Simple forms of SLOCC equivalent four-qubit \c{hi} state
  Some simple structure of maximally four-qubit state is presented. Using stochastic local operations and classical communication (SLOCC) invariants, it is can be shown those simple structure of maximally four-qubit state is SLOCC equivalent to four-qubit \c{hi} state. 
Xin-Wei Zha, Jian-Xia Qi and Yun-Guang Zhang
quant-ph