<s>
This	O
is	O
one	O
of	O
the	O
main	O
reasons	O
that	O
most	O
multipolar	B-General_Concept
orderings	I-General_Concept
tend	O
to	O
be	O
non-colinear	O
.	O
</s>
<s>
Therefore	O
,	O
a	O
suggested	O
definition	O
of	O
antiferromagnetic	O
multipolar	B-General_Concept
ordering	I-General_Concept
is	O
to	O
flip	O
their	O
phases	O
by	O
,	O
i.e.	O
</s>
<s>
Calculation	O
of	O
multipolar	B-General_Concept
exchange	I-General_Concept
interactions	I-General_Concept
remains	O
a	O
challenging	O
issue	O
in	O
many	O
aspects	O
.	O
</s>
<s>
Currently	O
there	O
are	O
two	O
studies	O
implemented	O
first-principles	O
approach	O
to	O
explore	O
multipolar	B-General_Concept
exchange	I-General_Concept
interactions	I-General_Concept
.	O
</s>
