Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Layered compounds AFBiS2: superior birefringent crystals   Stimulated by the discovery of the giant birefringence (GBF) in LaOBiS2 (H.
Wang, arxiv: 1304.5032), we check SrFBiS2 and find a superior birefringence up
to 1.28. Naturally, AF layer (i.e., SrF) is considered to be of important and
is demonstrated by the further study on AFBiS2 (A=Mg, Ca, Ba). Interestingly,
MgFBiS2 shows the largest birefringence of 1.65. Furthermore, the origin of GBF
is discussed in detail.

26
The categories of this paper are: bayes-an
11
The categories of this paper are: hep-lat
37
The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn
33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ
34
The categories of this paper are: chem-ph
24
The categories of this paper are: dg-ga
0
The categories of this paper are: hep-ph
29
The categories of this paper are: funct-an
15
The categories of this paper are: nucl-ex
35
The categories of this paper are: mtrl-th
32
The categories of this paper are: atom-ph
21
The categories of this paper are: adap-org