Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Impact Ionization in ZnS   The impact ionization rate and its orientation dependence in k space is
calculated for ZnS. The numerical results indicate a strong correlation to the
band structure. The use of a q-dependent screening function for the Coulomb
interaction between conduction and valence electrons is found to be essential.
A simple fit formula is presented for easy calculation of the energy dependent
transition rate.

15
The categories of this paper are: nucl-ex
8
The categories of this paper are: hep-ex
11
The categories of this paper are: hep-lat
7
The categories of this paper are: hep-th
18
The categories of this paper are: econ
35
The categories of this paper are: mtrl-th
29
The categories of this paper are: funct-an
12
The categories of this paper are: nucl-th
27
The categories of this paper are: comp-gas
17
The categories of this paper are: q-fin
37
The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
23
The categories of this paper are: solv-int
14
The categories of this paper are: math-ph
6
The categories of this paper are: astro-ph
19
The categories of this paper are: eess