Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Continual Model of Medium IV: Calculation of analytical gradients for
  solvation energy over atomic coordinates   In the given paper we describe methods finding analytical gradients
(derivatives) of solvation energy over atomic coordinates. It is made both for
not polar energy and for the polar energy found by methods PCM, COSMO and SGB.
These gradients are searched with use of analytical gradients of parameters
(coordinates, normal vectors and squares) the surface meshes. The surface
meshes are located on both the optimal smooth molecular surfaces: solvent
excluded surface (SES) and surface solvent accessible surface (SAS) received
from SES. These surfaces are found by methods of primary and secondary rolling
according to the algorithm described in the previous papers of the series.

15
The categories of this paper are: nucl-ex
20
The categories of this paper are: acc-phys
2
The categories of this paper are: math
21
The categories of this paper are: adap-org
27
The categories of this paper are: comp-gas
32
The categories of this paper are: atom-ph
4
The categories of this paper are: cond-mat
17
The categories of this paper are: q-fin
5
The categories of this paper are: gr-qc
13
The categories of this paper are: quant-ph
7
The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol
16
The categories of this paper are: stat
18
The categories of this paper are: econ
28
The categories of this paper are: alg-geom
37
The categories of this paper are: supr-con