M.
Received: October 30, 2009
A variational approach is developed for bound state calculations in three and fourelectron atomic systems. This approach can be applied to determine, in principle, an arbitrary bound state in three and fourelectron ions and atoms. Our variational wave functions are constructed from four and fivebody Gaussoids that respectively depend on six (r_{12}, r_{13}, r_{14}, r_{23}, r_{24}, r_{34}) and ten (r_{12}, r_{13}, r_{14}, r_{15}, r_{23}, r_{24}, r_{25}, r_{34}, r_{35} and r_{45}) relative coordinates. The approach allows operating with different numbers of electron spin functions. In particular, the trial wave functions for the ^{1}S states in fourelectron atomic systems include the two independent spin functions χ_{1} = α β α β + β α β α  β α α β  α β β α and χ_{2} = 2 α α β β + 2 β β α α  β α α β  α β β α  β α β α  α β α β. We also discuss the construction of variational wave functions for the excited 2^{3}S states in fourelectron atomic systems.

