ZhETF, Vol. 138,
p. 5 (July 2010)
(English translation - JETP,
Vol. 111, No. 1,
available online at www.springer.com
ON BOUND STATE COMPUTATIONS IN THREE- AND FOUR-ELECTRON ATOMIC SYSTEMS
Frolov A.M., Wardlaw D.M.
Received: October 30, 2009
A variational approach is developed for bound state calculations in three- and four-electron atomic systems. This approach can be applied to determine, in principle, an arbitrary bound state in three- and four-electron ions and atoms. Our variational wave functions are constructed from four- and five-body Gaussoids that respectively depend on six (r12, r13, r14, r23, r24, r34) and ten (r12, r13, r14, r15, r23, r24, r25, r34, r35 and r45) relative coordinates. The approach allows operating with different numbers of electron spin functions. In particular, the trial wave functions for the 1S states in four-electron atomic systems include the two independent spin functions χ1 = α β α β + β α β α - β α α β - α β β α and χ2 = 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 23S states in four-electron atomic systems.