Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A more accurate measurement of the $^{28}$Si lattice parameter   In 2011, a discrepancy between the values of the Planck constant measured by
counting Si atoms and by comparing mechanical and electrical powers prompted a
review, among others, of the measurement of the spacing of $^{28}$Si {220}
lattice planes, either to confirm the measured value and its uncertainty or to
identify errors. This exercise confirmed the result of the previous measurement
and yields the additional value $d_{220}=192014711.98(34)$ am having a reduced
uncertainty.

20
The categories of this paper are: acc-phys
19
The categories of this paper are: eess
14
The categories of this paper are: math-ph
7
The categories of this paper are: hep-th
23
The categories of this paper are: solv-int
36
The categories of this paper are: cmp-lg
28
The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat
35
The categories of this paper are: mtrl-th
21
The categories of this paper are: adap-org
17
The categories of this paper are: q-fin
31
The categories of this paper are: ao-sci
27
The categories of this paper are: comp-gas
13
The categories of this paper are: quant-ph
25
The categories of this paper are: patt-sol
33
The categories of this paper are: plasm-ph