关注：

1）是否只有先考虑自旋了，才可能考虑旋轨耦合和强关联加U计算呢

2）

   手册解读：

LDAUTYPE=2 (Default): The simplified (rotationally invariant) approach to the LSDA+U, introduced by Dudarev et al. [91]. This flavour of LSDA+U is of the following form:  

LSDA   局域自旋密度近似，貌似必须考虑自旋后加U

LDAUTYPE=4: Same as LDAUTYPE=1, but LDA+U instead of LSDA+U (i.e. no LSDA exchange splitting). In the LDA+U case the double counting energy is given by,

LDA  局域密度近似，貌似可以不考虑自旋。

但Valenhou的观点： 当比较考虑自旋与否的能量差别时，最好选用相同的LDAUTYPE=2设置