Based on the hole-particle correspondence an approximate so-called doubly con-tracted CI scheme is proposed. Examples calculated based on the doubly contracted CI (DCCI) scheme show that the number of configurations after contraction is reduced by three orders of magnitude, and the computation time is reduced by an order of magnitude. The examples also show that compared with experiments the DCCI and uncontracted CI have similar and reason-able accuracy to some spectroscopic parameter.
WANG Yubin1, HAN Huixian1, ZHAI Gaohong2 ,SUO Bin1 & WEN Zheny1,2 1. Institute of Modern Physics, Northwest University, Xian 710069, China